2 Seat, Kit built 150 mph @ 5 gph?

[thisadviceisworthles]

I have been reading about Europe's Ultralights and I am impressed with how fast and efficient they are.

There are multiple options that will carry 2 people/600lbs over 150mph on less than 5gph, typically with a Rotax 912. The Shark Aero (https://www.sharkaero.com/) can be built as an EAB kit, but I cannot find much information on the kit (or any that have been completed as EAB).

I would think that the Falco F8L could come close to this if it were equipped with a Rotax 912, but you can no longer buy the kit.

Are there any other US available kits that can meet or surpass these performance numbers?

[CarlOrton]

Sonex w aerovee at 8000’ is 150; w 120 hp jabiru 170. Fuel consumption w aerovee right at 5. Might be less with the jab.

[martymayes]

I don't think a 100hp Falco with an empty wt in the ~1100 lb range would have stellar performance. The original 135 hp version had a cruise speed of 120 mph. Until Alfred Scott came along, the Falco was a plans built airplane. I believe Tony Bingelis built his from scratch. So if one was a glutton for punishment, I'm pretty sure a set of plans could be found.......

[BoKu]

...Until Alfred Scott came along, the Falco was a plans built airplane...

Until Scott came along, the Falco was a factory-built airplane. Frati originally dismissed the idea that it could be built in basements and garages, believing the design too complicated for amateur construction. Frati's secretary helped Scott talk him into it.

But, yeah, a 100 hp Falco would not be a worthwhile airplane.

[martymayes]

But, yeah, a 100 hp Falco would not be a worthwhile airplane.

How much weight could be shaved off if it were "compositized?"

[WLIU]

There is one carbon fiber "Falco", that came out of Oz, the Furio. I think it is a 180hp airplane.

All used core engines cost about the same at the aircraft salvage yard. Why mess with 100hp when you can get 160 or 180 for the same price? And you don't pay less to overhaul 100hp either.

Best of luck,

Wes

[BoKu]

How much weight could be shaved off if it were "compositized?"

Based on my experience with carbon fiber, probably between 15% and 30%.

If you want efficiency, the easiest way to get it is to reduce frontal and wetted area to the bare minimum. Given the parameters, I think I'd hunt up a Pulsar XP.

--Bob K.

[Bob Dingley]

[QUOTE=thisadviceisworthles;

There are multiple options that will carry 2 people/600lbs over 150mph on less than 5gph, typically with a Rotax 912. [/QUOTE]

Pipistrel VIRUS Short Wing fits fits to a tee. Two seat, 912, 147 KTS, 600 useful. (Motorglider version. Prop on the ELSA version holds it back to 120 KTS.)

[mmarien]

You can get 5gph out of an O320 with electronic fuel injection and ignition. When I'm chasing C182's I get 5gph at about 145 mph in my Glasair II. If I'm cruising WOT (Savvy style) and 2400 RPM I get 165 mph at 6.5gph. I haven't tried 2700 RPM. My Glasair II has 500 useful load with full fuel. The new iS 915 Rotax in a lighter composite will probably put you near 200 mph under 5gph in a lighter composite.

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[max_reason]

To the best of my knowledge, the best example is the pipistrel virus sw with rotax 912iS engine. The following are some specifications:
- 2 seat ... side-by-side
- cruise speed at 75% power == 275kph == 171mph == 148kt
- fuel economy at 75% power == ~3.3 gallons per hour == 12.5 liters per hour == 83kpg == 52mpg
- fuel capacity (standard fuel tanks) == 100 liters == 26 gallons
- fuel capacity (extreme fuel tanks) == 300 liters == 79 gallons
- endurance at 75% power (standard fuel tanks) == 07.88 hours
- endurance at 75% power (extreme fuel tanks) == 23.64 hours
- range with standard fuel tanks == 2165km == 1346 miles
- range with extreme fuel tanks == 6500km == 4040 miles
- longest hop across north pacific ocean == 3850km == 2392 miles (California to Hawaii)
- longest hop across south pacific ocean == 3000km == 1864 miles (Isla Robinson Crusoe to Easter Island)
- safety margin when flying longest hop across pacific ocean (standard fuel tanks) == -1685km == -1046 miles (airplane ditches into ocean 1046 miles from Hawaii)
- safety margin when flying longest hop across pacific ocean (extreme fuel tanks) == 2650km == 1648 miles (huge safety margin)
- approximate airplane weight with standard fuel tanks == 275kg == 605 lbs
- approximate airplane weight with extreme fuel tanks == 300kg == 662 lbs
- MTOW (maximum rated takeoff weight) with standard fuel tanks == 600kg == 1323 lbs
- MTOW (maximum rated takeoff weight) with extreme fuel tanks == 750kg == 1654 lbs
- weight of 100 liters of gasoline (to fill standard fuel tanks) == 070kg == 155 lbs
- weight of 300 liters of gasoline (to fill extreme fuel tanks) == 210kg == 465 lbs
- maximum rated payload including fuel, cargo, pilot, passenger with standard fuel tanks == 325kg == 717 lbs
- maximum rated payload including fuel, cargo, pilot, passenger with extreme fuel tanks == 450kg == 992 lbs
- maximum rated payload including cargo, pilot, passenger with standard fuel tanks FULL OF FUEL == 255kg == 560 lbs (200 lbs pilot, 200 lbs passenger, 160 lbs cargo)
- maximum rated payload including cargo, pilot, passenger with extreme fuel tanks FULL OF FUEL == 240kg == 530 pounds (200 lbs pilot, 200 lbs passenger, 145 lbs cargo)

