wolit@rabbit.UUCP (Jan Wolitzky) (09/12/84)
[No, this is not about a group of farmers opposed to drug dealers...] > Pusher propellers are more efficient than tractor propellors because > they do not spoil the airflow over the wings. Interesting -- I always thought TRACTORS were more efficient because of the INCREASED airflow over the wing behind the prop. (Another effect of which is increased control surface effectiveness: every pilot report I read on a T-tail plane comments on the higher elevator forces required for rotation, for example. Compare the straight-tail and T-tail Piper Lances, for instance.) [By the way, Bob, it's cheating to spell "props" both ways just to get one right. Note how I cleverly avoid the error...] As to the "good aerodynamic reasons" for the droop wingtips on the B-70, the swing wings on the B-1, the forward-swept X-29, etc.: Sure, you can come up with post hoc justifications for these. I'm sure that Cessna could list good reasons for building high-wingers and Piper could list good reasons for building low-wingers. Hide-away headlights on Corvettes and old T-birds probably reduced drag, too, and I wouldn't be surprised if some Detroit engineer claimed that all the late-50's fins actually improved lateral stability. That doesn't mean that the reason for considering them in the first place wasn't a search for a good sales gimmick. Jan Wolitzky, AT&T Bell Labs, Murray Hill, NJ