The potentially revolutionary Celera 500L aircraft(thedrive.com)
thedrive.com
The potentially revolutionary Celera 500L aircraft
https://www.thedrive.com/the-war-zone/36016/the-potentially-revolutionary-celera-500l-officially-breaks-cover
251 comments
Definitely some extraodinary claims that will require extraordinary evidence to prove. Especially getting 20+ mpg for 4500 miles, while flying at 450mph, which is near the top end of what piston/propeller aircraft are capable of. For reference, the P51 (one of the fastest fighters of WWII) had a comparable top speed. The Piaggio Avanti [0] has a somewhat similar design and top speed (460 high speed cruise), but has twin turboprops and a far shorter range and far lower claimed mpg.
[0] https://en.wikipedia.org/wiki/Piaggio_P.180_Avanti
[0] https://en.wikipedia.org/wiki/Piaggio_P.180_Avanti
The Piaggio II (https://www.aircraftcompare.com/aircraft/piaggio-p180-avanti...) is missing several modern aerodynamic and efficiency features like winglets and gets 15MPG and has a 1600 Mile range. Significantly beating it’s fuel efficiency at similar speeds seems reasonable just eyeballing the two designs. Getting the full 20MPG at 450MPH might be a stretch, but it’s not all that unreasonable.
Also, higher aerodynamic efficiency means lower HP requirements. Moving that weight savings to fuel can boost range even further.
PS: Winglets are actually really old technology. It’s making the trade offs worth it including significantly increased weight at the wing tip that’s new.
Also, higher aerodynamic efficiency means lower HP requirements. Moving that weight savings to fuel can boost range even further.
PS: Winglets are actually really old technology. It’s making the trade offs worth it including significantly increased weight at the wing tip that’s new.
I’m not sure those mpg numbers are correct: the more fuel efficient Piaggio EVO update, with winglets etc, in the extended range version can hold about 450 gallons of Jet A and has a 1770nm range, so even with plenty of reserves that doesn’t get it anywhere above half of 15mpg (from what I can find IFR reserve comes out to 75 gallons, thus 4.72mpg nautical or 5.4 statute).
Which is why the jump in efficiency would be so extraordinary.
Which is why the jump in efficiency would be so extraordinary.
I recall from the last time this plane hit the news cycle that it is designed to cruise at 60,000 feet where air density is lower and better fuel efficiency can be had.
To put that claim into context the manned single engine piston height record is held by a specially modified Rutan Long Ez and was around 35,000ft.
Prop planes don’t work well at higher elevation. There’s nothing for the prop to work against. It’s why jet engines, with their compression, work better.
Props work better than jets at low elevation where the span of a propeller can work against a lot of high density air.
Props work better than jets at low elevation where the span of a propeller can work against a lot of high density air.
Turboprops are less fuel efficient, they just have a higher power to weight ratio than piston engines.
Much of the improved efficiency comes from the engine[1], which claims "50% lower fuel burn compared to turbine engines in the same power category".
The engine company is German and so we can make lots of jokes about German companies' fuel efficiency claims I guess.
Nevertheless, it has been around since 2012 and is used in a few planes already, so presumably there is some measurable improvement there or they'd have taken the claim down by now?
For comparison, this engine has a Specific fuel consumption of 210 g/kW/h, while a P&W PT6A-6 (older, slightly more powerful: 431 kW vs 368kW) has 0.408 kg/kW/hr[2]
[1] https://red-aircraft.com/?lang=en
[2] http://www.all-aero.com/index.php/contactus/64-engines-power...
The engine company is German and so we can make lots of jokes about German companies' fuel efficiency claims I guess.
Nevertheless, it has been around since 2012 and is used in a few planes already, so presumably there is some measurable improvement there or they'd have taken the claim down by now?
For comparison, this engine has a Specific fuel consumption of 210 g/kW/h, while a P&W PT6A-6 (older, slightly more powerful: 431 kW vs 368kW) has 0.408 kg/kW/hr[2]
[1] https://red-aircraft.com/?lang=en
[2] http://www.all-aero.com/index.php/contactus/64-engines-power...
Still, a plane with half the aerodynamic drag and twice the BSFC is only getting 4x the fuel efficiency, not the ~10x they're claiming. Even if they're making a bit of "free" thrust from their cooling system (which has been a thing since WWII), I don't see what accounts for the rest, even ignoring that the Celera likely has a significant increase in frontal area due to the standing-height cabin.
Re “free thrust/WWII”: Real Engineering recently did a great summary of the P47 Thunderbolt intercooler and general craziness of the engine at https://youtu.be/IwqTN5fhMR8
They are claiming slightly under 10x fuel efficiency compared to a jet (2-3 mpg vs 18-25 mpg).
That doesn't seem completely unreasonable.
A Pilatus PC-12 (which is the turoprop competition here) NXG gets around 4.3 mpg.
That doesn't seem completely unreasonable.
A Pilatus PC-12 (which is the turoprop competition here) NXG gets around 4.3 mpg.
>Especially getting 20+ mpg for 4500 miles, while flying at 450mph
That's not what they're claiming though. They're claiming that:
1. 20+ mpg
2. maximum speed of 450 mph
3. range of 4500 miles
are possible individually, not that 1+2+3 are possible all at the same time.
That's not what they're claiming though. They're claiming that:
1. 20+ mpg
2. maximum speed of 450 mph
3. range of 4500 miles
are possible individually, not that 1+2+3 are possible all at the same time.
Sure, there are all kinds of trade offs between speed, range, useful load, altitude, burn rate, etc. But it’s really the combination of 450, 4500, and 20+ that would make this plane revolutionary. Otherwise it wouldn’t be all that interesting. And if we are to take seriously their claim of competing with commercial aviation, then it would really have to perform pretty close to all three of those numbers at the same time to even have a chance.
Edit: just to add a few numbers from the back of my napkin. To go 4500 miles, it would probably need to do 20mpg anyway. That’s 225 gallons of fuel. JetA is 6.7lb/gl, so ~1500lb. Not sure a small plane could carry a whole lot more than that without giving up all the useful load. And if it can only cruise at ~300mph in order to go 4500 miles, then we’re looking at a 15-hour flight in a pretty confined space with likely fairly basic amenities. It’s not exactly bringing back the glamour of aviation.
Edit: just to add a few numbers from the back of my napkin. To go 4500 miles, it would probably need to do 20mpg anyway. That’s 225 gallons of fuel. JetA is 6.7lb/gl, so ~1500lb. Not sure a small plane could carry a whole lot more than that without giving up all the useful load. And if it can only cruise at ~300mph in order to go 4500 miles, then we’re looking at a 15-hour flight in a pretty confined space with likely fairly basic amenities. It’s not exactly bringing back the glamour of aviation.
I'd take any sleeping pod any time, even if I had to bring my own sandwiches, piss into a bottle and have 0 entertainment than sit for more than 8 hours in economy flight of any current airline.
I'd similarly prefer a low-headroom bunk bed. I think the problem is bracing for take-off and landing and evacuations.
Well, from London to New York is apparently about 3500 miles, and a 15 hour journey for that sounds reasonable.
A single engine plane is most likely not going to be used for ocean crossings regularly, for safety reasons, even if it is technically capable of it. Additionally, I'm not sure it has enough spare fuel reserves to make the trip with enough margin for error or unforeseen circumstances.
Single engine aircraft with a range of around 800 miles are regularly ferried across the Atlantic. Now, I'm not for a minute suggesting that this is an everyday pleasure flight, it's something which takes planning, preparation and additional equipment. However, all I'm pointing out is that range would be the least of your problems if any of the claims prove true.
If you are interested this site gives a good overview of the routes and the legs involved http://220kts.com/ferry-flights/atlantic-ferry-routes.html
If you are interested this site gives a good overview of the routes and the legs involved http://220kts.com/ferry-flights/atlantic-ferry-routes.html
Ferrying is not a paying passenger flight, correct?
How would single-engine craft comply with ETOPS - the relevant standard for passenger flights, or equivalent?
https://en.wikipedia.org/wiki/ETOPS
https://aerosavvy.com/etops/
How would single-engine craft comply with ETOPS - the relevant standard for passenger flights, or equivalent?
https://en.wikipedia.org/wiki/ETOPS
https://aerosavvy.com/etops/
The short answer is they don't and it's pointless to ask about it since these flights are conducted under part 91 for private aviation. There is almost no charter or scheduled flights allowed on single engine aircraft in Europe and the few that do exist are using single engine turbines on an exemption (the exemption is based on the fact turbines have a demonstrated order of magnitude better reliability).
> There is almost no charter or scheduled flights allowed on single engine aircraft in Europe
So, without new regulation, this aircraft will not carry out "charter or scheduled flights in Europe" ?
So, without new regulation, this aircraft will not carry out "charter or scheduled flights in Europe" ?
This has changed relatively recently (2017) in the EASA rules and single-engine IFR charter flying is possible without special exemptions as long as the engine has demonstrated good reliability (basically it means turbine engines).
This airplane has a "2 in 1" engine. Two separate engines running on one physical engine block. So there is some engine redundancy.
yes but that really only matters if the second "engine" produces enough power for maneuvering if the first one fails. Plus, there is still mechanical interconnectedness so it isn't truly redundant. That said it is likely far safer than a traditional twin, the axiom with those is if you lose one engine the second will fly you all the way to the scene of the crash.
There's a link to the motor manufacturer in the article (but it's down right now). As I recall the two motors are identical with no common parts other than the engine block.
Especially if you're saving time at either end by skipping all the Heathrow delays (long security checks, baggage check, etc)
Only if it has cryosleep chambers on-board.
TFA did not say maximum speed 450mph, it said "maximum cruising speed of at least 450mph" Still doesn't mean it gets 18-25mpg at 450.
If it can realistically do half of 4500 miles at 450mph, there are a lot of interesting routes (Gets you as far as Tel-Aviv from London, Boston to Phoenix, or Los Angeles to Miami).
Using that completely-pulled-out-of-my-ass number of half the range at 450, and assuming quadratic drag, the full range would be at about 300mph, so a roughly 12 hour flight from New York to London at a cost of $5k.
If it can realistically do half of 4500 miles at 450mph, there are a lot of interesting routes (Gets you as far as Tel-Aviv from London, Boston to Phoenix, or Los Angeles to Miami).
Using that completely-pulled-out-of-my-ass number of half the range at 450, and assuming quadratic drag, the full range would be at about 300mph, so a roughly 12 hour flight from New York to London at a cost of $5k.
$5k plus pilots (I’d want two for a transatlantic flight). And you’d still be stuck inside a very small space for 12 hours, with what’s likely to be a porta-potty level lavatory and minimalist galley. Oh, and a single piston engine, which is less reliable than turbines, over a lot of very cold water. Not sure that would be the best use case for this plane.
Plus airports, airspace, immigration, depreciation, insurance. So more like 20k.
12 hours transatlantic is probably worse than coach (or premium coach at least) transatlantic in 7 hours for most cases.
