The potentially revolutionary Celera 500L aircraft • Hacker News Board

Re: The potentially revolutionary Celera 500L aircraft

#211

Post by NovemberWhiskey » Thu, Aug 27, 2020, 3:03 PM UTC

kube-system wrote: post #150

davidgould wrote: post #60

Earlier quoted context omitted.

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…

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.

Re: The potentially revolutionary Celera 500L aircraft

#212

Post by mediaman » Thu, Aug 27, 2020, 3:17 PM UTC

sunstone wrote: post #148

brunooo wrote: post #101

Earlier quoted context omitted.

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…

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.

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.

Re: The potentially revolutionary Celera 500L aircraft

#213

Post by scott31 » Thu, Aug 27, 2020, 3:23 PM UTC

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

Re: The potentially revolutionary Celera 500L aircraft

#214

Post by NovemberWhiskey » Thu, Aug 27, 2020, 3:27 PM UTC

VBprogrammer wrote: post #203

SideburnsOfDoom wrote: post #187

Earlier quoted context omitted.

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/

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).

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).

Re: The potentially revolutionary Celera 500L aircraft

#215

Post by NovemberWhiskey » Thu, Aug 27, 2020, 3:42 PM UTC

baybal2 wrote: post #79

brunooo wrote: post #63

Earlier quoted context omitted.

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…

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.

Re: The potentially revolutionary Celera 500L aircraft

#216

Post by tonymet » Thu, Aug 27, 2020, 3:43 PM UTC

Mountain_Skies wrote: post #51

tonymet wrote: post #9

Earlier quoted context omitted.

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.

You nailed it

Re: The potentially revolutionary Celera 500L aircraft

#217

Post by walrus01 » Thu, Aug 27, 2020, 3:43 PM UTC

skykooler wrote: post #94

alfalfasprout wrote: post #61

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…

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.

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.

Re: The potentially revolutionary Celera 500L aircraft

#218

Post by hindsightbias » Thu, Aug 27, 2020, 4:03 PM UTC

baybal2 wrote: post #143

KMag wrote: post #121

Earlier quoted context omitted.

> Success is dependent on the gearbox. 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.

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...

Re: The potentially revolutionary Celera 500L aircraft

#219

Post by asdfadsfgfdda » Thu, Aug 27, 2020, 4:04 PM UTC

VBprogrammer wrote: post #173

qzw wrote: post #58

Earlier quoted context omitted.

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…

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.

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.

Re: The potentially revolutionary Celera 500L aircraft

#220

Post by aidenn0 » Thu, Aug 27, 2020, 4:05 PM UTC

qzw wrote: post #137

aidenn0 wrote: post #111

Earlier quoted context omitted.

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,…

$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.

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"