[woofa.express]

This follows the previous story. Number 891. Well it took only a little more than an hour before I received an email which you can read in the next paragraph.. What I do know is when I pull back on the pole the trees get smaller and when I push forward the trees get bigger. That's about the guts of it.

Gary,
To that, add Avro Shackleton, Bristol Brabazon, Westland Wyvern, Griffon powered Spitfire, Saunders-Roe Princess, all from UK, then Griffon-powered Mustang, several Curtiss models, Convair “Pogo”, from the US, and the Russian Antonov AN-22, Tupolev Bear bomber, and others. Some of these are still current. I was in Russia once when a Tupolev swept wing propeller bomber flew over at high altitude – a very different sound. Check Youtube. Some helicopters, lacking a tail rotor, have 2 contra rotating rotor blades. Contra means complex gearbox!

I think you’d call the Piper PA-39 TwinCom as having counter rotating propellers (not contra), as in Piper Chieftain, PA-602/700 Aerostar, Seneca, Cessna Crusader, etc. The new Airbus A400 military transport has 4 paired counter rotating turbine engines.
Aero engineers and designers have had highly imaginative design philosophies throughout the short history of the air.
Cam

I responded with the following statement.

Thanks Cam. As I said I have limited knowledge of aeroplanes outside of cropdusters. Well I was wrong. It appears I have extremely limited knowledge outside of cropdusters.