With these specs (which are completely fictional at this point), it's the size and cost of a light-jet with the speed and range of a mid-sized jet, which is a under-served niche with the increasing numbers of people in the "very wealthy, but not quite embarassingly wealthy"
With these specs (which are completely fictional at this point), it's the size and cost of a light-jet with the speed and range of a mid-sized jet, which is a under-served niche with the increasing numbers of people in the "very wealthy, but not quite embarassingly wealthy"
Well, the size of aircraft certainly allows for fully enclosed, proper lavatory. CJ3 used for size comparison, has one.
The single engine is a concern.
Something like Garmin Autonomí might eventually allow for single pilot flights while maintaining a reasonable level of safety.
https://www.garmin.com/en-US/autonomi/
Something like Garmin Autonomí might eventually allow for single pilot flights while maintaining a reasonable level of safety.
https://www.garmin.com/en-US/autonomi/
Everything deserves to have a Version 1.0
I have high hopes for the future efforts
I have high hopes for the future efforts
I'm calling bullshit. Compare it to the TBM900 which has a 900hp turbine engine and vastly similar layout. There is no way they can go 60 knots faster on 300 less horse power.
And even if they somehow pull off that trick, that short skinny wing will make the MU-2 feel like a safe family minivan.
And even if they somehow pull off that trick, that short skinny wing will make the MU-2 feel like a safe family minivan.
If they reduce drag, which is exactly what they are claiming to have achieved, that would reduce the amount of horse power needed to overcome that drag. Less HP translates into better fuel economy.
Basically this plane has the engine mounted on the back, which means center of gravity and wing position are quite a bit different. The nose cone looks very streamlined and crucially the wings are in front of the vortex produced by the prop. I'm guessing that that adds up to a bit of reduction in drag. The reason many planes have the engines mounted on the other side probably have to do with things like cooling, engine size, and other practical concerns.
Basically this plane has the engine mounted on the back, which means center of gravity and wing position are quite a bit different. The nose cone looks very streamlined and crucially the wings are in front of the vortex produced by the prop. I'm guessing that that adds up to a bit of reduction in drag. The reason many planes have the engines mounted on the other side probably have to do with things like cooling, engine size, and other practical concerns.
They are claiming improvements across almost all areas. If it flew as fast and as far as the competition on 50% less fuel, that would be amazing. If it flew 60 knots faster in the same fuel and payload, awesome!
However, they are claiming improvements across the board. 3x the range, significantly faster, flies higher, uses less fuel. It doesn't pass a sniff test.
Compare it to the Grob Strato 2c. Notice how long the wings are by comparison? This is a feature of nearly all subsonic high altitude aircraft. Also notice the how long the props are on the Grob, another feature of high altitude aircraft conspicuously missing on this aircraft.
Pusher aircraft are not new. In fact they are as old as powered aviation itself. They generally aren't significantly more efficient.
https://en.m.wikipedia.org/wiki/Grob_Strato_2C
However, they are claiming improvements across the board. 3x the range, significantly faster, flies higher, uses less fuel. It doesn't pass a sniff test.
Compare it to the Grob Strato 2c. Notice how long the wings are by comparison? This is a feature of nearly all subsonic high altitude aircraft. Also notice the how long the props are on the Grob, another feature of high altitude aircraft conspicuously missing on this aircraft.
Pusher aircraft are not new. In fact they are as old as powered aviation itself. They generally aren't significantly more efficient.
https://en.m.wikipedia.org/wiki/Grob_Strato_2C
The layout/payload may be similar to a TBM, but I'm guessing the wing loading and cruise altitude will be higher. So it's definitely feasible to go faster on less power.
Aerodynamic drag is a square relation so the difference in drag there is about 40%. With 65% of the power.
I think occam's razor applies here. Either the aerodynamics of reasonably modern aircraft designs leave a huge amount on the table or this startup is telling fibs.
There are other reasons to be suspicious, modern diesel engines rely on a large amount of turbo charging to achieve sea level rated power, it's difficult to believe they are able to maintain this rated power to 50,000ft or 60,000ft. (In the case of the TBM the engine is actually capable of about 1300hp at sea level but is "flat rated" to what it can maintain at altitude).
Finally, almost all high altitude aircraft have long wings (think the U2 as that is not far from what we are talking about here). Adding longer wings typically increases high altitude performance (there are aircraft with model variants where the wings got longer, like the twin commander). This aircraft appears to have borrowed a couple of surfboards.
I think occam's razor applies here. Either the aerodynamics of reasonably modern aircraft designs leave a huge amount on the table or this startup is telling fibs.
There are other reasons to be suspicious, modern diesel engines rely on a large amount of turbo charging to achieve sea level rated power, it's difficult to believe they are able to maintain this rated power to 50,000ft or 60,000ft. (In the case of the TBM the engine is actually capable of about 1300hp at sea level but is "flat rated" to what it can maintain at altitude).
Finally, almost all high altitude aircraft have long wings (think the U2 as that is not far from what we are talking about here). Adding longer wings typically increases high altitude performance (there are aircraft with model variants where the wings got longer, like the twin commander). This aircraft appears to have borrowed a couple of surfboards.
> I think occam's razor applies here. Either the aerodynamics of reasonably modern aircraft designs leave a huge amount on the table or this startup is telling fibs.
Aerodynamics of reasonably modern aircraft designs do leave a huge amount on the table. Generally for good reasons, though. The 500L is clearly almost entirely a laminar-flow design, unlike conventional aircraft (including the one you linked). Experience from gliders have shown that a small laminar flow design like this can have less than a third of the drag of what a conventionally shaped design of roughly similar size.
There are two major downsides to designing like this:
Firstly, the shape is entirely determined by physics, leaving very little wiggle room for manufacturing or practical concerns. Without modern composites, cost-effectively manufacturing the frame is impractical.
Secondly, the great drag properties are very dependent on the properties of the skin of the aircraft. Laminar-flow gliders can have their glide ratios halved after accumulating a few too many insects on the leading edge. If you want to fly very high, (as this plane seems to want to), better hope you have an amazing de-icing system, or even a very small amount of ice will trash your aerodynamics.
Aerodynamics of reasonably modern aircraft designs do leave a huge amount on the table. Generally for good reasons, though. The 500L is clearly almost entirely a laminar-flow design, unlike conventional aircraft (including the one you linked). Experience from gliders have shown that a small laminar flow design like this can have less than a third of the drag of what a conventionally shaped design of roughly similar size.
There are two major downsides to designing like this:
Firstly, the shape is entirely determined by physics, leaving very little wiggle room for manufacturing or practical concerns. Without modern composites, cost-effectively manufacturing the frame is impractical.
Secondly, the great drag properties are very dependent on the properties of the skin of the aircraft. Laminar-flow gliders can have their glide ratios halved after accumulating a few too many insects on the leading edge. If you want to fly very high, (as this plane seems to want to), better hope you have an amazing de-icing system, or even a very small amount of ice will trash your aerodynamics.
Don't forget low speed handling and stall characteristics.
There are so many places where the practically of this aircraft would fall down. Good luck fitting deicing boots to a wing which needs to be kept so clean polishing it makes a difference.
Also, good luck trying to get an clearence to climb to 60,000ft around any busy international airspace. Regardless of any aerodynamics miracles this aircraft pulls off I'm sure we agree that it's climb performance will be distinctly average. That means it's going to take well over an hour to get up there. 20 mins or more could be spent in the RVSM band (FL280+) where most of the airliners are, expect to be vectored all over the sky while this happens. This is already a problem in something like the CJ2 which like to cruise higher than the airliners but aren't quite as fast. It's climb performance is considerably better than you would expect from this aircraft.
There are so many places where the practically of this aircraft would fall down. Good luck fitting deicing boots to a wing which needs to be kept so clean polishing it makes a difference.
Also, good luck trying to get an clearence to climb to 60,000ft around any busy international airspace. Regardless of any aerodynamics miracles this aircraft pulls off I'm sure we agree that it's climb performance will be distinctly average. That means it's going to take well over an hour to get up there. 20 mins or more could be spent in the RVSM band (FL280+) where most of the airliners are, expect to be vectored all over the sky while this happens. This is already a problem in something like the CJ2 which like to cruise higher than the airliners but aren't quite as fast. It's climb performance is considerably better than you would expect from this aircraft.
I think that the evidence can be really simple (not extraordinary) - just gas it up, fly it for 4500miles in about 11hrs.
Just a nitpick, extraordinary claims normally do not require extraordinary evidence. For example, to gather evidence that, for example, there is a man who could run for 50mph in short bursts, it would require nothing but ordinary evidence. Have a nice day!
I think this airplane is pressurized, flies very high and has a big turbocharger. And it has a diesel engine, so the MPG means a different thing - diesel is denser.
It's optimized differently to the experimentals, and it's more useful commercially. Flying high avoids a lot of weather issues. You don't have to cancel flights because of weather.
The drag from the streamlined shape is very low. It's just a textbook minimum drag shape.
The cruise speed advertised does seem high still.
It's optimized differently to the experimentals, and it's more useful commercially. Flying high avoids a lot of weather issues. You don't have to cancel flights because of weather.
The drag from the streamlined shape is very low. It's just a textbook minimum drag shape.
The cruise speed advertised does seem high still.
All of that helps, but a pilot flying an unpressurized experimental can still get up to 17.5k' VFR on oxygen. Assuming the Celera cruises around FL250, you're talking the difference between ~300KTAS and ~350 KTAS at 200 KIAS. I'd be shocked if they cruise much above FL300, regardless of how high their service ceiling proves to be--for anything other than a really long-distance flight, they'll spend too much time climbing to altitude for it to be worth the effort.
This is optimized for really long distance flight, thousands of miles. That’s the whole point. Cruise height of 30,000ft, I think.
Why would you be shocked by flying at heights comparable to typical jet aircraft flying similar distances?
Why would you be shocked by flying at heights comparable to typical jet aircraft flying similar distances?
I wouldn't be surprised by a long-range cruise altitude around FL300, but if it was FL450 I'd be extremely surprised. If the plane achieves the advertised 20mpg on a hypothetical 4500-mile flight at FL500, but only makes a small fraction of that on a more realistic 400-mile regional hop at FL210, it's not really a practical success.
(Aside: the advertised range seems like drastic overkill for something designed to offer a cheap alternative to private jets--it's difficult to overstate how much it sucks being cooped up in a tiny plane for over 11 hours, even if you have the luxury of rich leather seats, can stand up in the cabin, and don't have to pee into plastic bags. Even if a family wants to charter a private jet from LA to the Bahamas for a long weekend, it'd be miserable trying to one-leg it.)
(Aside: the advertised range seems like drastic overkill for something designed to offer a cheap alternative to private jets--it's difficult to overstate how much it sucks being cooped up in a tiny plane for over 11 hours, even if you have the luxury of rich leather seats, can stand up in the cabin, and don't have to pee into plastic bags. Even if a family wants to charter a private jet from LA to the Bahamas for a long weekend, it'd be miserable trying to one-leg it.)
