tomjnx wrote:
It’s somewhat unfair to compare the F100 figures of the Seneca with the F200 figures of the 337
Well, that has to do with the fact that the Seneca II is mostly flown at non-oxy altitudes whereas the 337P is pressurized and will fly at FL200 more often than say a Seneca II will fly at FL170 with all on board on oxy.
If you compare them at FL100, say for the non pressurized 337 which has similar performance in the low levels, then the 337 is significantly worse.
@ 75% power, best economy, 10,000 ft 186 kt/4.9 hr (26.3 gph/158 pph) =0.142 USG/NM / 900 NM range
@ 65% power, best economy, 10,000 ft 177 kt/5.6 hr (23.3 gph/140 pph) =0.132 USG/NM / 980 NM range
@ 75% power, best economy, 20,000 ft 205 kt/4.8 hr (26.5 gph/159 pph) =0.129 USG/NM / 950 NM range
@ 65% power, best economy, 20,000 ft 192 kt/5.6 hr (23.3 gph/140 pph) =0.121 USG/NM / 1050 NM range
In comparison to the Seneca II
@75% power at 10’000 ft 175 kt and 22 GPH = 0.125 USG/NM / 750 NM range
@65% power at 10’000 ft 165 kt and 20 GPH = 0.121 USG/NM / 850 NM range
Than at FL100, the 337 still has significantly more range and is 10-12 kts faster, the Seneca is more efficient however. I don’t have numbers here for FL170 (which as I recall is about the most efficient FL for the Seneca).
So in comparison with the the non pressurized variant of the 337, I would say that the Seneca is definitly more efficient but has less range.
What I would look at as attractive in the P337 is the pressurisation and the better range. What is a lot more unattractive is that it is an “exotic” airplane these days with few exemplars flying and that is appears to be very noisy. That alone disqualifies it more or less in Central Europe.
The only two countries (essentially) that “care” about noise levels of piston aircraft are Germany and Switzerland. The others don’t.
Which doesn’t mean oneself shouldn’t care about the amount of noise we produce.
I well remember a flight to Antwerp where I proudly presented my German noise certificate after landing for the purpose to reduce the landing fees, only for being told “you can make as much noise as you want”.
europaxs wrote:
only for being told “you can make as much noise as you want”.
quite rightly so.
Jan_Olieslagers wrote:
Why is nobody offering a similar design, powered by a couple of Rotaxes? Could make a damn good tourer, affordable to acquire and to operate. The known issues do not seem to be insurmountable.
There exist a somewhat similar design, well twin pusher at least, tandem seating. The Aeroprakt A36. With the propellers almost touching each other, it should be easy to handle as a twin. Good specs, MTOW 750 kg, max climb rate 2160 fpm (790 fpm single engine), 6h range
http://www.aeroprakt.kiev.ua/airplanes/about/id/11
The airplane has comfortable cockpit for long range flights (side sticks, elbow rests, seats adjustable in flight, efficient ventilation and optional autopilot system). A-36 has also a spacious luggage compartment designed for 100 kg (220 lb) of useful load, which can be used for various kinds of equipments and instruments.
The A36 may be a nice plane but it is not a push-pull. Besides, I am not sure it is really on offer, except as a one-off build, at corresponding price. But I am sure it WILL be noisy with twin pusher props.
You do find many push-pull aircraft among the seaplanes, where it is a quite logical method of integrating two engines. Think Do18 or the Seastar. Other than that there was the Rutan Defiant and the Adams 500 in a push-pull configuration.
In theend I don’t see too much advantage in that configuration. The advantages of a smaller rudder is eaten by the boom design, less efficiency of the pushing engine without the benefits of undisturbed airflow around the fuselage and propably more FOD.
The 337 does look kinda badass, though.
The Aeroprakt not so much. Tandem seating with that low payload doesn’t seem to fit many people’s idea of a nice 200hp tourer, too. Our 160 hp Capitaine will outrun that bird with more payload, similar fuel consumption and more range. Just needs more runway though.
I was going to buy a 337 until I got side railed by a Commander as my first aircraft.
They’re gray value for money. They do have the Cessna SID’s, so one has to comply with those in EASA-land. In FAA land that’s a non-event for part 91. The P337 is probably the cheapest pressurized twin you can get into. They’re ideally suited for Europe otherwise wight heir short takeoff capabilities and light weight. Grass is no problem. Well supported, and for those who like a long range aircraft, the aux tank upgrades you can add to the 337’s will make it an insane long range aircraft. Tip tanks, drop tanks and baggage tanks can get you well over 2000nm on these.
This one has the Skymaster configuration, but was perhaps less successful… Note Moto Guzzi engines, with special cylinders unique to the UAV. A guy I know bought a new old stock engine and put it in the motorcycle from which the engine was originally derived.
(The NG née IAI/TRW Hunter).
mh wrote:
The Aeroprakt not so much. Tandem seating with that low payload doesn’t seem to fit many people’s idea of a nice 200hp tourer, too. Our 160 hp Capitaine will outrun that bird with more payload, similar fuel consumption and more range. Just needs more runway though.
Yes, but not when it comes to total engine reliability for each flight. The basic idea is the same, to have a design with redundant engine configuration, but none of the less desirable side effects. Seems like this configuration is irrelevant for most private uses, except very special cases. But for those special cases it fits perfectly. With 3000 sold, the Skymaster was no flop, and it looks cool.
