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DAVIDICUS said:RG,
Why would the Spitfire hold an advantage over 30K? I would have thought that the Bearcat would have waxed the Spitfire at any altitude.
And which Spitfire was the best model to become operational prior to 1946? I noticed that you mentioned the XIV.
Soren said:RG the Spit Mk.21 had an intirely new WING for christs sake !! It was thicker, stronger, and had an even better armament (4x20mm Hisp's)
The new wing was similar in plan, but was stronger, carried more fuel, housed a longer landing gear (which allowed a larger diameter propeller), and carried four 20mm cannon.
http://www.chuckhawks.com/spitfire.htm
Supermarine 368 Spitfire 21 - NACA 2213 (root), NACA 2209.4 (tip)
Vought V-166 F4U Corsair - NACA 23015 (root), NACA 23009 (tip)
http://www.aae.uiuc.edu/m-selig/ads/aircraft.html
Soren said:The Spit Mk.21 would most likely out-turn the Bearcat, aswell as out-climb it ! (Even the Mk.XIV has an initial climb rate of over 5,000ft/min !)
Soren said:And about the test with the F6F and Spit V, Source please ?! British tests showed that the Spit Mk.IX turned just as well as the Spit Mk.V, while the Mk.XIV turned just as well as the Mk.IX !!
So there goes your theory about the Spit Mk.XIV not turning as well as the Spit Mk.V !
While I'm looking for those tests, perhaps you can provide a reference to the Spit IX turning as well as the Spit V, or the Spit XIV turning as well as the Spit IX (which implies it turned as well as the V)? Everything I've ever read disputes this!
Stronger yes... thicker no.
RG_Lunatic said:Can you give the source of that data please?
DAVIDICUS said:Didn't any of the Bearcats that became operational prior to '46 have 4x20mm's?
Soren said:RG_Lunatic said:Can you give the source of that data please?
Take a look at the 4th Fighter-group site.
--------------------------------------
And about the Spit Mk.21:
1. Introduction.
This report summarizes the results obtained on the prototype Mark 21 fitted with a Griffon 61 engine.
2. Summary of Results
At an all up weight of 9000 lb. and wtih combat rating of 2750 r.p.m. and 18 lb. boost:-
(a) Maximum level speed 455 m.p.h. at 25,600 ft.
(b) Maximum rate of climb 4800 Ft./Min. at 7700 ft.
(c) Time to 30,000 ft. 7.85 mins.
(d) Service ceiling 42,800 ft.
(e) Coolant and oil suitabilities: Full tropical under combat climb conditions.
Aeroplane and Armament Experimental Establishment
Boscombe Down
10 October 1945
Spitfire F. Mk. 21 LA.187
(Griffon 61)
Climb and Level Speed Trials
Summary.
...........Climb and level speed performance trials have been completed on this aircraft, the first production Spitfire 21. The salient results were as follows :-
Rate of climb at full throttle height, MS gear, +21 lb/sq.in., 2750 rpm = 4440 ft/min. at 4900 ft.
" MS gear, +9 lb/sq.in., 2600 rpm = 2740 ft/min. at 14,200 ft.
" FS gear, +21 lb/sq.in., 2750 rpm = 3615 ft/min at 19,200 ft.
" FS gear, +9 lb/sq.in., 2600 rpm = 2125 ft/min. at 29,000 ft.
Estimated service ceiling, 2750 rpm = 43,400 ft.
" 2600 rpm = 42,400 ft.
Combat level speed (+21 lb/sq.in., 2750 rpm) = * 406 mph at MS gear full throttle height (7000) ft.
* 442 mph at FS gear full throttle height (21,800 ft.)
446 mph at FS gear full throttle height (22,600) ft.)
For the full report click HERE
http://www.spitfireperformance.com/spit21.html
Soren said:RG Im really beginning to question your credibility as your Climb info for the Spit Mk.21 is just flat wrong, and must have been "Home made"
An Air Ministry document from 29.10.43 details the protocol to use in arriving at performance figures for aircraft:
NOTE ON THE USE OF PERFORMANCE ESTIMATES
1. There are 4 main stages in the evolution of performance for a new aircraft:-
(1) Original Estimate - based on drawings and expected engine powers.
