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Old 07-13-2020, 04:57 AM   #891
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Join Date: Jan 2018
Location: Tocumwal, NSW, Australia
Posts: 1,156
Default Re: tell a Model A related story

Question asked of me.

My friend Deluxe asks if any aeroplanes were built with contra rotating engines. Yes, some were but before I respond, bear in mind my knowledge is with civil aeroplanes and almost entirely with cropdusters. I have no knowledge of military or experimental aeroplanes

Piper aircraft built a twin Comanchie with these contrarotating engines. The objective was to reduce asymmetric effect if one engine fails. The good engine pulls towards the failed engine- thus asymmetric. This takes very considerable power to counter and hold the aeroplane straight or approximately straight. The down going blade produces more pull than the upgoing blade. So, the closer the down blade is to the centre of the aeroplane the less sideways pull or yaw, the aeroplane has to overcome.
I am sure there are more aeroplanes with contra-rotating engines/propellers.

The English Navy Fairy Gannet has contrarotating props in the centre line. I would think this would be a mechanical nightmare.

There are many pilots who subscribe to this forum as well as engineers and maybe designers as well. I think they would have knowledge and skill in this field. They may care to add to the above.
The pictures are the two aeroplanes I spoke of above: the Twin Comanchie and Fairy Gannett.
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