Tuesday, August 25, 2009

Tractor vs. pusher

There is lots of strong feelings about tractor vs. pusher propeller configuration but no exact generic answer. Here is one article about the topic. Does not make definitive answer, but gives some background for the topic:

http://www.flyingmag.com/technicalities/1582/pusher-pusher.html

Here is another article:

http://dic.academic.ru/dic.nsf/enwiki/514042

Forum discussion

Another forum discussion

http://www.aiaa.org/content.cfm?pageid=406&gTable=mtgpaper&gID=50663

Tractor (prop forward of laminar flow wing):

http://www.aiaa.org/content.cfm?pageid=406&gTable=Paper&gID=1248

2 comments:

Thad Beier said...

Interesting set of articles, Karoliina. In the end, while I am a Rutan fan, even he has seen the advantages of tractor engines in his later career.

One thing that none of the articles mentioned was the desirability of seeing the prop, and to some extent, the engine. I would really like to see the prop when I call "Clear!" to make sure there's nobody about to be chopped up. If there is fire in the engine compartment, that's really nasty business in a tractor single engine plane, but at least you know about it right away.

Look at Cirrus -- they had nothing but trouble with their VK-20, and have set the world on fire with their tractor birds.

The best case for a pusher that i've seen is the late Alex Strojnik's Laminar Magic, but that was really a single-point design.

I saw Rutan speak at Oshkosh '80 of a Vari-eze that crashed just a few miles short of Oshkosh. He said that the nose of the plane and the engine hit the tarmac at the same point...the engine going through everything in between. Now, the crash was absolutely unsurvivable in any plane, but that conversation has left a mark.

Thad

Unknown said...

>He said that the nose of the plane and the engine hit >the tarmac at the same point...

Pretty much any plane does that (even with engine on front), planes are not (and can not be) built to survive crashes after nose down dive.

In twin engine aircraft, the engines are in wings, instead of fuselage, and the engine coming out of its compartment does not matter in this type of crash, and the point for either pusher or tractor in terms of safety has no difference.