Warbird Information Exchange

<Good man, we want corrections......

Ok I think this is where we are at this point>


#12 is an Allison V-1710 as used in the P-38. Note the picture on the stand just to the left of the engine

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It's what you learn after you think you know it all, that counts.

The one bladed props were made by a company named Everal or something like that. In theory a one bladed prop is the most aerodymanically efficient, but it puts an asymetric load on the thrust bearing and wears them out, so didn't work out in practice. Note the counterweight built into the stub end for balancing.

Interesting.

On the 'odd props' front, the Supermarine Sea Otter prototype was fitted with a 'Scissor' type four bladed prop, where the two sets of two blades weren't at 90 degrees to each other, as normal, but closer. This was to enable the aircraft to be a couple of feet shorter in height so it would fit in the RN's Cruiser hangars.



As it was effectively redundant in this role, they reverted to a more normal three bladed prop.

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James K

"Switch on the underwater landing lights"
Emilio Largo, Thunderball.

www.VintageAeroWriter.com

Thank you James, I wondered what the reasoning was behind that idea.

This might be a good thread to post a pic of that engine you found in the Science Museum a few years ago.

It appears the British were fond of "stacking" propellers as evidenced by the wonderful H.P. 42.....





Actually, don't all diametrically opposed blades apply asymetrical loads on the propshaft on all attitudes other than perfect trim cruise? IE: during climbout, due to one blade ascending and the other descending, the blades will have different angles of attack (ascending has less and descending greater).