A few notes:
- The 100HP Rotax 912iS engine (computer controlled fuel injection) is roughly 25% more fuel efficient than the regular 100HP Rotax 912 engines. That's significant!
- The Rotax 912 engines run best on premium automobile fuel (up to 10% ethanol). This is much cheaper than 100LL, which further reduces operating costs.
- Available with MTV-33 constant speed propeller to achieve better climb performance and better fuel economy.
- Can be registered as LSA, glider or experimental (most registered as gliders == no medical required).
- Available as kits or fully assembled airplanes.
- About 95% carbon fiber (except engine).
- Available with air-brakes - get them !!!
- Available as tail-wheel or front-wheel.
- Available with nearly any avionics.
- Takeoff in 80 meters at MTOW.
- Landing can be much shorter.

Due to FAA rules, an LSA version:
- is artificially speed limited to 120kts.
- cannot have a constant speed propeller.
- cannot have 300 liter extreme fuel tanks (MTOW is too high).
- actually, could have 300 liter tanks but have MTOW specified as 600kg in the specs (funky).

These airplanes are so sleek, low drag and aerodynamically efficient... they don't want to slow-down or land (glide ratio == 17:1). This is why it is insane to not select the air-brake option. Also, the tail-wheel version is slightly lower drag and thus slightly more efficient (glide ratio == 17:1 versus 15:1).

The numbers shown above assume constant speed propeller and tail-wheel model (the most fuel-efficient combination). With regular propeller and nose-wheel the maximum range with 300-liter tanks is likely about 5800km instead of 6500km... but this is just an estimate (11% less efficient).

Owners indicate that "best economy speed" is roughly 240kph to 250kph, and this can boost fuel economy 10% to 20%. Different owners report different results.

I don't understand why, but the "service ceiling" for the airplane is specified as 23,500 feet. That's amazing, and well above where almost anyone would want to fly. Nonetheless, another way to get better fuel economy is to fly at a high altitude to reduce drag even further. Certainly up to 18,000 feet is viable with a Mountain High oxygen system. The ability to fly at high elevations is also a way to greatly increase the probability of finding an altitude with zero or little turbulence in those cases where low turbulence at lower altitudes is difficult or impossible to find.

Note that many owners say they are happy to fly and the slightly lower "economy speed" on short flights, but when flying extremely long range flights, everyone seems to value reducing the length of time they are in the air much more than reducing fuel consumption. The only exception to that is obvious... when going just a bit further avoids an intermediate fuel stop entirely (thereby saving time, effort and expense), or when flying over thousands of miles of ocean in cases where the safety margin is getting low. As one example of why "getting there sooner is more valuable than saving some money), to fly from California to Hawaii takes 14 hours at the nominal 75% power cruise speed of 275kph. To fly at 250kph would add about 1.5 hours more (15.5 hours). Another consideration is, a 14 hour flight can be completed entirely in the period from dawn to dusk, but 15.5 hours cannot (at least not when flying from west to east (against the sun)). Of course night flights are generally less turbulent, and during full moon one can see almost as well as daytime.

I am not aware of any other airplane that is good at bush/STOL/mountain/backcountry (especially if you buy the stardard tailwheel configuration plus the additional option of an extra set of Beringer Tundra XL wheels/brakes with 26" tires) ... AND ... also capable of long-range non-stop flights ... AND ... extremely fuel efficient and thus low cost of operation. That's why I recently purchased one with tail-wheel, 912iS engine, air-brakes, 300-liter extreme fuel tanks, MTV-33 constant speed propeller, the extra set of wheels/brakes/tires for bush/STOL/mountain/backcountry. I expect that 95% of pilots only have one of these interests, and would therefore buy regular fuel tanks, regular propeller, and only the standard small wheels (which are still pretty good for all but the most extreme bush/backcountry landing spots)... and spend about $30K less. Expect the price range to be $150K to $195K with rotax 912iS engine, and somewhat less expensive with the cheaper rotax 80HP and 100HP 912 engines that have carburetors instead of fuel injection. Note that one of these with 912iS engine and not very many hours just went up for sale recently. Anyone interested should let me know and I'll hook you up with the owner. There are also a couple Sinus for sale, which are very similar but have longer wings and much longer glide ratios. They are "motor-gliders" (which this SW is too, technically, or at least can be if you wish). The Sinus has a lower top speed but is an excellent glider and also very efficient (probably a 120kt airplane/glider at cruise). These SW have just under 11 meter wingspan while the Sinus is about 15 or 16 meters as I recall (but don't count on that).

Here are three photos of the three examples of the airplane (two nose-wheel and one tail-wheel). Apparently only the first has the 912iS engine, but not sure. The last one has Beringer wheels/brakes and large tires (not sure how large though).

This airplane won the NASA fuel-efficiency awards the two (?or three?) years NASA ran the competition. So... it must be rather fuel efficient. And that was before they put the rotax 912iS engine on the airplane and increase fuel-efficiency another 25% or so.