11 hours in a private plane with lots of room and being able to lay down flat or be in a zero gravity chair would be sheer luxury compared to many flights I've taken. My last long distance flight took 24 hours of travel to get from San Jose to Israel with 3 legs in Coach and going through multiple security gates. One time I flew 16 hours Coach from LA to Guanzhou China and that was a second leg. My tail bone was in pain for a day from sitting that long.
If an airplane like this meant being able to fly private, it's completely worth it. One other factor you have to consider is that this plane can probably use tiny airports which shaves a 4 hours of additional driving and security gates. I'd rather be in a slower flying plane for 7 hours than fly for 4 hours but spend 4 additional hours at security gates and car traffic.
If an airplane like this meant being able to fly private, it's completely worth it. One other factor you have to consider is that this plane can probably use tiny airports which shaves a 4 hours of additional driving and security gates. I'd rather be in a slower flying plane for 7 hours than fly for 4 hours but spend 4 additional hours at security gates and car traffic.
The whole business case for this vehicle is that it enables extremely low cost granular travel between distant city pairs. The short regional hop is not its target market. It’s designed to be competitive with commercial air travel.
That's fair--400 miles is on the shorter end of the spectrum.
Still, "low cost" is relative to a chartered private jet--which, emphatically, is not a service that people purchase because it's the most economical option--rather than a commercial airliner (although, if true, the SFC per passenger of the Celera would be in the same ballpark as modern commercial airliners, which is very impressive). The average domestic flight is under 1000 statute miles (https://www.bts.gov/content/average-length-haul-domestic-fre...), so this plane needs to offer compelling efficiency gains at ~500-1500 mile ranges in order to compete with existing services, unless they're strictly planning to fill the niche of one-leg, long-range flights that existing private jets don't have the legs for.
Still, "low cost" is relative to a chartered private jet--which, emphatically, is not a service that people purchase because it's the most economical option--rather than a commercial airliner (although, if true, the SFC per passenger of the Celera would be in the same ballpark as modern commercial airliners, which is very impressive). The average domestic flight is under 1000 statute miles (https://www.bts.gov/content/average-length-haul-domestic-fre...), so this plane needs to offer compelling efficiency gains at ~500-1500 mile ranges in order to compete with existing services, unless they're strictly planning to fill the niche of one-leg, long-range flights that existing private jets don't have the legs for.
No, they intend to compete with like commercial travel, maybe business class at first, in price per seat per trip to charter an aircraft like this.
$300/hour charter price with 6 seats for a 5 hour trip (2000 miles) is about $250 per seat each way. This is pretty competitive.
$300/hour charter price with 6 seats for a 5 hour trip (2000 miles) is about $250 per seat each way. This is pretty competitive.
$328/hr is the advertised operating cost of the aircraft (fuel and maintenance), not anything close to what a charter would actually charge. Commercial airline operating costs, including crew salary and overhead, are roughly an order of magnitude more (~$3000/hour is a rough, somewhat conservative, number for something like a B737, including fuel, crew, maintenance, and aircraft depreciation/rental costs). The airline is paying under $20 per passenger-hour for all expenses, while a charter service operating with volunteer pilots, free airplanes, and no other costs would break even at ~$55 per passenger-hour (assuming the $328/hr estimate is accurate, which is still very much an open question for an aircraft that's still undergoing initial flight testing and may never be produced in significant volume). Even the best-case scenario doesn't strike me as particularly competitive.
Their patent application implies that it is optimized for cruising at 50,000 feet.
[1]https://patentimages.storage.googleapis.com/3b/f3/9a/928c862...
[1]https://patentimages.storage.googleapis.com/3b/f3/9a/928c862...
I mean, their patent application also claims an SFC of ~30-42 MPG at 460-510 mph...
A design cruising altitude of FL500 implies that they're seeing nearly all of their efficiency improvements due to the thin air at altitude (flying around 200 mph indicated, which isn't totally unreasonable for 20 mpg in a small-ish piston-prop), but I doubt they have the climb rate to actually reach that altitude in anything short of a transcontinental flight.
I like to think they crunched the performance numbers once or twice, but if they're off by the same amount they were with their initial SFC calculations, there's no way they'll reach an acceptable cruising altitude during an average flight.
A design cruising altitude of FL500 implies that they're seeing nearly all of their efficiency improvements due to the thin air at altitude (flying around 200 mph indicated, which isn't totally unreasonable for 20 mpg in a small-ish piston-prop), but I doubt they have the climb rate to actually reach that altitude in anything short of a transcontinental flight.
I like to think they crunched the performance numbers once or twice, but if they're off by the same amount they were with their initial SFC calculations, there's no way they'll reach an acceptable cruising altitude during an average flight.
You don't have to cancel flights because of weather.
I don't think many flights today are cancelled because of weather on the route there, it's the weather over each airport, which would still impact this aircraft.
I don't think many flights today are cancelled because of weather on the route there, it's the weather over each airport, which would still impact this aircraft.
Small unpressurized planes do cancel a lot of flights since they fly lower and are affected by weather.
Many other six seat planes are like that.
Many other six seat planes are like that.
Ahhh.. of course. Good point.
The design of the body reduces drag and acts as a mechanism for lift.
https://en.wikipedia.org/wiki/Lifting_body
https://en.wikipedia.org/wiki/Lifting_body
A lifting body sounds like you are getting something for free, but it does not really work out that way. In terms of efficiency, what matters is the overall lift/drag ratio, and so the first issue is whether shaping the fuselage for lift can be done without creating so much extra drag as to reduce the overall lift/drag ratio. In this regard, note that fuselages are long and narrow, while efficient wings are wide in span and short in chord.
A second factor is the effect of a lifting body on stability, and the cost of compensating for it. Even in the case of nominally non-lifting fuselages, they tend to produce lift at high angles of attack, and that tends to be destabilizing, producing an increasing pitch-up moment as the angle of attack increases (ordinary straight wings do too, but the effect is proportionately less, as the wing chord is considerably less than the fuselage length.) This has to be corrected with measures (typically a larger stablizer) that also create drag. Having a fuselage designed to produce lift exacerbates this problem, commensurably with the amount of lift being generated.
Modern sailplane design is a case study in the persuit of aerodynamic efficiency, at least at low speeds, and lifting bodies have not proved to be useful. The fact is that, once you are flying, you do not need more lift; what you want is less drag.
A second factor is the effect of a lifting body on stability, and the cost of compensating for it. Even in the case of nominally non-lifting fuselages, they tend to produce lift at high angles of attack, and that tends to be destabilizing, producing an increasing pitch-up moment as the angle of attack increases (ordinary straight wings do too, but the effect is proportionately less, as the wing chord is considerably less than the fuselage length.) This has to be corrected with measures (typically a larger stablizer) that also create drag. Having a fuselage designed to produce lift exacerbates this problem, commensurably with the amount of lift being generated.
Modern sailplane design is a case study in the persuit of aerodynamic efficiency, at least at low speeds, and lifting bodies have not proved to be useful. The fact is that, once you are flying, you do not need more lift; what you want is less drag.
While the shape might work well for drag, looks matter, especially with private aviation. This thing just doesn't look very sleek or impressive.
Cost to repair and insurance is also a very significant part of the cost, so if this is difficult to land or costly to repair, it won't be very popular.
Cost to repair and insurance is also a very significant part of the cost, so if this is difficult to land or costly to repair, it won't be very popular.
If it comes even close to the claimed efficiency it could look like a 1961 Skoda and nobody would care
Feel the same, rooting for them but website is still a bit light on actual data and a lot of startup speak, wondering how they would get that big of an improvement vs similarly shaped (Avanti EVO) or powered (DA62) aircraft.
Other question is how safe the simplicity of the shape is, no front wing / canard with presumably very variable CG, or if they’ll have to sacrifice a lot of initial specs to make it work. Also if one should feel comfortable about the only semi-redundant engine over long stretches of water.
Other question is how safe the simplicity of the shape is, no front wing / canard with presumably very variable CG, or if they’ll have to sacrifice a lot of initial specs to make it work. Also if one should feel comfortable about the only semi-redundant engine over long stretches of water.
The CG question is really good, but considering the very conventional tail on the prototype, I imagine it has about the same acceptable CG range as a similar passenger aircraft. The wing just looks like it's way too far back since the engine's in the back instead of the front.
Hopefully it's not intended to do regular transoceanic flights, but it should be fine for shorter crossings (e.g. Great Lakes, Mediterranean north/south, etc.).
Hopefully it's not intended to do regular transoceanic flights, but it should be fine for shorter crossings (e.g. Great Lakes, Mediterranean north/south, etc.).
Well, at least it's clear that they have no competition in piston powered niche because all pressurised piston aircrafts died out. Any remote equivalents are dual engine planes.
Piper would like to please remind you that it is still selling the PA-46 Malibu / Mirage / M350 pressurized piston single.
Has anyone asked Rutan what he thinks about the Celera?
My RV-7 gets ~25 mpg depending on winds, power settings, etc. It’s been done before in private aviation. But, this is a very interesting design. Like you said, aviation does have a long history of new designs making big claims that don’t pan out in reality. I wonder what tradeoffs they made to achieve those results. It’s encouraging they’re into test flying phase, though.
Stands to reason that a modified glider will achieve the best efficiency characteristics. That is after all, practically speaking, the raison d'ètre for sailplanes.
[deleted]
It's a Diesel. The engine is made by RED in Germany.[1] Almost the same Diesel powers the YAK-152 trainer.[2] Celera avoids the term "Diesel", but that's what it is. It runs on Diesel fuel, or JET-A, which is much the same thing.
The base engine has been flying for several years. This is the turbocharged model. So it's an engine design with some flight experience.
[1] https://red-aircraft.com/
[2] https://en.wikipedia.org/wiki/Yakovlev_Yak-152
The base engine has been flying for several years. This is the turbocharged model. So it's an engine design with some flight experience.
[1] https://red-aircraft.com/
[2] https://en.wikipedia.org/wiki/Yakovlev_Yak-152
Interesting trivia: the CTO of RED and part of the staff used to work for and build Toyota F1 engines in Cologne.
Ok, but so what? Is there something bad about diesel engines?
Nothing is inherently bad but diesels tend to be heavier for the power they make. And there's a fairly well understood weight vs reliability tradeoff. Light an unreliable is bad for airplanes and so is heavy and reliable. You want light and reliable, ideally.
It is a V12. Historical military V12s had a feature of two bank redundancy. One row of 6 cylinders can be shut down along with its pumps, cooling, etc.
And I have a big suspicion that they use two of these engines inside.
And I have a big suspicion that they use two of these engines inside.
V* engines share a common crankshaft with both banks, that's the V part. Please cite any specific V12 aircraft engine that can have one bank of cylinders shut down. I don't believe one exists.
