Long-Awaited Celera 500L 'Bullet' Plane Is Finally Revealed (cnn.com) 65
The Grim Reefer shares a report from CNN: The whispers started three years ago. A mysterious bullet-shaped plane was spotted at the Southern California Logistics Airport near Victorville in April 2017. Its unusual design prompted immediate speculation, with military website The War Zone being the first to report that the aircraft was the work of California-based Otto Aviation -- and that development was very much under wraps.
Now, in the late summer of the strangest year in aviation history, the Celera 500L has finally been revealed to the world, with the launch of a new website and a bunch of very cool new photos. What we're looking at is a six-person private craft that promises to fly at jet speeds, but with eight times lower fuel consumption, and a range that's twice that of a comparably sized craft. Bold claims indeed. Otto Aviation says on its website that 31 successful test flights have so far been performed, with aerodynamic efficiency proven in 2019, bolstering its declaration that "the Celera 500L is the most fuel-efficient, commercially viable aircraft in existence."
Now, in the late summer of the strangest year in aviation history, the Celera 500L has finally been revealed to the world, with the launch of a new website and a bunch of very cool new photos. What we're looking at is a six-person private craft that promises to fly at jet speeds, but with eight times lower fuel consumption, and a range that's twice that of a comparably sized craft. Bold claims indeed. Otto Aviation says on its website that 31 successful test flights have so far been performed, with aerodynamic efficiency proven in 2019, bolstering its declaration that "the Celera 500L is the most fuel-efficient, commercially viable aircraft in existence."
North American Aviation P-51 Mustang (Score:1)
North American Aviation P-51 Mustang photos (Score:2)
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Yep it sure did. But the best economy one could expect was close to 6 miles per gallon, assuming you didn't want to really fly it at even 1/2 it's ability. There's no way one could run it at the max airspeed of 435 and get even close to that.
So yea.. there's a difference here.
Re: North American Aviation P-51 Mustang (Score:1)
Incidentally, the Mustang could also fly at "jet speeds" apparently, as defined by TFS.
I've never heard anyone use that particular phrase before, but it's a wonderful one. Right up there with "assault-style weapons". No clue what either of them mean, but they're fantastically versatile.
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There was a time, not too long ago that a P-51 was the best toy for a big boy. After you got bored with a 930, a 308 and a Countach, you bought a P-51.
I knew of a winner of the ''he who dies with the most toys wins'' unfortunately he flew his ultimate toy [P-51] into the side of a mountain. But what a way to win the game.
Re: North American Aviation P-51 Mustang (Score:1)
I knew of a winner of the ''he who dies with the most toys wins'' unfortunately he flew his ultimate toy [P-51] into the side of a mountain. But what a way to win the game.
Legend. If I had to pick a way to go out ... definitely in my top 3.
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At that point the laminar flow was mostly theoretical. It is debated how much laminar flow there was given the surface finish.
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Not really relevant. This is about maximizing laminar flow across the fuselage. Not wings.
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The body has no lift? (Score:2)
Why is the body of the plane designed to have no lift? The top and bottom of the body is the same shape, rather than being flat on the bottom.
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Why is the body of the plane designed to have no lift? The top and bottom of the body is the same shape, rather than being flat on the bottom.
My guess is that's it's more efficient to use the body to feed clean air to the propeller than to create lift.
You know something we don't? (Score:2)
Why is the body of the plane designed to have no lift? The top and bottom of the body is the same shape, rather than being flat on the bottom.
How do you know the fuselage doesn't provide any lift?
To me, it looks like the cross section of a supercritical airfoil: https://en.wikipedia.org/wiki/... [wikipedia.org].
It does provide lift. Evidence: the wing position (Score:5, Insightful)
Perhaps you said that because the fuselage isn't flat on the bottom and curved in top. The reason it's not flat on the bottom is because the that would have higher drag (and fuel consumption) than the shape it has. It can still produce lift, though.
Very roughly half the lift of a typical aircraft is due to the *shape* of the wing and half I due to the angle of attack, the wing facing about 2.5 degrees "up". That is, since the plane is pointed slightly up, and the wing wants to move through the air edge-on, it tends to go slightly up.
The fuselage also has lift from angle of attack. That's true even if it's completely symmetrical top and bottom. In fact, one popular model airplane design has a box fuselage and flat slab wings. They fly fine (though airfoil wings would be even better).
