jcoloccia said:I'm pretty sure it took a lot of arm twisting to get Van to make twin SEAT airplane, nevermind twin engines. Honestly, I never thought I'd live to see a 4 seater come out of Vans so anything's possible, I guess.
Here's an interesting question. If you have 1 propellor driven by 2 engines via some sort of gearbox, is that a twin or a very funky single? I'm not suggesting anyone do this but I am curious how that's classified. I could make a good argument that the two engines coupled with gearbox is no more 2 engines than 6 pistons coupled with a crankshaft is 6 engines.
There must be a governing regulation somewhere but I couldn't find it.
jcoloccia said:Here's an interesting question. If you have 1 propellor driven by 2 engines via some sort of gearbox, is that a twin or a very funky single? I'm not suggesting anyone do this but I am curious how that's classified. I could make a good argument that the two engines coupled with gearbox is no more 2 engines than 6 pistons coupled with a crankshaft is 6 engines.
Captain Avgas said:Helicopters with twin turbines and one propellor (rotor) are classified as twins. When one engine stops the remaining functioning engine does not have to drive the dead engine.
jcoloccia said:Here's an interesting question. If you have 1 propellor driven by 2 engines via some sort of gearbox, is that a twin or a very funky single? I'm not suggesting anyone do this but I am curious how that's classified. I could make a good argument that the two engines coupled with gearbox is no more 2 engines than 6 pistons coupled with a crankshaft is 6 engines.
jcoloccia said:I'm pretty sure it took a lot of arm twisting to get Van to make twin SEAT airplane, nevermind twin engines. Honestly, I never thought I'd live to see a 4 seater come out of Vans so anything's possible, I guess.
Here's an interesting question. If you have 1 propellor driven by 2 engines via some sort of gearbox, is that a twin or a very funky single? I'm not suggesting anyone do this but I am curious how that's classified. I could make a good argument that the two engines coupled with gearbox is no more 2 engines than 6 pistons coupled with a crankshaft is 6 engines.
There must be a governing regulation somewhere but I couldn't find it.
n468ac said:It would be nice to see a 300kt airplane out of Van's ... maybe a modified 7 or 8
davidkarlsberg said:Zenith was working on a twin kit plane for a while. Not sure if they are still working on it but check it out, looks cool.
http://www.zenithair.com/gemini/
Best try, the -10 would need a freakin PT-6 to got 300kt's. But you'd need a composite wing to do it, or at least a Evo like wing. I'd like to build a -7 with a evo wing and a IO-540... . Not 300kt's, but hopefully cruise above 200kt's with any luck. Need to push the Vne a little during flight testing... doable? maybe.n468ac said:It would be nice to see a 300kt airplane out of Van's ... maybe a modified 7 or 8
fodrv7 said:The big advantage of the twin over the single is the difference in performance with one engine failed............ but then you have twice the chance of an engine failure.
Pete.
osxuser said:I'd like to build a -7 with a evo wing and a IO-540... .
smenkhare said:heh.
that's the reason i asked.
apparently they stopped working on it a year or two ago
matt said:Heard that without a feathering prop the engine out behaviour of the Gemini was less then ideal
jcoloccia said:That's true of many twins. Unless you properly bank into the good engine, close the cowl flaps, go to high RPM, feather the prop, precisely hold the proper airspeed and whatever else the POH says to do, many twins won't even maintain their altitude. In general, you're doing pretty good if you get a 100 or 200 fpm climb when you've done everything perfectly.
jrsites said:My MEL instructor told me that in most light twins, the second engine is only there to carry you to the crash site after the first one quits.
captainron said:Funny old joke, but maybe time for a more serious or experienced instructor. After having had real-life engine failures in twins,- when people ask if I've ever had an engine-out emergency, my answer is, "No, I've just had engine-out situations."
captainron said:Funny old joke, but maybe time for a more serious or experienced instructor. After having had real-life engine failures in twins,- when people ask if I've ever had an engine-out emergency, my answer is, "No, I've just had engine-out situations."
jrsites said:It was his way of illustrating that you have to take a piston twin seriously, and that in many ways the second engine made the airplane MORE dangerous, rather than safer. It was his way of pointing out that in many piston twins, if you lose an engine and don't do EVERYTHING right, and quickly, that second engine is actually going to do you more harm than good.
PainterJohn said:ya know what about a turbine powered 7? hmmmm i really hope the weather is better tomorrow LOL
osxuser said:I'd like to build a -7 with a evo wing and a IO-540... .
Not really. There have been a few retract RVs built over the years. There was an article in Kitplanes a couple of years ago about a retract -4 in Germany. Bottom line was 100+ lbs of stuff (100 lbs less usefull load) for a very few extra knots.Captain Sacto said:A retract rv-7 would be genuine speed burner (but I'm guessing might be too heavy and clumsy).
sprucemoose said:There have been a few retract RVs built over the years. There was an article in Kitplanes a couple of years ago about a retract -4 in Germany. Bottom line was 100+ lbs of stuff (100 lbs less usefull load) for a very few extra knots.
A properly faired fixed gear is not all that draggy, at RV speeds.
Captain Sacto said:I think there was a twin 2-place a/c marketed in the 70s called the Derringer. Didn't sell well if I recall..
I did one flight in a Wing Derringer at Mojave a few years ago. Its O-320s had been replaced by O-360s. I was expecting it to be quite the performer, but I was very disappointed. It probably had lower performance than an O-360 powered RV-6.Mike S said:I believe the complete name was "Wing Derringer". Pair of O-320. Only 5 built IIRC, and as the fates would have it, one is owned locally (Sacramento area) by a guy who also has a RV_3 in his collection.
jsherblon said:OK, how about modifying an RV with two engines on the wings and keep the fuselage engine! Three engines could give you way more load capacity. Of course you'd need extra fuel and a larger fuselage and wing, and it has to all metal, fixed gear to be a real RV....might look something like this