Most V engines can operate this way -- obviously not at full power. GM, Daimler, Honda, and FCA do this on some of their production v6, v8, and v12 engines. It is not that difficult to skip some cylinders, engines have a lot of rotating momentum.
https://en.wikipedia.org/wiki/Multi-Displacement_System
https://en.wikipedia.org/wiki/Active_Fuel_Management
https://en.wikipedia.org/wiki/Active_Cylinder_Control
https://en.wikipedia.org/wiki/Variable_Cylinder_Management
https://en.wikipedia.org/wiki/Multi-Displacement_System
https://en.wikipedia.org/wiki/Active_Fuel_Management
https://en.wikipedia.org/wiki/Active_Cylinder_Control
https://en.wikipedia.org/wiki/Variable_Cylinder_Management
There is a huge difference between being able to operate in a managed cylinder deactivation mode vs being able to operate when one whole bank is experiencing some kind of catastrophic failure.
True, I was addressing the question at face value.
Of course the crankshaft is shared. It is oil, fuel, and cooling that can be shut down to prevent leaks.
I don't know much about aircraft engines, but in fact straight-6 engines are inherently balanced, and a V12 is fundamentally two straight sixes, so at least in theory it would be quite possible to stop using one bank of cylinders if some of their cylinders suffered some form of non-catastrophic failure.
Although I can't find a reference to an aircraft engine, Chrysler did have a variable displacement tech on its third gen Hemi engines that could turn off one bank of the V8.
Ref: https://en.wikipedia.org/wiki/Multi-Displacement_System
Ref: https://en.wikipedia.org/wiki/Multi-Displacement_System
>Please cite any specific V12 aircraft engine that can have one bank of cylinders shut down.
The RED A03 Engine[0], which is what this sub-thread is about.
>Two cylinder-bank redundancy concept for high safety.
>Robustness and safety are incorporated into the engine design. The two 6-cylinder banks are capable of independent operation. All critical engine sub-systems are mutually-independent.
[0] https://red-aircraft.com/
The RED A03 Engine[0], which is what this sub-thread is about.
>Two cylinder-bank redundancy concept for high safety.
>Robustness and safety are incorporated into the engine design. The two 6-cylinder banks are capable of independent operation. All critical engine sub-systems are mutually-independent.
[0] https://red-aircraft.com/
Except the crankshaft...
Oh, and any mechanical issues with pistons or valves in one side will jam the crankshaft, therefore stop the other half working...
And that crankshaft needs some kind of oil... And a pump to pressurize that oil. And if a leak forms anywhere the oil drains out and the crankshaft seizes. Pretty hard to lube one crankshaft with two redundant and isolated oil systems...
Overall, I'd call the engine 1.5x redundancy...
Oh, and any mechanical issues with pistons or valves in one side will jam the crankshaft, therefore stop the other half working...
And that crankshaft needs some kind of oil... And a pump to pressurize that oil. And if a leak forms anywhere the oil drains out and the crankshaft seizes. Pretty hard to lube one crankshaft with two redundant and isolated oil systems...
Overall, I'd call the engine 1.5x redundancy...
Agreed. Based on the documents, I also don't see any protection against metorites or the sudden loss of oxygen in the planet's atmosphere. That's not even 1x redundancy really.
This is far lighter and significantly different from your usual diesel, though. It's an all-aluminum design and weighs 250-300kg. Heavier (for the same power) than competing turbine engines (like, say, the ubiquitous PT6?) Sure, absolutely. Crazy heavy? Nah. The entire thing probably weighs somewhere around 2000-3000kg (veeery roughly) if I had to guess. So the extra 100kg or so isn't a total dealbreaker, if they can make it up elsewhere.
Very interesting aircraft for sure. I'm still skeptical, but hoping it works out, and rooting for them!
Some discussion on its claims to fly at 65,000 feet here: https://www.beechtalk.com/forums/viewtopic.php?f=49&t=174467...
Very interesting aircraft for sure. I'm still skeptical, but hoping it works out, and rooting for them!
Some discussion on its claims to fly at 65,000 feet here: https://www.beechtalk.com/forums/viewtopic.php?f=49&t=174467...
Not at all, without question it's a superior fuel to leaded avgas.
It has higher energy density, higher flash point (less prone to fire or explosion), less volatile (doesn't evaporate as quickly), and less toxic.
However, it's difficult to make a diesel that gets as much power/weight or power/volume as a comparable petrol engine.
There are trade-offs. It's not a universally superior fuel.
However, it's difficult to make a diesel that gets as much power/weight or power/volume as a comparable petrol engine.
There are trade-offs. It's not a universally superior fuel.
They weigh more but have lower fuel consumption. More complex than gasoline aero engines. Usually more reliable but making them light probably impacts that. I think the lower fuel consumption compensates for the higher weight for longer flights.
Big reason for switching to them after 100 years of using gasoline is aviation gas is expensive and concerns about lead. Big picture I think refineries and distributors don't want to supply aviation gasoline anymore.
Big reason for switching to them after 100 years of using gasoline is aviation gas is expensive and concerns about lead. Big picture I think refineries and distributors don't want to supply aviation gasoline anymore.
BSFC as in horsepower generated per unit of fuel tends to be better in Diesel engines, but they’re heavier because the combustion events are more violent, requiring a stronger block and pistons.
[deleted]
It seems to require a pretty seriously long runway to take off. On a warm day, we’re talking international airport length runway.
While pistons are cheaper than turbines, that’s because almost all of the approved pistons on the market use 1940s or earlier technology. They are very, very, very simple machines. They are still extremely expensive.
This engine is very complicated, even for an automotive engine. It’s got some revolutionary attributes, but it also has a bunch of single points of failure that would mean traveling in this airplane over long distances and large bodies of water isn’t a good idea.
I’m frankly not holding my breath. While they’ve got a bunch of buzz around them, that and a working example are like 1/10 the battle in the aircraft industry. Wish them the best for trying to advance the art but many more established and better funded folks have tried and gone bankrupt before them.
While pistons are cheaper than turbines, that’s because almost all of the approved pistons on the market use 1940s or earlier technology. They are very, very, very simple machines. They are still extremely expensive.
This engine is very complicated, even for an automotive engine. It’s got some revolutionary attributes, but it also has a bunch of single points of failure that would mean traveling in this airplane over long distances and large bodies of water isn’t a good idea.
I’m frankly not holding my breath. While they’ve got a bunch of buzz around them, that and a working example are like 1/10 the battle in the aircraft industry. Wish them the best for trying to advance the art but many more established and better funded folks have tried and gone bankrupt before them.
3,300 feet in not a long runway - it means you can access ~80% of the ~5,000 runways in the US. On the the other hand A 777 needs 8,000-10,000 feet meaning it can only access <10% of US runways....
https://www.cia.gov/library/publications/the-world-factbook/...
https://en.wikipedia.org/wiki/Boeing_777#777-200LR
https://www.cia.gov/library/publications/the-world-factbook/...
https://en.wikipedia.org/wiki/Boeing_777#777-200LR
Also, a 3300' take-off roll doesn't mean you need a 3300' runway to operate--if you lose the engine just before rotation speed, you might need a few thousand more feet to stop the aircraft.
3300 feet in balanced density conditions. You’d better not bet on 3300 feet in Phoenix during the day time most of the year. Or Denver for that matter.
Sorry for the amateur question, but why does it take longer to take off in hot places? Doesn’t heat generate lift, like in gliders crossing hilly terrain? Or is it the heat offsetting with the cooler ground that helps, so you’d need a greater amount in hot places?
It has to do with air density.
Heavy, cold air will generate more lift since it's "thicker" for lack of a better term.
Hot air is less dense. This means it takes more power to move more air.
It's easier to maybe think of the air that you breath as a "liquid" like material comprised of a mix of mostly nitrogen, some oxygen and a little carbon dioxide and other gases. That mix changes with temperature and elevation. Just like the deeper under the ocean that you go, you have more pressure, the lower to the ground you are the more atmospheric pressure you will feel. And the higher that you go, there's less pressure.
Heavy, cold air will generate more lift since it's "thicker" for lack of a better term.
Hot air is less dense. This means it takes more power to move more air.
It's easier to maybe think of the air that you breath as a "liquid" like material comprised of a mix of mostly nitrogen, some oxygen and a little carbon dioxide and other gases. That mix changes with temperature and elevation. Just like the deeper under the ocean that you go, you have more pressure, the lower to the ground you are the more atmospheric pressure you will feel. And the higher that you go, there's less pressure.
A different way to think about it is the Newtonian approach: your wing is accelerating air particles in a downward direction, and the equal-and-opposite reaction is what (partially) generates the lift on the aircraft. Lower density means there’s fewer particles to deflect downwards in a given volume of air. In a similar vein, a rotation of the propellor accelerates air particles rearward, which results in a forward thrust on the aircraft; fewer particles to accelerate means less thrust.
> why does it take longer to take off in hot places?
When the air is cold the air is more dense. This has an impact both on how much lift is generated per amount of speed over the wings, and also impacts how much power the engine/carburetor are able to generate.
When the air is cold the air is more dense. This has an impact both on how much lift is generated per amount of speed over the wings, and also impacts how much power the engine/carburetor are able to generate.
When it is hot out Air is less dense so the wings don’t generate as much lift.
I believe engines make less power when the air in is hotter too as there is less delta T. Something something Carnot cycle
I believe engines make less power when the air in is hotter too as there is less delta T. Something something Carnot cycle
The Carnot efficiency does drop as T_c increases, so all else being equal, for the same amount of fuel being burned, you'll get less energy. However, more importantly, at higher temperatures, a given volume of air at the same pressure contains less oxygen. All else being equal, at higher ambient temperatures, you're burning less fuel. For a turbocharged engine, you could increase boost to counter-act the reduced density, but that increases both mechanical and thermal stresses within the engine.
Anyway, I think the reduction of oxygen density is the primary driver for reduction in power as ambient temperatures rise.
Anyway, I think the reduction of oxygen density is the primary driver for reduction in power as ambient temperatures rise.
The engine indeed makes less power, but since the air density is lower, you also have much less drag. (I know that for cars, the drag reduction dominates the power efficiency).
For airplanes take-off, the lift is the issue I'd say.
For airplanes take-off, the lift is the issue I'd say.
As a concrete example, current Formula 1 cars reach their fastest speed at the Mexico Grand Prix, held at Autódromo Hermanos Rodríguez in Mexico City. Current race record is 372.5km/h (231.5 mph)[1].
The elevation of the track is around 2200m, and as you say the loss of drag more than compensates for the loss of engine power. Though being turbo engines helps as I understand.
[1]: https://en.wikipedia.org/wiki/List_of_Formula_One_race_recor...
The elevation of the track is around 2200m, and as you say the loss of drag more than compensates for the loss of engine power. Though being turbo engines helps as I understand.
[1]: https://en.wikipedia.org/wiki/List_of_Formula_One_race_recor...
Yep it's lift and for some planes power loss due to less oxygen in the engine, but that highly depends on the kind of engine. You do get faster easier due to less drag but you also need to be faster until you have enough lift to take off. So maybe the takeoff run won't take that much longer, but you'll have covered a lot more distance.
