The potentially revolutionary Celera 500L aircraft
thedrive.com
thedrive.com
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.
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.
Which is why the jump in efficiency would be so extraordinary.
Props work better than jets at low elevation where the span of a propeller can work against a lot of high density air.
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...
That doesn't seem completely unreasonable.
A Pilatus PC-12 (which is the turoprop competition here) NXG gets around 4.3 mpg.
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.
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.
I have high hopes for the future efforts
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"
Something like Garmin Autonomí might eventually allow for single pilot flights while maintaining a reasonable level of safety.
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.
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
How would single-engine craft comply with ETOPS - the relevant standard for passenger flights, or equivalent?
So, without new regulation, this aircraft will not carry out "charter or scheduled flights in Europe" ?
And even if they somehow pull off that trick, that short skinny wing will make the MU-2 feel like a safe family minivan.
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.
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.
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.
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.
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.
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.
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.).
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.
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.
Why would you be shocked by flying at heights comparable to typical jet aircraft flying similar distances?
(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.)
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.
$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.
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.
[1]https://patentimages.storage.googleapis.com/3b/f3/9a/928c862...
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 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.
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.
Many other six seat planes are like that.
The base engine has been flying for several years. This is the turbocharged model. So it's an engine design with some flight experience.
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.
And I have a big suspicion that they use two of these engines inside.
Ref: https://en.wikipedia.org/wiki/Multi-Displacement_System
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.
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...
https://en.wikipedia.org/wiki/Multi-Displacement_System
https://en.wikipedia.org/wiki/Active_Fuel_Management
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...
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.
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.
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.
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
https://www.cia.gov/library/publications/the-world-factbook/...
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.
I believe engines make less power when the air in is hotter too as there is less delta T. Something something Carnot cycle
Anyway, I think the reduction of oxygen density is the primary driver for reduction in power as ambient temperatures rise.
For airplanes take-off, the lift is the issue I'd say.
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...
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.
> 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.
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.
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.
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.
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.
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.
I have a hard time believing they can get to such speed with just 500hp.
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.
You can have a naturally aspirated engine with electronic (even direct) injection, or a turbocharged engine with a carburetor, or any other combination.
I just wish carbureted was an easier word to spell after not using it for months at time.
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)
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.
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.
"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."
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.
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.
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.
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.
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.
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.
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.
At every level, the political power is structured poorly to make the subway (and regional infra in general) a low priority.
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.
Success is dependent on the gearbox.
This uses a single V12 Diesel engine. The Lear Fan used dual turboshaft engines.
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.
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...
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?
A mockup of a UAV version is shown in the article.
“It’s all about the laminar flow”[0]
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?
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.
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.)
That way you still get a private jet experience but at a much lower price due to lower flexibility. Still appealing for most.
Commercial airlines are already removing them.
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.
Wonder Woman eat your heart out! (Her flying in that invisible jet in the cartoons always freaked me out when I was a kid)
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.
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.
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 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.
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.
This air frame looks uncannily like the failed Planet Satellite in 1948 though.
https://www.flyingmag.com/aircraft/do-car-engines-make-good-...
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.
Auto engines are severely derated for use in airplanes, and then all of the advantage is gone.
http://www.epi-eng.com/aircraft_engine_products/big-block_62...
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.
- 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)
Let me guess: the catch is the high maintenance cost of the piston engine.
there's why it is cheaper! turbines are expensive, pistons are cheap.
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...
From the consumer perspective, both models are capable of outputting accurate results, but from the developer perspective, MSFS is no better than FS 98.
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 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.