Note in the pictures how far back the wings are. The wings are only carrying the back half of the plane. What's holding up the front of the plane?
The center of lift is about 28% from the leading edge / nose. Which means for the fuse, we can treat it as if the lift were 28% from the front of the aircraft. Therefore, fuselage lift tends to lift the front of the plane. That may be what's holding thr front of the plane up when in cruise. :)
Of course, the pics don't tell us the weight distribution. It may also be that almost all of the weight of the plane is in the rear and the wings are at the CG.
* Typical values given. Values vary greatly (Score:3)
I said:
Very roughly half the lift of a typical aircraft is due to the *shape* of the wing and half is due to the angle of attack, the wing facing about 2.5 degrees "up".
I should have clarified - the proportion of lift due to the airfoil va the AoA varies greatly between different aircraft and different phases of flight. As I mentioned, some model aircraft get 100% of the lift from AoA. Some WW2 fighters do as well. Some airliners cruise at 0 AoA, getting all of their lift from the airfoil during that ph
It would be good to know more about the design. (Score:2)
Everyone: AoA is Angle of Attack [wikipedia.org], the angle at which the airplane meets the air.
A long time ago I worked on a flight line. But I was completely unaware that an aircraft could be designed that way.
It would be good to know more about the design of the Celera, and why that design was chosen.
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The classic explanation of how a wing produces lift due to its asymmetric shape is totally wrong, as far as I know. Angle of attack is the main factor. I experimented with model gliders as a child, and they all had uniform profile wings. I had a system to change the angle of attack by changing the center of gravity. At one extreme, I could get a lot of lift at low airspeed, just below stall. At another extreme, I could hurl a glider at maximum speed, and it would fly.
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You can indeed make toys with symmetrical wings.
People can and do make airliners that cruise at 0 AoA, meaning the 140,000 pounds of aircraft is held aloft by the asymmetric curve of the wings.
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If you look at a wing in a wind tunnel you'll see that, at positive angles of attack, the airflow creates the shape of a classic wing, even if the actual wing has a symmetric cross-section. Example (although it's not a symmetric cross-section): https://www.youtube.com/watch?... [youtube.com]
I suspect that if someone analyzed them in sufficient detail, they would find that the various explanations of how a wing generates lift are equivalent descriptions, depending on whether you're in the frame of reference of the wing or
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There must be a lot of weight at the back. The air intakes and the propeller are there, so the motor is probably in between.
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The article explicitly mentions a v12 sat at the back.
Suspect the fuel's in the wings but engine and gearbox at the rear offsets the pilots up front.
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Why is the body of the plane designed to have no lift? The top and bottom of the body is the same shape, rather than being flat on the bottom.
You don't need an airfoil shape to produce lift. Clearly the intent is to reduce drag as much as possible.
What I would like to know is what the wing loading is. The weight might be deceptive because of the "fatness" of the design but those skinny little wings suggest a very high wing loading. That would translate to a very fast takeoff and landing speed unless the flaps (not evident from the pictures) were very effective.
"... most fuel-efficient, commercially viable..." (Score:2)
In the first photo [cnn.com], the wings look much smaller than in one of the other photos.
"... the Celera 500L is the most fuel-efficient, commercially viable aircraft in existence."
I would very much like to understand more about the Physics. If the Celera is so efficient, why weren't other aircraft designed that way?
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If the Celera is so efficient, why weren't other aircraft designed that way?
Because there are other things to consider too and people like to invest in what they know works. There actually are planes built around similar design goals - check out the Piaggio P.180 Avanti. Though the Celera brings things to an extreme. Just look at the cockpit windows.
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Because generating lift on a fuselage is throwing energy away. A fuselage -- any fuselage -- has a very low aspect ratio, and its induced drag (that's the drag penalty occurred specifically because you're generating lift) is inversely proportional to the aspect ratio. Lift belongs on the wing.
Incidentally, this effect is where the expression "going ballistic" comes from. If you pitch an airplane nose-down enough to make the lift go to zero -- which puts you in a ballistic trajectory -- the induced drag goes
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It depends on your speed. If you're flying slowly the induced drag dominates and you want to have as high aspect ratio wings as you can to minimize that. As you get going faster induced drag drops and parasitic drag increases, with lower aspect ratios becoming optimal.
Two red flags (Score:2)
1. Laminar flow is not magic or new. Things like bugs, rain, turbulence, and high angles of attack can convert laminar into turbulent flow.
