The Revolution Will Not Be Televised wrote in message ...

And when the Flak threat, which is the main issue we both have with
them in 1943-44, was much higher. If they were usable in 1945, their
main threat in regard to operational altitude was less capable in
1943. Obviously, the fighter threat is the real issue in 1943, but
the Luftwaffe could not afford to treat them like a Circus over the
Pas De Calais, and so their ability to concentrate on them and inflict
heavy attrition at their own leisure would be constrained.

While the amount of flak guns went up it appears the standard
"window" was an effective jammer until the end of the war, so
flak effectiveness seems to have gone down on a per gun
basis from mid 1943. Hence the USAAF's use of it.

I will drop this in since I have not seen it elsewhere,

From the British history Design and Development of Weapons,
M M Postan, D Hay, J D Scott.

It claims there were 4 basic Spitfire airframes which it labels
A, B, C and D

D was the mark 21 onwards,
C was the mark VII, VIII and most griffon marks up to XIX

A was the original which served for the marks I, II, IV. It was
stretched to do the Va, Vb, VI, PR VII and XIII and the Seafire I.

B was the airframe developed from the abortive mark III fighter,
it was used for the Vc, IX and XII, and presumably XVI. The
main change appears to be the "universal" wing.

I doubt this makes a major difference to CoG calculations in the
mark V though. It seems the fighter had quite a tight margin,
the report that for AB186 noting handling was worse with a
Rotol propeller, rather than the standard de Havilland propeller,
they were testing a modified elevator balance.

BR202 (tropical Vc) was tried with a 29 gallon rear fuselage tank,
requiring repositioning of the water tank, oxygen bottle and the
R3002 radio, the certificate of design was issued on 7th July 1942
along with official approval.

Some Spitfire Vs were flown from England to Gibraltar in early
1942, January I think, 5.5 hour flight.

Seen Morgan and Shacklady, page 150 in my copy, map of
Spitfire V range with extra fuel arrangements?

Ferry, full overload tanks, 5 minutes take off, cruise at 240 mph
with 20% fuel reserve, reinforcing radius 1140 miles.

Escort, 5 minute take off, 10 minute climb, 15 minutes maximum
power, remainder cruise at 240 mph, radius 540 miles. Given
the need for higher cruise and problems of slower bombers this
still should have meant around the German border at least. Note
the extra range required a bigger oil tank, from 7.5 or 8.5 to 14.4
gallons. Note the deeper noses on the PR versions. The book
does not state what fuel tankage is being used.

In early 1942 Sholto-Douglas was asking for tanks of up to 30
gallons in the wings. Fighter Command had realised it needed
more range to fight over France, it does not seem to have come
up with the idea it should try for Germany. Apparently with drop
tanks the Typhoon could make the German border. The RAF
in Ceylon recognised the need for longer range as well, noting
the Japanese capabilities.

Fuel tankage according to Morgan and Shacklady,

VIII 47 (upper) + 49 (lower) in front fuselage + 2 x14 (1 in each wing)
IX 48 (upper) + 37 (lower) in front fuselage (same as V) later 2x18
(1 in each wing) and 33 or 41 in rear fuselage.
XIV 36 (upper) + 48 (lower) in front fuselage + 2x12.75 (1 in each wing)
XVIII 36 (upper) +48 (lower) in front fuselage + 2x12.75 (1 in each wing)
+2x33 in rear fuselage. By the looks of it the FR version a camera
replaced one of the rear fuselage tanks.

The PR X, 47 (upper) + 48.5 (lower) in front fuselage + 2x66 (1 in each
wing) the cameras were in the rear fuselage.

The text mentions the mark IXe weights with 66 gallon rear tank.
As far as I can tell the idea of major Spitfire modifications keeps
running into the problem that until the P-47 was proven the allies
did not have another fighter that could be considered a match
for the Fw190A and Bf109G, hence the rush for the IX instead
of awaiting the mark VIII. The middle east had to do without
Spitfires until early/mid 1942 (Malta then Egypt), the major
withdrawal of mark IXs from fighter command to the squadrons
in Tunisia in early 1943.

As far as I can see the long range Spitfire requires a Merlin
60 series to be competitive, and for the forward CG, wing
fuel tanks, preferably a cut down rear fuselage for weight
reasons, a bigger tail (at least XIV size) and the rear fuselage
tanks, taking the best from the above you end up with 47 + 49
in the front fuselage 2 x 18 (1 in each wing) and 66 gallons in
the rear fuselage, total 198 gallons. Then add external tanks,
and remembering these are imperial gallons. Vickers
apparently had a proposal for 197 gallons of internal fuel, in
the above configuration. This would give a still air range of
around 1,400 miles. The mark IX ML186 was apparently
trialed in January 1945 with a 66 gallon rear tank and maybe
some of the other tanks, take of speed was 78 mph, longitudinal
stability started at 140 mph, flaps and undercarriage down
tended to make the aircraft stable again. The pilot had to have
his hand on the control stick at all times, cruising at 245 mph
at 12,000 feet meant the aircraft could not be trimmed. After
35 gallons of fuel from the rear tank had been burnt the aircraft
"stabilised".

Spitfire output by Supermarine works, (from a graph in Design
and Development of Weapons, which goes from January 1941
to December 1943, with a small quota of error when adding the
totals up)

columns are date / total for month / IV / VII / VIII / IX / XI / XII / XIV /
Seafire. There was 1 mark VI in November 1942.

Nov-42 112 / 3 / 3 / 6 / 58 / 3 / 1 / 0 / 37
Dec-42 106 / 5 / 2 / 8 / 54 / 8 / 2 / 0 / 27
Jan-43 130 / 4 / 4 / 10 / 63 / 10 / 3 / 0 / 36
Feb-43 114 / 2 / 1 / 20 / 48 / 11 / 6 / 0 / 26
Mar-43 117 / 0 / 4 / 40 / 24 / 12 / 20 / 0 / 17
Apr-43 98 / 0 / 4 / 46 / 10 / 8 / 17 / 0 / 13
May-43 126 / 0 / 10 / 43 / 18 / 27 / 0 / 28 / 0
Jun-43 110 / 0 / 7 / 76 / 6 / 14 / 7 / 0 / 0
Jul-43 105 / 0 / 5 / 81 / 0 / 12 / 7 / 0 / 0
Aug-43 124 / 0 / 5 / 96 / 0 / 19 / 4 / 0 / 0
Sep-43 133 / 0 / 5 / 104 / 0 / 20 / 4 / 0 / 0
Oct-43 133 / 0 / 3 / 108 / 0 / 19 / 0 / 3 / 0
Nov-43 125 / 0 / 8 / 88 / 0 / 19 / 0 / 10 / 0
Dec-43 124 / 0 / 16 / 76 / 0 / 22 / 0 / 10 / 0

Geoffrey Sinclair
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