Oleg - Spitfire Cockpit.

[BOBC]

Biggs...Hey BOBC, slightly off topic but do you know what version of propeller we should be seeing in SOW? the deHavilland 2- pitch or the Rotol Constant speed.

I thought in the early part of 1940 most of the spits were fitted with de Havilland but by the late spring they were producing them with the better performing constant speed.

I asked Oleg a while ago but I dont think I got a definitive answer.

Information I have managed to obtain now (and thanks to those suppliers of same, summarised says:-
By Dunkirk almost all of the RAF home fighter force had De Havilland variable pitch (2 settings, three blader). According to Al Deere, in "Nine Lives," 54 Squadron were trialling Rotol constant-speed props, during the Dunkirk evacuation
The Rotol (hydraulic) constant speed was introduced for production of MkII Spits and retrofitted to MkI from June 1940. It's a manual constant speed (ie. fully variable )
The constant-speed propeller (same propeller but with internal adjustments) modifications were carried out in the field from June 26th to August 15th on 1,051 Spits and Hurris by De Havilland engineers and squadron staff as the further performance advantages were obvious by then over the 2 speed props..
de-Havilland propellers were licence-built Hamilton designs, Rotol being a home-designed product.
The Hamilton Standard is electric and less prone to overspeeding in dives; it came later.
Rotol were a bit further ahead with their constand speed propeller developments during the first year of the war.
The Rotol electric props utilised the Curtiss Electric-designed propeller pitch change mechanism for their electric props, presumably as an alternative to hyydraulic should any serious production problems arrive with the hydraulic types.

BOBC

[KG26_Alpha]

Aeroplane and Armament Experimental Establishment
Boscombe Down
30 July 1940

Comparison of Performance of Rotol and DH Airscrews on Spitfire

Both the aircraft are similar externally and are fitted with bullet proof windscreen and armour plating over the tank, etc.

Aircraft R6774 is fitted with DH airscrew and N3171 with Rotol airscrew.

It will be noted that these aircraft are about 12 miles an hour down in speed against the previously tested K9793, but the relative comparison remains. This loss in speed is accounted for, by 6 miles an hour for the bullet proof windscreen and 6 miles an hour due to loss in engine power.

Level Speed miles per hour.

Aeroplane Altitude Feet

14000 16000 Max. speed 20000 22000
R6774 342 349 355 @ 17,800' 350 341
N3171 336 343 354 @ 18,900' 354 352

The above tests were all carried out using 87 octane fuel with boost limited to +6.25 lbs./sq.in. Climb figures were achieved using the 2600 rpm 1/2 hour climb limit. By the Battle of Britain all operational squadrons had changed over to 100 octane fuel and the engine limits on the Spitfires had been increased to +12 lbs./sq.in. 3,000 rpm with 1/2 hour climb limit increased to 2850 - 3000 rpm. Royal Aircraft Establishment figures for a Spitfire I using +12 lbs/sq. in. boost are 314 mph at Sea Level and 359 mph at a full throttle height of 11,500 feet.

From

http://www.spitfireperformance.com/spitfire-I.html

[Skoshi Tiger]

Also that the CSU cut still air take off distance to 225yrds vs about 320 and increased rate of climb compared to the 2 pitch propellers.

[BOBC]

Do we know if Oleg and team have corrected the Mk2/5 hybrid cockpit to a Mk1 Bob period spit yet ? ...and if the observations have in fact ever reached them ?
I just cant see how what is the most awaited sim can have us in a later war cockpit.

BOBC

[major_setback]

I don't think there will be any major changes this close to release. And I don't think it is reasonable to expect any.