2. A V-12 diesel engine probably does not have the best power-to-weight ratio. If it did, other piston planes would be using them. A turbine engine might be better. If the plane is flying at higher speeds, it will have to fly at higher altitudes, and a turbine engine is more efficient a
Re:Two red flags (Score:5, Informative)
Frontal Area (Score:2)
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P180 Avanti explained (Score:3)
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It is a pusher, not a puller. (Score:4, Interesting)
A puller (tractor) airplane is much quieter because propellers work in the clean undisturbed air.
This plane will be noisy in the air. What is not good for flying above or near the cities. Complaints about the aviation noise are becoming omnipresent. People do not want to hear it anymore.
Re:It is a pusher, not a puller. (Score:5, Insightful)
One of its main design constraints is maintaining laminar flow. Laminar flow across the body means that it won't be more noisy than a puller.
A design as efficient as this almost can't be noisy by definition.
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I would like to hear it flying. The pictures alone are not enough to convince me. I saw many pushers (because I fly FPV RC planes), and they were always noisy. Always, no matter what.
I prefer twin engine (on wings) puller configuration.
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Same thing as with Piaggio P180. It is quite noisy, though in cruise it doesn't really matter and the cabin noise is allegedly reasonable.
LOL (Score:1)
As if people who fly private give a hoot about fuel consumption.
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As if people who fly private give a hoot about fuel consumption.
Exactly. People who fly private care far more about looking good than fuel efficiency, which is another reason I think sales will struggle, because it's basically fugly.
Remember when Tom Hanks thought he had bragging rights owning a PT Cruiser? Yeah, that kind of appeal.
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If you lower the cost to the level of commercial travel, you've picked up millions of potential passengers.
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You have zero knowledge about the aviation market. There are plenty of places where people commute by flying, such as Vancouver. In these places an air taxi service using this airplane would make lots of money. Basically there's already a huge market for this in air taxis .. google air taxi and educate yourself.
WGAF? (Score:2)
they're just shiny new ego-wanking status toys for the eminently guillotine-worthy.
Eight times lower fuel consumption? (Score:1)
The article says "eight times lower fuel consumption". That just sounds totally implausible. Powered air transport is already highly optimised. As far as I know, the fuel usage per passenger mile of an airliner is about the same as for a car. The fuel usage for an aircraft looks big, because of the greater distances traveled. Perhaps this new vehicle coasts on thermals, like some birds do, but I saw no suggestion of that.
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The article says "18 to 25 miles-per-gallon fuel economy". That does appear to be on the same scale as a typical family car, so if this thing is carrying 6 passengers + 2 crew when fully occupied, that would indeed be around 8x as efficient as the airliner you describe, in passenger-mile terms.
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If fuel efficiency were truly improved 8x, then that would go a long way toward making battery-powered flight more likely.
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Possibly dumb question, but isn't the problem here less one of fuel efficiency and more one of energy density? Regardless of overall fuel economy I thought the problem was that the weight of the batteries needed to support powered flight was simply so much more than the equivalent weight of avgas due to the lower energy density of rechargable battery cells.
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A typical airliner already has the same miles-per-gallon economy as a car, per passenger mile, when the plane is reasonably well occupied and flying in normal conditions. The eight times efficiency improvement just looks like bad engineering analysis.
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Fuel accounts for the vast majority of the cost of business aviation -- something like 70% if memory serves. An 8x reduction would be huge.
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Good old "times less" again. WTF... do they really mean 1/8th?
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GA aircraft are generally quite inefficient, much less efficient per passenger-mile than commercial airliners. This thing promises to bring airliner efficiency to General Aviation, which would be quite an achievement. I think they will be successful, their physics and engineering is proven, it just wasn't ever used all at once in one design, not even in the Piaggio P180 because it used turboprops rather than diesel engines.
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That comparison is best-case to worst-case. A diesel engine does get far better fuel economy than gasoline (at the cost of additional weight), but even then the 8X improvement claim is in comparison to small planes with jet engines, which are among the least fuel-efficient ways to fly.
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I was basing my gallons-per-passenger-mile on an article I read some time ago, regarding incremental improvements in passenger aircraft aerodynamics. I would admit that a small jet aircraft would be far less efficient than a fully laden airliner. How much of a fuel consumption problem are small private jet aircraft? I am guessing pretty much negligible, compared to airliners.
I need to look up the efficiency advantage of diesel versus petrol engines. I do not think it is very big. There is a theoreti