- Jul 29, 2005
- Orange County, California
^ This post. You'll never see a "general" answer to the pusher-tractor question, because the final answer is completely airframe-specific.If the prop is unaffected by the air-frame then there is no differentiation between a tractor and a pusher propeller. So the discussion is really about the air-frame. Now is the prop in the wake of the air-frame more efficient than the fuselage in the wake of the prop? Again this is dependent mainly on the air-frame and there is not a one answer fits all. Both can be made to work.
While there are many exceptions in the real world and there are many practical design details that need to taken into account, a pusher prop can be slightly more efficient. Think aircraft like the Vmax probe, Taylor Mini-Imp and Piaggio Avanti. The first had other practicality issues.
Mid wing is also slightly more efficient but at times you do not want the spar right in the middle of the people or engine.
About the only thing you can say definitively on this question is that it's much harder to design an "equivalently clean" pusher aircraft than a tractor one. There will be more compromises in other areas (notably landing gear and engine cooling) for the pusher, which may or may not be "worth it" for the possible gain in cruise performance over the tractor design.
Is a pusher more likely to see a reduction in climb performance when "dirty" when compared to an "equivalent" tractor design? Yes. It's my opinion that if the climb performance of the aircraft is so marginal that this becomes a genuine safety factor in comparing pusher or tractor props in the design phase, then the project has much larger issues to deal with than which end to install the prop.