Hi guys.I just got a question from a friend that had seen a TV show where they flew around in a propeller plane that had a push-and-pull configuration. He asked me what the benefit is with that type of config. My answer (guess) was that it is a method of achieving greater reliability (twin engines) with minimal increase of drag (one body) compared to a "normal" twin engine plane that has three bodies (the crew compartment plus two engine compartments).The drawback would be inefficiency of the pushing propeller since the air that reaches it is disturbed by the pulling prop as well as the airplane body.Did I get it right or are there other benefits/drawbacks?

Yes you are right, there is less drag in a push-pull config :)The biggest benefit of having two engines in a push-pull arrangement is during an engine failure. In a normal twin with engines on the wings - when one fails the plane will yaw in the direction of the dead engine.So if the left engine fails the plane will try to turn to the left because the thrust of the functioning right engine is still pushing...so you have to stomp down some right rudder to counter that, in addition to trying to restart/feather the other failed engine.Pilots sometimes die in twins because they fail to mantain control of the plane (specially on takeoff which is the worst time for an engine failure in a light twin)But in a push-pull plane its so much easier because the thrust line is straight.....so when one engine fails its a big workload off the pilot compared to the work in a normal twin....no assymetric thrust to deal with! (Which is a *huge* load off your back)Just keep going straight and do the restart drills on the failed engine without worrying about contrallability :)

In the 70's when I was an active pilot I believe one could fly a push-pull without a multi-engine endorsement due to lack of yaw and recovery problems, including stall difficulties exclusive to non-inline ME aircraft.Anybody recall which amphibian used this?

Ronzie...that still stands today. You can get rated on a twin-engine push-pull plane with a clause on the license restricting u to centre-line thrust planes only.A push-pull amphibian?.....hmm interesting :) American plane?

Another drawback is that cooling can be a problem for the rear engine because of reduced airflow.Sometimes, taxiing is done without starting up the rear engine to prevent overheating. Unfortunately, that means that you must remember to start it before taking off. There are several reported accidents involving failure to have the rear engine powered up during take off.Also, things can get pretty loud in the cockpit with an engine close in front of you and another one close behind you.Wilson

How true!There is the old adage that a single engine pilot is better off loosing an engine in a single engine plane than he is in a twin.This is particularly true concerning the left engine unless the bird has counter rotating props.I took my twin check ride in an old Apache 160 (which I love). The Examiner kept shutting the right engine down which was a snap to deal with. Then finally he shut down the left. Asked me if I had everything done after I thought I had everything back under control. I checked flaps, gear, Throttles, Props, mixture, feathered prop. and like a dummy said yes. Then he reminded me that on the Apache your hydralic pump is on the left engine. You have to pump the gear up. Then it was clear why he had baited me with that right engine and I never forgot that.Another old saying: "Dead foot, Dead engine". (i.e. If you are having to stomp the right rudder to the floor, maybe with both feet while you are gettin a cramp in your leg, your left engine just quit on you)Throttles, Props (Pitch/RPM), and Mixture to the firewall. Then Mixture cutoff (hopefully on the dead engine), Throttle closed and feather the prop. All this while still flying the airplane. There is a pet word for this procedure. Anybody remember what it is?Years ago I remember reading about a situation where a turbocharger ran away on an engine giving an indication which made the pilot think that the other engine had failed. Results: He shut down the good engine and was in even more trouble.Happy flying:RTH

Well - as they say "the proof of the pudding is in the eating!". So in this case, there are many twins around in the world but very few push-pull. Must be a reason for that. Barry

Thats true...theres not many push-pullers out there. The only one that comes to my mind is the Cessna Skymaster:I cant think of a reason why they arent popular...perhaps they just *look* wrong to many people. They are more expensive to run. Perhaps its easier to change an engine on a conventional twin than a push-pull. The Skymaster is a maintenance beast with its engines very tightly fitted giving very little workroom.Too bad really...they look like neat planes!

Well some people like them. There are three Skymasters at my small local airport!David

I believe it was but I can't remember it. I could be way off.

The reason might be as simple as when I was considering getting one last year-my wife took one look at it and said "yuck! I don't like the way it looks..."I think they are great planes-the pressurized skymaster had my attention.However, I now fly a Baron and the wife is happy! I am happy too..:-)http://mywebpages.comcast.net/geofa/pages/rxp-pilot.jpg

Can't recall an amphib, but I'd bet it was probably a Piaggio.I remember having a plastic model of an Italian seaplane (not amphib), 1914 era, wire, stick and rag construction, which had flat bottom floats and push-pull V-something engines mounted in a pod on top.

>Thats true...theres not many push-pullers out there. The only>one that comes to my mind is the Cessna Skymaster:>>I cant think of a reason why they arent popular...perhaps they>just *look* wrong to many people. They are more expensive to>run. Perhaps its easier to change an engine on a conventional>twin than a push-pull. The Skymaster is a maintenance beast>with its engines very tightly fitted giving very little>workroom.>>Too bad really...they look like neat planes!>>Where did you get this model?Thanks Barry

Hello Barry,That's a real picture of a real plane!There is a Skymaster in the Avsim library though. Just search for on the description Cessna 337 SkyMaster... or here's the filename: C33704A.ZIPOr there is a slightly updated version of the very same plane at flightsim.com. It fixes a problem with switching Fuel tanks or something like that.The FS2004 plane was done by FS-Design Berlin.Cheers,Jim

The Skymaster... called "suck-and-blow" by one of my ground instructors! :-hahMartin767 fetishistIt's a lot like life and that's what's appealing