The effect operating on gliders is from thermals - warmer ground heats the air which then rises relative to the cooler air around it. When the glider is in the thermal, it is still gliding downward through that air, but the whole column is rising faster than the glider's sink rate.
Warmer air reduces density, thus reducing lift and slightly reducing the amount of oxygen reaching the engine's combustion area, thus some power loss as well. In order to take off in the same distance, it must be operating at reduced takeoff weight.
Warmer air reduces density, thus reducing lift and slightly reducing the amount of oxygen reaching the engine's combustion area, thus some power loss as well. In order to take off in the same distance, it must be operating at reduced takeoff weight.
Other answers already address the engine performance loss and lift loss, but about that:
> Doesn’t heat generate lift, like in gliders crossing hilly terrain?
That lift is generated by a temperature difference, not a globally high temperature. Thermals used by gliders are thermals because the air is locally hotter than the environment. If the whole environment gets warm, you don't get thermals.
> Doesn’t heat generate lift, like in gliders crossing hilly terrain?
That lift is generated by a temperature difference, not a globally high temperature. Thermals used by gliders are thermals because the air is locally hotter than the environment. If the whole environment gets warm, you don't get thermals.
The term you're looking for is "density altitude".
hot air rises but its less dense thats why it rises, so it has less lifting capacity thermal updrafts are different they are a larger scale phenomenon
This is a tangent, but are runways generally longer in hotter areas? Is, for example, the median length of all runways in Arizona longer than the median in North Dakota?
It seems like ideally this is the way it should be because it's a known factor, so they ought to just build in compensate for it / normalize around it from the start. But I could imagine things standing in the way of that, like cost or land availability or maybe people focus more on meeting some minimum standard length.
It seems like ideally this is the way it should be because it's a known factor, so they ought to just build in compensate for it / normalize around it from the start. But I could imagine things standing in the way of that, like cost or land availability or maybe people focus more on meeting some minimum standard length.
Aspen seems like a likely destination for this kind of craft. Is an 8000' runway at 9000' of elevation sufficient?
The article says its typical takeoff run is 3300 feet, which is about half what a 737 needs. I don’t know a lot about airplanes, but that seems like a pretty short runway length requirement. What am I missing?
The 737 is a far larger plane. The Celera has capacity for 6 passengers, while you can cram over 200 into a 737.
For a better comparison, the world's most popular aircraft, the four-seater Cessna 172, needs under 500 feet to take off in optimal conditions, although you might need 1500 feet if fully loaded and high up.
http://www.dmjwilliams.co.uk/gbsep_performance.htm (in meters, not feet)
However, the Cessna Citation M2 business jet, which targets a similar market as the Celera, also requires ~3000 ft (again depending on weight, altitude, conditions). So not seeing a huge difference here.
https://prijet.com/performance/Cessna%20Citation%20M2
For a better comparison, the world's most popular aircraft, the four-seater Cessna 172, needs under 500 feet to take off in optimal conditions, although you might need 1500 feet if fully loaded and high up.
http://www.dmjwilliams.co.uk/gbsep_performance.htm (in meters, not feet)
However, the Cessna Citation M2 business jet, which targets a similar market as the Celera, also requires ~3000 ft (again depending on weight, altitude, conditions). So not seeing a huge difference here.
https://prijet.com/performance/Cessna%20Citation%20M2
Takeoff run length is for the marketing sheets.
What counts is the ASD — accelerate-stop distance, see also, balanced field length.
Citation, https://en.wikipedia.org/wiki/Balanced_field_takeoff?wprov=s...
/Acey
What counts is the ASD — accelerate-stop distance, see also, balanced field length.
Citation, https://en.wikipedia.org/wiki/Balanced_field_takeoff?wprov=s...
/Acey
A typical small airport might have a 2,500-foot runway, and you never want to come anywhere close to using all that up. It's often desirable to use small airports that are closer to your origin and destination, which could save several hours of travel time before takeoff and after landing. Usually there's also less air traffic to contend with, no landing fees, and cheaper aircraft parking.
3300 feet = 1 km
(for people outside US)
I would bet they end up putting liquid cooled electric motors in the wheels to shorten the take off distance to 1500 feet.
With a supposedly 10x improvement in an important metric (fuel consumption, together with reasonable speed and carrying enough fuel for range), there must surely be a big idea driving the change. Something that stands out.
I can't quite follow what specifically makes this aircraft special. I mean, it's an odd shape, and it has a piston engine. But what's driving the huge improvements? Improvements in CFD software driving aerodynamic design? Automotive technology bringing engine efficiencies? Some trade-off of stability that has previously been avoided but new avionics have overcome? The comparisons are all against business jets - is it in some way a well-designed propeller aircraft sitting in the space where the utility of jets versus propeller craft starts to cross over and small jets become inefficient?
I suppose it's not impossible that it sits in an unexplored area of the design space - a clever designer starting from a clean sheet of paper and ending up with something that works really well. But it would be extremely unusual after a century-plus of innovation. I don't like that breathless articles are written about this plane without any attempt to describe what the special sauce may be.
I can't quite follow what specifically makes this aircraft special. I mean, it's an odd shape, and it has a piston engine. But what's driving the huge improvements? Improvements in CFD software driving aerodynamic design? Automotive technology bringing engine efficiencies? Some trade-off of stability that has previously been avoided but new avionics have overcome? The comparisons are all against business jets - is it in some way a well-designed propeller aircraft sitting in the space where the utility of jets versus propeller craft starts to cross over and small jets become inefficient?
I suppose it's not impossible that it sits in an unexplored area of the design space - a clever designer starting from a clean sheet of paper and ending up with something that works really well. But it would be extremely unusual after a century-plus of innovation. I don't like that breathless articles are written about this plane without any attempt to describe what the special sauce may be.
> had a maximum cruising speed of at least 450 miles per hour and a range of over 4,500 miles
Given the shape of the airplane, I'd guess the 4,500 miles range is not at 450 miles per hour, but much much less. Also, it needs to fly very high, so you need to correct the time it takes to travel with this with the longer take off and landing times.
It wouldn't surprise me if the "effective" velocity of this plane for long distances was more like 200 mph. I hope I'm wrong.
Given the shape of the airplane, I'd guess the 4,500 miles range is not at 450 miles per hour, but much much less. Also, it needs to fly very high, so you need to correct the time it takes to travel with this with the longer take off and landing times.
It wouldn't surprise me if the "effective" velocity of this plane for long distances was more like 200 mph. I hope I'm wrong.
It seems a bit dishonest to compare it to a jet, when the obvious competition is a single engine Turboprop like a TBM or PC-12.
On paper it beats those aircraft, but by a far less impressive margin when you consider engine TBO, which is currently 1250 hrs on the EASA cert. With the inherent unreliablilty of piston engines, a PT-6 might look more appealing.
I'd love to see this aircraft come to market, but I fear it may go the way of many innovative aircraft; the company underestimated the cost and complexity or certification and goes bankrupt.
On paper it beats those aircraft, but by a far less impressive margin when you consider engine TBO, which is currently 1250 hrs on the EASA cert. With the inherent unreliablilty of piston engines, a PT-6 might look more appealing.
I'd love to see this aircraft come to market, but I fear it may go the way of many innovative aircraft; the company underestimated the cost and complexity or certification and goes bankrupt.
Big guesstion, do they have one, or two engines? A combiner gearbox does not fare well in aviation, as history show.
I have a hard time believing they can get to such speed with just 500hp.
I have a hard time believing they can get to such speed with just 500hp.
That advertised speed seems to be ground speed, the trick is that they designed this thing to fly very high where the corresponding IAS is much lower. What's new (and a truly surprising as impressive technological achievement!) is that they do this on a piston engine which are notoriously less capable at high altitudes than jets or turboprops.
An implication of this is that short-haul applications will see neither the speed more the mileage advertised. I still want to see the general design principles applied to the problem of regional feeder flights, it won't be quite as over the top impressive but it would still be the closest to "slow steaming" available
(speed really doesn't matter on feeder connections where boarding alone takes longer than the flight, but it's very hard for aircraft to trade speed for efficiency once non-negligible payloads are involved)
An implication of this is that short-haul applications will see neither the speed more the mileage advertised. I still want to see the general design principles applied to the problem of regional feeder flights, it won't be quite as over the top impressive but it would still be the closest to "slow steaming" available
(speed really doesn't matter on feeder connections where boarding alone takes longer than the flight, but it's very hard for aircraft to trade speed for efficiency once non-negligible payloads are involved)
One engine, a turbocharged V-12.
which pretty much keeps it restricted to overland only. it took a long time for the FAA to permit twins to fly across the ocean? ETOPS (Extended-Range Twin Engine Operational Performance Standards) is just what it says, twin engine but is there any possible means a passenger carrying single engine could get certification? Now as an unmanned cargo drone it might get this permission.
You can fly a single over the ocean, you just have to carry extra equipment.
And as others have mentioned, it's taken advantage of newer technology that allows six of pistons to be turned off.
The engine basically sounds like two in-line six cylinder engines that share many common single engine features but with the ability to shut off one side and use power from the remaining side.
So hypothetically, you fly up to altitude and climb using all 12 cylinders, then cruise on six.
That could be where the fuel efficiency is being notched up versus burning all 12 cylinders at all times.
Kinda like how people are still amazed variable displacement engines took them from 10mpg to 18-20mpg. It's also likely the engine has a number of other more recent innovations included too. Variable valve timing, etc, etc. A lot of new rather exciting new engine technology has come out in the last 20 years.
It's much like when we went from naturally aspirated aka carbs to electronic fuel injection/ignition.
The engine basically sounds like two in-line six cylinder engines that share many common single engine features but with the ability to shut off one side and use power from the remaining side.
So hypothetically, you fly up to altitude and climb using all 12 cylinders, then cruise on six.
That could be where the fuel efficiency is being notched up versus burning all 12 cylinders at all times.
Kinda like how people are still amazed variable displacement engines took them from 10mpg to 18-20mpg. It's also likely the engine has a number of other more recent innovations included too. Variable valve timing, etc, etc. A lot of new rather exciting new engine technology has come out in the last 20 years.
It's much like when we went from naturally aspirated aka carbs to electronic fuel injection/ignition.
Naturally aspirated != carb.
You can have a naturally aspirated engine with electronic (even direct) injection, or a turbocharged engine with a carburetor, or any other combination.
You can have a naturally aspirated engine with electronic (even direct) injection, or a turbocharged engine with a carburetor, or any other combination.
True. Naturally aspirated simply refers to the lack of a turbocharger/supercharger pressurizing atmospheric air as "boost".
I just wish carbureted was an easier word to spell after not using it for months at time.
I just wish carbureted was an easier word to spell after not using it for months at time.
Or compare it to a single engine very light jet like the cirrus visionjet.
The revolutionary part is to use V12 turbo-diesel piston engine for high cruise altitude instead of turboprop or jet engine.
