Airscrew manufacture

Mike, we should start some kind of society – I agree, props never got the attention they deserved – even during the design stage.

Enormous amounts of time and energy were spent refining engine designs to get maybe a couple more horsepower here or there with every tweak – half a mile an hour’s worth of new valve seat would be incorporated with alacrity.. and then the aircraft designer would almost chuck any old prop on the front. As long as it fell within a power range and didn’t touch the ground, it would – and usually did – do. The fact that the wrong choice could drain 100HP’s worth of thrust from the system didn’t seem worthy of consideration, and curiously only rarely has since. It is only now that Hercules propellers in Gloucestershire are showing GA users the enormous difference the right prop makes.

Serious amounts of work went into designing blade profiles and aerofoils on both sides of the pond and even more (as shown in the video) precision-engineering these within an inch (or a Thou) of their lives. This was then completely ignored – as long as it goes round the right way, it could all be forgotten.

A classic example is the Whirlwind – the bleedin obvious (when you see it) problem with the wrong blades wasn’t seen, to the point where it ‘must’ have been some unspecified and untraceable problem with the engines – and that is what passed into the record. I am uncovering several more cases like this.

I enjoyed that!

Although a British film, taken in a British factory of a British-assembled airscrew for an RAF aircraft the propeller, almost certainly, will be a Hamilton-Standard-built unit built by, and imported from, the US.

The design is the classic 23-E-50 (or 23EX in UK service) of which hundreds of thousand were built, many of which are still in use today. A superb design, beautifully made and a superb example of American design quality and mass-production expertise.

They were imported all through the war as well as being produced, under licence, by de-Havilland. So widely used were they that most UK types had them fitted such as Lancaster, Stirling, Mosquito, Hurricane and many a Halifax as well as lots of other types. A truly superb bit of engineering, very apparent in this excellent, if rather slow, film.

Anon.

Edit: Needless to say, but this hub (with the appropriate blades to suit the application) was used in very many US aircraft too. It can be recognisable as that fitted to B-17 (12,500 built x 4), B-24 (17,000 built x 4), as well as Hellcat, Corsair, C-47 (10,000+ built x 2), C-54, A-26, plus many, many more lower production types. A truly successful and superbly engineered product.

I like props and believe them to be a woefully undersung part of the success of the Allies in WW2.

Anon.

Thank you for posting this Link – very interesting how cool and calm the mechanics do their job. How could they produce hundreds of thousands of airscrews