Spitfire flap setting

[Geoff S]

I've just finished re-reading Geoffrey Wellum's 'First Light' and part of the episode in which he was involved in flying his Spitfire off an aircraft carrier to Malta to help the siege puzzles me.

 

It was necessary to set up the aircraft with optimum conditions to take off in the very short distance available.  As it was, they left the deck after being launched up a ramp barely above stall speed.  It was determined that 25% flap was the best compromise between lift and drag.  To achieve that, wooden wedges were inserted by hand (very carefully!) when the flaps were closed to keep them at the right angle.  After take off, the flaps were operated and the wedges dropped out so the flaps could be put away fully.  What puzzles me a bit is that why couldn't the flaps be set to the required angle from the cockpit without the need for the wedges.  Do Spitfire flaps only have 2 positions - full and off?

 

I guess many here have read the book but I'd recommend it highly to anyone who hasn't.  Wellum is only 21 at the end and starts off his RAF career in 1939 at just 19 -  a mere boy and not even eligible to vote at the time. 

[Alan Gorham_]

Spitfires only had 2 flap positions. Fully up and fully down. 

[Geoff S]

That explains the need for the wedges. Thanks.

 

[Jon H]

Yep, Spitfire flaps were pneumatic and you only had two options!

[Paul De Tourtoulon]

Interesting, 25° I will set mine up and see what it does on a model.

[J D 8]

          As land based aircraft with a generous wing area two positions was deemed enough and this even carried over to the Seafire, a limitation of the pneumatic system. Some late mark Seafires had three positions with a cockpit operated take off position added.

[Peter Jenkins]

I had the great privilege of meeting Geoffrey Wellum at a dinner at the RAF Museum in Nov 2008 to celebrate the 90th anniversary of the RAF's founding.  There were a fair number of BoB pilots there many of whom were regulars on TV.  Had I know that Geoffrey Wellum was going to be there, I'd have taken my copy of First Light and asked him to sign it.  I did take the opportunity to thank him and his colleagues for their sacrifices and efforts during the BoB.  He was incredibly modest about his achievements and just said "We were just doing what anyone else would have done".  

 

The actual Schneider Trophy was also there.  It is huge and must have cost a bomb!  Must have been some 6 ft by 4 ft and probably not solid silver but a lot of silver!  There was a security guard in position at all times who dissuaded you from getting too close!  As if anyone could nick something that size and weight without a fork lift!

 

It was an amazing night and included the auction of various items including a painting of the prototype Spitfire flying over Eastleigh airfield showing the yellow RR car that belonged to Mitchell with him standing beside it on the ground.  I don't know how accurate that depiction is as Mitchell was very ill by then and may or may not have been there.  Lord Drayson, who was guest of honour and had been Min DP until the year before, was revealed as the mystery bidder after the successful bid.  I bought the aircraft documentation on the Fairey Delta 2 on behalf of my then employer, QinetiQ.  There were 2 FD2s that were delivered to Boscombe Down for trials.  The world speed record was flown by Peter Twiss with the Farnborough Aerodynamics department providing the photography to record the aircraft passing through the 2 gates - I forget the height but it would have been well above 20,000 ft.  The photos almost missed the aircraft on the second gate on one of the timed runs but close scrutiny showed the nib end of the jet pipe just in the photo with the con trail behind so the FAI accepted it.  After that one aircraft was transferred to RAE Bedford and flew many sorties to calibrate the supersonic wind tunnel so that this tunnel could be used effectively on the design of the Eurofighter Typhoon supersonic aerodynamics.  The other FD2 had a new ogival wing fitted and carried out the sub and supersonic work that fed into the design of Concorde.  I think that shows what great value for money British aviation R&D in the 1950s gave this country.  Pity it has almost stopped!

 

An amazing night that will always remain in my memory - well, until I start losing it that is!