Aerospace experts are skeptical https://www.thedailybeast.com/this-weird-plane-could-be-the-...
>Juan Alonso, a professor in the Department of Aeronautics at Stanford University, has his doubts. A 30 percent improvement in fuel-efficiency is possible in an airplane with a new, more aerodynamic wing design, an ultra-light airframe made from high-tech composite materials and a super-efficient engine.
>But an 800 percent improvement? “Unlikely,” Alonso told The Daily Beast. The Celera 500L’s rear-mounted propeller is a good choice for a more fuel-efficient plane, Alonso said. But the egg-like fuselage probably is less fuel-efficient than the narrower fuselages on planes such as the PC-12, he pointed out.
>Mark Drela, an MIT aeronautical engineer, is equally skeptical. “The 500L looks fairly well-designed,” Drela told The Daily Beast, “but I cannot say whether it’s close to optimum, or whether the diesel engine makes sense.”
> To say for sure, Drela said he’d need to know how much the Celera 500L weighs and how efficient its engine is. Since Otto isn’t talking, Drela can only guess. And he’s guessing that the Celera 500L isn’t nearly as efficient as Otto hopes it will be.
Aerospace experts are skeptical https://www.thedailybeast.com/this-weird-plane-could-be-the-...
>Juan Alonso, a professor in the Department of Aeronautics at Stanford University, has his doubts. A 30 percent improvement in fuel-efficiency is possible in an airplane with a new, more aerodynamic wing design, an ultra-light airframe made from high-tech composite materials and a super-efficient engine.
>But an 800 percent improvement? “Unlikely,” Alonso told The Daily Beast. The Celera 500L’s rear-mounted propeller is a good choice for a more fuel-efficient plane, Alonso said. But the egg-like fuselage probably is less fuel-efficient than the narrower fuselages on planes such as the PC-12, he pointed out.
>Mark Drela, an MIT aeronautical engineer, is equally skeptical. “The 500L looks fairly well-designed,” Drela told The Daily Beast, “but I cannot say whether it’s close to optimum, or whether the diesel engine makes sense.”
> To say for sure, Drela said he’d need to know how much the Celera 500L weighs and how efficient its engine is. Since Otto isn’t talking, Drela can only guess. And he’s guessing that the Celera 500L isn’t nearly as efficient as Otto hopes it will be.
Large parts of this article read as though they were lazily & uncritically copied straight out of a press release.
It does sound a bit too good to be true. But I’d love it to be true!
It sounds like a pretty seriously amazing plane. Even allowing for a positive spin this seems like a pretty big deal for the market it's in.
Yeah it's pretty breathless.
It's still a GA aircraft though... so you still have to deal with all the BS. If you don't own it yourself then you need to pay a pilot (though with the recent downturn there's no shortage of pilots). There is absolutely no way many people will try and get their pilot's license. The FAA written test for a PPL may be easy compared to IR but it's still not a walk in the park. The checkrides are very strict nowadays too.
So if you're paying a pilot, FBO costs (or dealing with a commercial operator of the planes), etc. at the end of the day it's never going to be as cheap as commercial airlines. This certainly would make it affordable. But not that affordable.
So if you're paying a pilot, FBO costs (or dealing with a commercial operator of the planes), etc. at the end of the day it's never going to be as cheap as commercial airlines. This certainly would make it affordable. But not that affordable.
That said, it would definitely be cheaper to certify a pilot on this than on a business jet, since the flight hours for the aircraft cost much less.
Ehhh usually type ratings aren't the most expensive part of training though. Plus on larger business jets there are simulators that are used in lieu of in-aircraft time for most of the training.
You're still looking at bare minimum a CPL with instrument rating which is minimum 250 hours (realistically 350 or so). Probably more than that before any insurance company is OK with you flying it single pilot.
You're still looking at bare minimum a CPL with instrument rating which is minimum 250 hours (realistically 350 or so). Probably more than that before any insurance company is OK with you flying it single pilot.
If I had to guess, the certification and training process on this would best be compared to advanced single engine expensive aircraft like a Pilatus PC-12. Or a Cessna Caravan. Anything else out there in the single engine turboprop PT6 (or competing engine) category.
I think the point is more that this kind of tech could be scaled up to make commercial airliners more fuel efficient too?
From https://www.ottoaviation.com/technology
"The design of the Celera fuselage takes advantage of an optimum length-to-width ratio to maximize laminar flow. These benefits will not scale for large jet transports and are therefore well suited for an aircraft like the Celera."
"The design of the Celera fuselage takes advantage of an optimum length-to-width ratio to maximize laminar flow. These benefits will not scale for large jet transports and are therefore well suited for an aircraft like the Celera."
A big part of the "tech" is the engine and its turbocharger. That doesn't really scale.
Is there automated flying on the horizon? Seems to me that it should be a lot simpler than for cars and would make operating so much simpler and more cost effective.
I used to think totally automated flight was possible before I started getting my pilot's license. Now I doubt we'll even see it in the next 50 years. The national airspsace system relies on interactions with other pilots and unless all planes became automated it would be really hard to pull it off.
For starters, flying is the easy part. It's the fuel management, dealing with communications to ensure aircraft are safe, and reacting to constantly changing weather that gets tricky. When there's an emergency things get even more complicated since electrical malfunctions are definitely a not so uncommon possibility. For anything safety critical you're going to need 2-3 way redundancy.
Plus you'd need some kind of standardized aircraft to aircraft data link on all aircraft.
For starters, flying is the easy part. It's the fuel management, dealing with communications to ensure aircraft are safe, and reacting to constantly changing weather that gets tricky. When there's an emergency things get even more complicated since electrical malfunctions are definitely a not so uncommon possibility. For anything safety critical you're going to need 2-3 way redundancy.
Plus you'd need some kind of standardized aircraft to aircraft data link on all aircraft.
Unlikely. The automatable parts are basically all automated already (autopilot, take-off, landing). Making an aerial robot take off from runway X and land at Y in clear skies with a well-maintained machine is solved.
Human pilots, in addition to piloting, do a bazillion small things which add up to a safe flight, such as tons of systems checks. Often, e.g. under autopilot, their job is to act as fallback when the automated systems fail. When the automated checks fail to catch issues in other automated systems, the buck stops with the captain. Or maybe it's an important radio call. Even if you patch the uav into a pilot in a sim, there's so much situational awareness lost.
I don't see it happening any time soon in the commercial space.
Human pilots, in addition to piloting, do a bazillion small things which add up to a safe flight, such as tons of systems checks. Often, e.g. under autopilot, their job is to act as fallback when the automated systems fail. When the automated checks fail to catch issues in other automated systems, the buck stops with the captain. Or maybe it's an important radio call. Even if you patch the uav into a pilot in a sim, there's so much situational awareness lost.
I don't see it happening any time soon in the commercial space.
The fuel mileage sounds incredible, it's in the same range as an F150. The pilot must be a major part of the expense, meaning it could also be well positioned for an autonomous shuttle future, if those are ever fully trusted, bringing the cost down even further.
Obviously they still have a long way to but they are saying the right things to get me excited, even though my knowledge of aircraft efficiency is pretty minimal.
edit: It looks like the Yak-152 mentioned elsewhere in the thread can do about 14 mpg if wikipedia & my math is right.
Obviously they still have a long way to but they are saying the right things to get me excited, even though my knowledge of aircraft efficiency is pretty minimal.
edit: It looks like the Yak-152 mentioned elsewhere in the thread can do about 14 mpg if wikipedia & my math is right.
> It looks like the Yak-152 mentioned elsewhere in the thread can do about 14 mpg if wikipedia & my math is right.
Isn't the MPG highly dependent on what it's paired with? You can't expect a Honda Civic to hit it's stated MPG either if you overload the car or tow something, but if you replace a lot of parts with lighter equivalents (or put the engine in a lighter car) you would expect it to get a higher MPG.
One of the major points of this plane is that it's supposed to be extremely aerodynamic.
Isn't the MPG highly dependent on what it's paired with? You can't expect a Honda Civic to hit it's stated MPG either if you overload the car or tow something, but if you replace a lot of parts with lighter equivalents (or put the engine in a lighter car) you would expect it to get a higher MPG.
One of the major points of this plane is that it's supposed to be extremely aerodynamic.
Not gonna lie, this week I've read two HN postings about dope planes for rich people (boom, now this)......and news articles detailing a crisis of austerity for the NYC subway.
It's really sad to me that we can VC these wild bets on inefficient transport for the few, meanwhile perhaps the most efficient people-mover ever devised for the many is on an entirely politically-caused death bed.
It's really sad to me that we can VC these wild bets on inefficient transport for the few, meanwhile perhaps the most efficient people-mover ever devised for the many is on an entirely politically-caused death bed.
NYC is a very rich city. NYC can definitely afford a better subway.
People come to the voting stations and pick the candidate with the most important agenda for them. Obviously, the NYC subway does not seem to be the largest issue.
If you want to blame rich people for that, well, welcome to the USSR.
People come to the voting stations and pick the candidate with the most important agenda for them. Obviously, the NYC subway does not seem to be the largest issue.
If you want to blame rich people for that, well, welcome to the USSR.
The subway that benefits the city is controlled by the state of New York. The state of New York that would like to spend counter-cyclically is constrained by laws and the inability to issue currency, and thus has a budget that is controlled by the feds.
At every level, the political power is structured poorly to make the subway (and regional infra in general) a low priority.
At every level, the political power is structured poorly to make the subway (and regional infra in general) a low priority.
If the design works there's no reason it shouldn't work on a A320/B737 size. But without a small prototype, the billions for developing a completely new plane and engine are not worth it.
I'm sure Airbus & Boeing are following this closely. A large turboprop (even at sizes of a A220) would further reduce ticket costs for budget airlines.
I'm sure Airbus & Boeing are following this closely. A large turboprop (even at sizes of a A220) would further reduce ticket costs for budget airlines.
Privatize it and it will improve dramatically in a very short time.
Bill Lear did it first:
https://en.wikipedia.org/wiki/LearAvia_Lear_Fan
Success is dependent on the gearbox.
Success is dependent on the gearbox.
> Success is dependent on the gearbox.
This uses a single V12 Diesel engine. The Lear Fan used dual turboshaft engines.
This uses a single V12 Diesel engine. The Lear Fan used dual turboshaft engines.
It is not clear yet: https://the-drive.imgix.net/https%3A%2F%2Fs3-us-west-2.amazo...
And the speed figures are hard to believe for just 500hp, and an aircraft of this size.
What is on the photo make me think they have 2 of them, mounted at 120 degrees.
And the speed figures are hard to believe for just 500hp, and an aircraft of this size.
What is on the photo make me think they have 2 of them, mounted at 120 degrees.
It is in fact registered as a single-engine[1], but I am also suspicious. There is wiggle-room in a twin with single drive train.
If the engine were also turbo/supercharged and could do closer to 1000shp, might be possible. But if really only 500hp I think it's more 450 mph with a single pilot and no load at 45K. Same with range and field length.
