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The potentially revolutionary Celera 500L aircraft

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Re: The potentially revolutionary Celera 500L aircraft

#81

Post by karlkatzke »

baybal2 wrote: post #49
Stevvo wrote: post #30

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 m…

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.

One engine, a turbocharged V-12.

Re: The potentially revolutionary Celera 500L aircraft

#82

Post by jeffreyrogers »

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).

Re: The potentially revolutionary Celera 500L aircraft

#83

Post by aeternum »

Gravityloss wrote: post #74
scarier wrote: post #45

For some perspective, the Scaled Composites Catbird (powered by a 210-hp V6) achieved just over 20 mpg at 200 mph with close to 1000 lbs of payload (it could carry a pilot and four passengers) in the late '80s and early '90s. 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.…

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 mini…

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.

Re: The potentially revolutionary Celera 500L aircraft

#84

Post by ledauphin »

davidgould wrote: post #60
baybal2 wrote: post #43

Earlier quoted context omitted.

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.

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.

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.

Re: The potentially revolutionary Celera 500L aircraft

#85

Post by akrain »

davidgould wrote: post #60
baybal2 wrote: post #43

Earlier quoted context omitted.

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.

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.

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

Re: The potentially revolutionary Celera 500L aircraft

#86

Post by scarier »

Gravityloss wrote: post #74
scarier wrote: post #45

For some perspective, the Scaled Composites Catbird (powered by a 210-hp V6) achieved just over 20 mpg at 200 mph with close to 1000 lbs of payload (it could carry a pilot and four passengers) in the late '80s and early '90s. 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.…

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 mini…

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.

Re: The potentially revolutionary Celera 500L aircraft

#87

Post by Meandering »

Gravityloss wrote: post #74
scarier wrote: post #45

For some perspective, the Scaled Composites Catbird (powered by a 210-hp V6) achieved just over 20 mpg at 200 mph with close to 1000 lbs of payload (it could carry a pilot and four passengers) in the late '80s and early '90s. 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.…

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 mini…

The design of the body reduces drag and acts as a mechanism for lift.

https://en.wikipedia.org/wiki/Lifting_body

Re: The potentially revolutionary Celera 500L aircraft

#88

Post by Stevvo »

Mountain_Skies wrote: post #52

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.

Re: The potentially revolutionary Celera 500L aircraft

#89

Post by Retric »

qzw wrote: post #58
scarier wrote: post #45

For some perspective, the Scaled Composites Catbird (powered by a 210-hp V6) achieved just over 20 mpg at 200 mph with close to 1000 lbs of payload (it could carry a pilot and four passengers) in the late '80s and early '90s. 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.…

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 t…

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.

Re: The potentially revolutionary Celera 500L aircraft

#90

Post by Robotbeat »

scarier wrote: post #86
Gravityloss wrote: post #74

Earlier quoted context omitted.

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 mini…

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 clim…

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?

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