(2) Flight Tests - Performance of actual aircraft - (a) Prototype, (b) Production, when built
(3) Provisional Performance Curves - Adjustments of (1) in view of (2)(a).
(4) Final Performance Curves - Based on (2)(b) and subject to variation with the condtion of the aircraft.
2. The limits within which the Stage (1) estimate can be guaranteed depend on whether the new aircraft is -
(i) A development of an established type whose characteristics are well known (e.g. Spitfire XIV); or
(ii) A new type, about which little or no confirmed information is available, (e.g. F2/43, with Centaurus engine).
(Note:- The addition of new factors, e.g. Contra-rotating props. to an aircraft in Category (i) would probably transfer it to Category (ii).)
3. With "Development" aircraft, original estimates should be accurate to within 1-2% in speed, and 50-100 ft./min. in rate of climb. With "New Type" aircraft, however, the error might be up to 6-7% in speed, and 200-250 ft./min. in climb.
4. Flight Test figures, by themselves, should be treated with considerable reserve, since they may be obtained under non-standard conditions, and the aircraft flown may differ from production machine.
5. From the prototype trials, Provisional Performance Curves can be obtained, modifying them, if necessary, to allow for the effect of the difference between the prototype and production machine.
6. Only when trials with representative production machines have been carried out under known conditions can the Final figures be issued. These figures then represent the performance expected of an average production machine of this type.
7. Any particular machine off the production line, however, may vary from the average in top speed and climb because of differences in engine power and general finish. The usual variation for single-engined fighters is up to 3% in top speed, and 150-200 ft./min. in rate of climb; heavy bombers vary up to 4% in top speed, and 150-200 ft./min. in climb. (...)
http://www.spitfireperformance.com/
However, all F8F's had universal gunbays, and could fit either .50's or M3 20mm.
Soren you can just go to hell!
However, unlike you who simply chose to present the best data available as fact I read through all of it
Now I want to see that data showing the Spit V, IX, and XIV all turned equally well.
You realize that if this is true it throws all your wingloading arguments right out the window, as all 3 planes had exactly the same wings but weights of 6500 lbs, 7500 lbs, and 8500 lbs, respectively
the lancaster kicks ass said:However, all F8F's had universal gunbays, and could fit either .50's or M3 20mm.
which to you means of course that they all carried 20mm and even though you don't know if they used 20mm before 1946 the fact that the gun bay could take it, in your increasingly annoying eyes this means that they did carry 20mm the whole time..........
Soren said:Soren you can just go to hell!
And you expect to be taken seriusly when saying such rubbish ? RG Im disappointed !
Soren said:However, unlike you who simply chose to present the best data available as fact I read through all of it
Oh really, well then you just "forgot" this part or what ?:
5.1 Due to a slight inaccuracy in the adjustment of the boost control the tests were not done in all cases at exactly the nominal boost. It is calculated that altering the boost on test to the nominal value would have increased the normal rate of climb below full throttle height by about 70 ft/min. in MS gear (boost 0.4 lb/sq.in. too low) and 100 ft/min. in FS gear (boost 0.7 lb/sq.in. too low).
5.1 Due to a slight inaccuracy in the adjustment of the boost control the tests were not done in all cases at exactly the nominal boost. It is calculated that altering the boost on test to the nominal value would have increased the normal rate of climb below full throttle height by about 70 ft/min. in MS gear (boost 0.4 lb/sq.in. too low) and 100 ft/min. in FS gear (boost 0.7 lb/sq.in. too low).
.....The level speed and rate of climb at combat rating would not have been affected appreciably.
http://www.spitfireperformance.com/la187.html
Soren said:Now I want to see that data showing the Spit V, IX, and XIV all turned equally well.
RG I already gave you them !!
Soren said:Now I want to see that Spit V and F6F test of yours !
Soren said:You realize that if this is true it throws all your wingloading arguments right out the window, as all 3 planes had exactly the same wings but weights of 6500 lbs, 7500 lbs, and 8500 lbs, respectively
Your actually convinced that its all about the Wing-loading as to how well a plane turns ?!!
RG what about Power-loading, Wing-aspect-ratio, center of gravity etc etc !