[1] https://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?N...
If the engine were also turbo/supercharged and could do closer to 1000shp, might be possible. But if really only 500hp I think it's more 450 mph with a single pilot and no load at 45K. Same with range and field length.
[1] https://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?N...
Ahh, that makes much more sense. Upvoted.
All of this is lifted from from https://www.ottoaviation.com/ which seems geared for investors.
Another point that doesn't get mentioned in the article is noise. Laminar flow with a 59% reduction would make the aircraft much quieter, especially during approach. Aerodynamic drag is the primary source of landing planes, reducing that can greatly help communities around airports and avoid curfews.
But planes need that to decelerate / reduce both kinetic and gravitational potential energy though, don't they? I suppose air should always be able to do that even at higher efficiency.
You don't see a lot of pusher-configuration aircraft. I wonder if they plan on using the same design for a military UAV?
Having a multi-fuel capable engine is a pretty clever design choice, and I imagine the improved aerodynamics come from the combination of the pusher configuration and the lack of windows (the latter enables a lighter, stronger, and more streamlined fuselage).
Fuel consumption looks to be about double a Cessna 182 (18-25 gal/hour), but that's rather good for an aircraft of this type.
One question did spring to mind: why have they styled it after a vibrator?
Having a multi-fuel capable engine is a pretty clever design choice, and I imagine the improved aerodynamics come from the combination of the pusher configuration and the lack of windows (the latter enables a lighter, stronger, and more streamlined fuselage).
Fuel consumption looks to be about double a Cessna 182 (18-25 gal/hour), but that's rather good for an aircraft of this type.
One question did spring to mind: why have they styled it after a vibrator?
> One question did spring to mind: why have they styled it after a vibrator?
“It’s all about the laminar flow”[0]
[0] https://www.ottoaviation.com/technology
“It’s all about the laminar flow”[0]
[0] https://www.ottoaviation.com/technology
I was reminded of those water pressure rocket toys: https://thumbs.worthpoint.com/zoom/images1/1/0812/07/parks-p...
> I wonder if they plan on using the same design for a military UAV?
A mockup of a UAV version is shown in the article.
A mockup of a UAV version is shown in the article.
it is much faster than a C182. if it flew at Cessna speeds it might be about even
> This and aircraft's other notable performance characteristics are made possible in large part due to its highly aerodynamic overall laminar flow shape, which produces approximately 59 percent less drag than existing similar-sized, more conventionally-shaped aircraft.
Wait, if the shape is that much more efficient, why don't we already see this sort of shape for commercial jets? Are there other compromises involved?
Wait, if the shape is that much more efficient, why don't we already see this sort of shape for commercial jets? Are there other compromises involved?
I'm kind of curious as to why they went with the engine that they did instead of something based off of Chevrolet's LS engine architecture, but tuned for the unique demands of planes. Seems that they place efficiency as a high standard, and the LS series of engines are pretty efficient in terms of how much power they generate vs how much space the engine takes up.
The engine in the Celera is designed for aircraft use. It is a turbocharged turbodiesel.
In order to get the Chevrolet V-8 to work at altitude, you'd need to put a turbocharger on it which would destroy the fuel economy, especially in this application. Also, automotive engines are not designed to withstand the heavy duty cycle that this aircraft requires.
In order to get the Chevrolet V-8 to work at altitude, you'd need to put a turbocharger on it which would destroy the fuel economy, especially in this application. Also, automotive engines are not designed to withstand the heavy duty cycle that this aircraft requires.
Actually, the Chevrolet LS series small block V8 has been used in airplanes and helicopters. The only automotive engine series I am aware of that used in aviation. http://www.v8seabee.com/. https://en.m.wikipedia.org/wiki/Vertical_Hummingbird
There have been a number of experimentals running Mazda rotary engines, air-cooled VWs, Subaru boxers, and Corvair engines. I think there's a company that fairly recently started making some good-looking Suzuki engine conversions, as well. Probably a ton I'm missing, as well.
There are plenty of automotive engines that have been converted for use as aircraft engines. Subaru EA81 flat-4s, for one. I've also seen VW Beetle engines and Mazda rotaries converted for experimental aircraft use.
Snowmobiles and jetskis aren't automobiles, but many ultralight engines are based on snowmobile/jetski engine designs. (Rotax is very common, though I've seen at least one BD-5 with a Polaris snowmobile engine converted for aircraft use.)
Snowmobiles and jetskis aren't automobiles, but many ultralight engines are based on snowmobile/jetski engine designs. (Rotax is very common, though I've seen at least one BD-5 with a Polaris snowmobile engine converted for aircraft use.)
I expect in part fuel availability: Jet-A is available at practically all airfields nowadays, and the future of Avgas is still somewhat uncertain (the majority worldwide is still leaded!).
Nice and all, but I just got my private pilots wings a month and a half ago. I've looked at planes. I could buy an fleet of old pipers and burn 9gallons an hour throwing a plane away a year for what just one of these will probably cost. The tech is cool, but I would love to have something robust and cheep for the private pilots out there.
It won't make sense to buy for any individual. But if you run it close to 24/7 renting it out, fuel efficiency matters much more. You could have it on some kind of a scheduled service but sell out flights as a whole for businesses or families.
That way you still get a private jet experience but at a much lower price due to lower flexibility. Still appealing for most.
That way you still get a private jet experience but at a much lower price due to lower flexibility. Still appealing for most.
The idea of being stuck in a plane for hours with no windows is...odd.
This is the future of airplanes. Windows add cost and reduce the structural integrity of the plane.
Commercial airlines are already removing them.
https://www.bbc.com/news/business-44383220
Commercial airlines are already removing them.
https://www.bbc.com/news/business-44383220
Wow, this is a literal nightmare for flight anxiety sufferers.
Only if they don't replace them with even larger digital "windows." There's also been work towards electronic windows in aircraft.
Yeah but it'd be cooler if the sides were completely digital "windows".
What should these be called? Dindows? Digidows? Digdows?
I live in the arctic and I was thinking of building a home without windows but with same idea. It allows you to remove convective heat loss from windows almost entirely. Not to mention it's much cheaper than shipping up glass windows.
What should these be called? Dindows? Digidows? Digdows?
I live in the arctic and I was thinking of building a home without windows but with same idea. It allows you to remove convective heat loss from windows almost entirely. Not to mention it's much cheaper than shipping up glass windows.
I could see airlines charging more for "thrill" planes that have 360 immersion "windows" wrapped all around you.
Wonder Woman eat your heart out! (Her flying in that invisible jet in the cartoons always freaked me out when I was a kid)
Wonder Woman eat your heart out! (Her flying in that invisible jet in the cartoons always freaked me out when I was a kid)
Or special flights where the windows make it seem like you're flying into space and landing on Mars.
Not being sarcastic, my claustrophobia kicked in and my breathing literally became a bit heavier as I imagined sitting in a metal tube without windows. Had never considered how psychologically important windows are, before.
The last flight I was on had the window shutters down and lights off almost the entire flight.
[Off-topic] In the Mass Effect games series, Geth (a synthetic race) warships don't have windows as they are considered a structural weakness. In the game, there are some interesting conversations based on that.
Why not keep a thin horizontal sliver of glass instead of removing it completely. In most flights the blinds will be pulled down anyway. You can still peek outside, and no need for fancy electronics all around the fuselage.
Commercial airlines have a future? In the near future, only the wealthiest people will be able to fly, and good luck denying them windows. As for everyone else, Im thinking theyre taking the windows out because they are planning to convert over to cargo flights or something.
You can fly right now if you want to - flights are very cheap! What point are you trying to make?
You can buy a cheap ticket on an empty plane. Do the math. This is a passing thing, and airlines are either going to raise prices or go out of business.
You can buy a cheap ticket on an empty flight that then gets cancelled.
Why do you think that?
Because COVID has completely rejiggered the economy. Airlines legally are not allowed to pack hundreds of people into a cramped cabin. They're selling fewer tickets at lower prices, and they were already losing money on poor passengers to begin with.
Plus, the oil crash is still coming. Fracking has delayed it for a short time, and the covid lockdowns also have slowed consumption, but it is still inevitable. Before fracking, the U.S. army expected peak oil to happen sometime around 2015. Keep in mind, fracking is less efficient than old methods of oil extraction, and produces fewer barrels for the same amount of energy, and the energy for that extraction process comes from... oil. So we're burning the house down from both ends. Airlines don't stand a chance, in their current form.
Plus, the oil crash is still coming. Fracking has delayed it for a short time, and the covid lockdowns also have slowed consumption, but it is still inevitable. Before fracking, the U.S. army expected peak oil to happen sometime around 2015. Keep in mind, fracking is less efficient than old methods of oil extraction, and produces fewer barrels for the same amount of energy, and the energy for that extraction process comes from... oil. So we're burning the house down from both ends. Airlines don't stand a chance, in their current form.
Peak Oil? Banging that drum again? This must be at least the 7th major iteration of it.
For all that expense with fracking it still beats the snot out of solar and wind. Until we get over the hysteria around nuclear fossil fuels are going nowhere.
A real game changer could be a discovery in electrical energy storage. Even out the peaks from solar/wind. Solid chemical batteries aren't doing it - there's some cool stuff going on with liquid electrolyte batteries in Australia but I don't think the capacities or efficiencies of them can still beat out fossil fuels.
For all that expense with fracking it still beats the snot out of solar and wind. Until we get over the hysteria around nuclear fossil fuels are going nowhere.
A real game changer could be a discovery in electrical energy storage. Even out the peaks from solar/wind. Solid chemical batteries aren't doing it - there's some cool stuff going on with liquid electrolyte batteries in Australia but I don't think the capacities or efficiencies of them can still beat out fossil fuels.
Fossil fuels are going into the atmosphere, and they dont come back. I had no idea hn was so delusional about energy.
Which is why companies like this are going to be doing what Musk is doing with Electric vehicles.
Now, if they could make these for 2000-3000km flights and they ran on 250kWh to 350kWh electric they'd be what the future entails. Especially if they weren't piloted and were fully automated.
Now, if they could make these for 2000-3000km flights and they ran on 250kWh to 350kWh electric they'd be what the future entails. Especially if they weren't piloted and were fully automated.
Removing your energy source (fossil fuel) and replacing with energy storage doesn't fix anything - where does the energy to fill that storage come from? In some hypothetical future where renewable energy is very cheap, it will still be more efficient to use that energy to produce liquid fuel for planes.
Did you hear what I said about COVID? Also your imaginary battery that doesn't exist, is imaginary, and doesn't exist. Unless you want to fly around on a nuke.
And can we stop giving elon musk credit for everything? Tesla employs 48,000 people and contracts god only knows how many. It's pretty clear that elon musk is stealing credit for everyone's work, and Im sure the rest of the company physically cringes whenever people say stuff like "Elon is doing great stuff with batteries"
And can we stop giving elon musk credit for everything? Tesla employs 48,000 people and contracts god only knows how many. It's pretty clear that elon musk is stealing credit for everyone's work, and Im sure the rest of the company physically cringes whenever people say stuff like "Elon is doing great stuff with batteries"
Eh, kleenex, scotties, brand name recognition is a trite point.
