Ba97 From Canada, joined Apr 2004, 377 posts, RR: 0 Posted (11 years 1 month 1 week 2 days 4 hours ago) and read 2697 times:
Please excuse my naivete on this:
Is there any engineering design reason why props are on the front of the plane or engine on commercial aircraft, thus "pulling" compared to backwards facing and "pushing". I have seen pictures of some military planes (German I think) and small private planes with a prop on the rear of the plane. With the overwhelming majority on the front, I expect there is a definite reason but then why the oddities?
there is economy class, business class, first class...then Concorde..pure class
Starlionblue From Greenland, joined Feb 2004, 17365 posts, RR: 66
Reply 1, posted (11 years 1 month 1 week 2 days 4 hours ago) and read 2658 times:
While I am not 100% sure, I would say the main problem is weight distribution. Before long propshafts were feasible, putting the prop in the ass of the plane was not possible because the weight distribution would be off with an engine mounting behind the wing. With wing mounted props (as with wing mounted jets), you want the weight to be on the front of the wing to decrease the tendency of the wing to twist up.
As far as I have been able to discern from previous discussions of pushers on this forum, they are theoretically as efficient as pullers.
Problem #2: Air AFTER the plane is more turbulent. Pullers get less turbulent air and so can be more efficient. I'm not entirely sure about this one.
Problem #3: At least in smaller fighters, the pilots don't enjoy bailing out only to be chopped to pieces by their own prop.
The German plane you are referring to is probably the Do-335 Pfeil. Yes, it had a pusher prop and rear engine, but it ALSO had a nose prop and front engine. Very cool plane http://www.aeroflight.co.uk/profile/d335top.htm. The Pfeil resolved the bailout problem by having a jettisonable prop and fin.
"There are no stupid questions, but there are a lot of inquisitive idiots."