And when it comes to EV batteries, Tesla is leading the field. 21700 batteries are a smart improvement over 18650 cells.
And I'll happily give the engineers at Tesla credit. However, realistically speaking they should be branching out and applying the same technology elsewhere. Especially in regard to hybrid vehicles.
It's not an either/or situation. We can eat our cake and drive it halfway too.
And when it comes to EV batteries, Tesla is leading the field. 21700 batteries are a smart improvement over 18650 cells.
And I'll happily give the engineers at Tesla credit. However, realistically speaking they should be branching out and applying the same technology elsewhere. Especially in regard to hybrid vehicles.
It's not an either/or situation. We can eat our cake and drive it halfway too.
There's a rendering further down showing windows. It may just be the prototype lacking them.
Probably because while private jet sounds great, the actual money will come from the military and cargo. A small plane at the efficiency of large cargo planes that can fly between most US airports would be a game changer for Fedex & UPS. They would save massive amounts with more direct routings, current small planes are just very limited and inefficient. Also, cargo planes could be unmanned much earlier than passenger flights.
I've seen similar concepts that cover the walls with hi-res lcd to simulate sky & landscape
It's frightening to think what the ultra low cost airlines would do with such video walls. I doubt it would involve showing the passing landscape but instead would be advertisements the entire flight.
On the face of it but then I think back to star trek and the giant screen they have on the bridge.
Speed seems to be almost comparable to a turbine aircraft in cruising speed if you go by their numbers, despite it being V12 piston prop driven. Cruising speed of the 500L is 450 mph and the cruising speed of a Gulfstream IV is 520 mph.
This air frame looks uncannily like the failed Planet Satellite in 1948 though.
This air frame looks uncannily like the failed Planet Satellite in 1948 though.
If anything the Planet Satellite plane looks more modern - its wings are nicely blended into the base of the fuselage. In contrast the Celera looks like someone got lazy on CAD an just intersected a bullet shape with a wing shape.
Big if true. The claimed performance on this is wild, especially since the pusher propeller configuration is usually less efficient than the puller configuration and its top speed is up there with the fastest piston engine aircraft (which are designed for speed not fuel efficiency).
Ok... lifting body, clean efficient wing, rear-mounted propeller to avoid disturbing the laminar flow - I get all of that. But what are the two gizmos mounted on the top of the fuselage between wing and tail? They look a bit big to just be the air intake for the engine?!
Presumably air intake and exhaust for the piston engine.
Is there a reason why small aircraft don't just use a car engine (with some appropriate gearing I guess)? Those have had so much R&D in them and they're pretty much as efficient as you can get - plus much easier to maintain and repair
Automotive engines are designed to produce power at a wide range of operating speeds, at the detriment of peak power output and peak efficiency. Aircraft engines can take advantage of the fact that they will be operating at a single RPM range for most of their life, which allows you to optimize every single aspect of the system for that speed. Aircraft engines also have much, much higher reliability, lifecycle, and quality control requirements than automotive engines.
For these reasons and a few others, you would basically end up redoing most of the engineering work on an automotive engine to repurpose it for aerospace applications, thus negating the savings of reusing the existing design.
For these reasons and a few others, you would basically end up redoing most of the engineering work on an automotive engine to repurpose it for aerospace applications, thus negating the savings of reusing the existing design.
Reliability would be my first concern. Power to weight is likely an issue as well. Here is some more info I found:
https://www.flyingmag.com/aircraft/do-car-engines-make-good-...
https://www.flyingmag.com/aircraft/do-car-engines-make-good-...
Although probably not the majority, many experimental aircraft do use car engines. I'm building a Zenith 750 kit aircraft and installing an engine from a company called Aeromomentum who convert Suzuki engines for use in light aircraft. The model I have installed is a 117HP engine originally designed for use as boat outboard motor. A sibling comment mentions that car engines aren't designed to operate continuously at high power. Outboards are. And there are benefits to using highly developed and tested engines vs traditional aircraft engines - efficiency being the most obvious.
Read the many reasons below, but one big one not named is that auto engines are not designed to be operated at near peak power constantly.
Auto engines are severely derated for use in airplanes, and then all of the advantage is gone.
Auto engines are severely derated for use in airplanes, and then all of the advantage is gone.
Some do, but not many
http://www.epi-eng.com/aircraft_engine_products/big-block_62...
http://www.epi-eng.com/aircraft_engine_products/big-block_62...
They do, though it requires some conversion to meet reliability requirements and to optimize for cruise. Over the years the Subaru boxer engines have been a popular starting point.
Efficiency at sea level does not equal efficiency at altitude. That said, there are some very impressive experimentals that do use auto engines.
Where are the windows? Human payloads need windows.
MPG*person is probably a better measure.
That aircraft is extremely risky, it is designed by amateurs who are not even using metric system. Pretty much guaranteed that FAA won't let it fly
by "that aircraft" do you mean the Celera 500L?
It looks like the view range is pretty limited based on the images, especially in the front. Can a pilot chime in and explain how important this is?
What's fun also is that "Celera" sounds just like "scélérat" in french, which is an old word for criminal.
This is super neat. Wish them the best of luck trying to get this commercialized!
One thing which was a bit surprising was actually how small the whole craft is. Scroll down the page and they show a human for scale. Looks like you can barely stand up in the center of it. But I’m sure as a private craft they will come up with some incredible interior designs nonetheless.
One thing which was a bit surprising was actually how small the whole craft is. Scroll down the page and they show a human for scale. Looks like you can barely stand up in the center of it. But I’m sure as a private craft they will come up with some incredible interior designs nonetheless.
Huge if true:
- 450 miles per hour, range of over 4,500 miles
- 18 to 25 miles per gallon (vs 2-3 mpg for jet)
- per-hour flight cost of just $328 (vs $2100 for light jet)
- 450 miles per hour, range of over 4,500 miles
- 18 to 25 miles per gallon (vs 2-3 mpg for jet)
- per-hour flight cost of just $328 (vs $2100 for light jet)
OK, at least they are not claiming 10x increases in fuel economy anymore, it reduced to the more reasonable 5x, which is sorta believable, especially since most of the affordable jets are not using latest generations of jet engines.
Let me guess: the catch is the high maintenance cost of the piston engine.
Let me guess: the catch is the high maintenance cost of the piston engine.
> A03 V12 piston engine
there's why it is cheaper! turbines are expensive, pistons are cheap.
there's why it is cheaper! turbines are expensive, pistons are cheap.
Sort of. Yes yes development costs.
They are claiming the plane is also cheaper to fly dramatically, and having a similar airspeed to modern jets. That's not easy.
Modern jetliners use "turbo-fans" which are just jets powering giant fans. This allows them to be -incredibly- efficient.
The complexity of the piston based engine is in the superchargers and how they get air into the engine at high speeds.
You can read about it from the highly famous WWII engine the Rolls-Royce Merlin _- https://en.wikipedia.org/wiki/Rolls-Royce_Merlin#Supercharge...
They are claiming the plane is also cheaper to fly dramatically, and having a similar airspeed to modern jets. That's not easy.
Modern jetliners use "turbo-fans" which are just jets powering giant fans. This allows them to be -incredibly- efficient.
The complexity of the piston based engine is in the superchargers and how they get air into the engine at high speeds.
You can read about it from the highly famous WWII engine the Rolls-Royce Merlin _- https://en.wikipedia.org/wiki/Rolls-Royce_Merlin#Supercharge...
[deleted]
Hmmm, a complex V-12 turbocharged piston single - sign me up, as long as I don't have to fly over water or mountains.
It's not real until it's in Microsoft Flight Simulator 2020.
As awesome as the new Flight Simulator is, as an avgeek the Flight model is very disappointing. X-Plane can, and has, been used to design real world aircraft because you input the aircraft geometry and it simulates how it should fly based on that. MSFS extrapolates a lookup table over the input geometry, making it useless for real-world aerodynamic predictions.
From the consumer perspective, both models are capable of outputting accurate results, but from the developer perspective, MSFS is no better than FS 98.
From the consumer perspective, both models are capable of outputting accurate results, but from the developer perspective, MSFS is no better than FS 98.
Which aircraft were actually designed with X-plane, and why? I've heard this several times but that never made sense to me.
I wouldn't be surprised if their blade element theory approach is superior to whatever Microsoft is doing (not familiar), but still both of those are optimized for realtime simulation, not for correctness.
When I wanted to analyze performance of a hypothetical rigid wing hang glider I went with XFLR5. That isn't a perfect tool by any means either but its algorithms should be miles ahead of X-Plane. Though of course you can't actually fly the plane in XFLR5, just do the math.
I wouldn't be surprised if their blade element theory approach is superior to whatever Microsoft is doing (not familiar), but still both of those are optimized for realtime simulation, not for correctness.
When I wanted to analyze performance of a hypothetical rigid wing hang glider I went with XFLR5. That isn't a perfect tool by any means either but its algorithms should be miles ahead of X-Plane. Though of course you can't actually fly the plane in XFLR5, just do the math.
I don't know about production aircraft, but NASA uses X-Plane pretty extensively for all kinds of research, including modeling flight dynamics for small UAVs. It's used often enough that several years ago I developed (and released on NASA's GitHub) a tool to simplify programmatic interaction with the X-Plane simulation engine. It's not nearly popular enough to make maintaining it a full time job (thankfully), but I do get pretty regular comments from NASA researchers and members of the public.
I have never heard of anyone using MS Flight Sim in the same way, although another fairly common use case for my library is to disable the X-Plane physics completely and just use if as a visualization tool. If someone developed a library that made that equally easy for MSFS, I can see it taking over that role. It certainly looks better the X-Plane IMO.
I have never heard of anyone using MS Flight Sim in the same way, although another fairly common use case for my library is to disable the X-Plane physics completely and just use if as a visualization tool. If someone developed a library that made that equally easy for MSFS, I can see it taking over that role. It certainly looks better the X-Plane IMO.
Beta eVTOL.
https://www.beta.team/
https://www.beta.team/
It follows then that helicopters are, for the time being, not real.
Looks like engine is 90% to blame for that economy
Uber for airplanes coming soon!
Amateur-built experimentals have achieved upwards of 50 mpg in realistic flying conditions, but they generally tended to be tandem-seat designs with minimal frontal area and low-powered engines.
More recently, the Pipistrel Taurus G4 (a highly modified sailplane with an electric motor between twin fuselages, designed to carry a pilot and three passengers) achieved just over 100 mpg at ~107 mph.
I eagerly await proof that the Celera--a significantly larger, heavier, and faster aircraft than Rutan's Catbird--actually achieves similar fuel economy. If true, it would be a pretty incredible leap for an industry that's been largely stagnant for decades, but these sorts of claims have a long history of being either sadly mistaken or outright fraudulent.