On Sat, 23 Aug 2003 04:01:24 GMT, Guy Alcala
wrote:

[tank plumbing]

I'm not sure that accords with RAF standards. I finally got my hands on Price, and reading the specs for
F.7/30, Part 2(B) "Fuel and Oil Systems," I'm not sure that would be allowable. OTOH, the spec may have
changed.

The re-armament sepcs were definately modified as a result of combat
experience. The external slipper tanks which appeared in 1941 were
unforseen in the original contracts, just like the need for bomb
shackles and so on. I should just scan the Pilots Note's and send
them to you.

What provokes this at the strategic and political level?

Nothing. As explained in my other post, this was originally a 'what if' thought experiment from ACM
Kramer.

Fair enough. But from my perspective it's more fun to ground this in
a believeable context for a departure from the historical policy.

[Spit range]

at least 250-300 mile radius would seem doable when carrying a 90 gal. tank.
What gives? The 85 gallon Mk. IX will be somewhat worse, but not all that much.

The RAF were very conservative when planning fuel usage on operations.
They gave a Spit LF IX a range of 365 miles on internal fuel, or 785
with a 90 gallon external tank. Yet the figures the planners for
Cirucs ops used were 100 miles radius for big formations of Spit V/IXs
and only 150 miles for "long-range" [external tank] profiles*.

[* PRO AIR 14/407 "Co-ordinated Operations, Bombers & Fighters
(Circus ops) Vol.2, 78B: Fighter Command Operational instruction
13/1943 - "Operational Endurance of Fighters", Appendix A. This gives
the following breakdown:

Type long sea-crossing/short-sea crossing/large formation

Spit V/IX short-range 300m/240m/100m
Spit V/IX long-range 420m/300m/150m]

Using these figures, actual deployment in regard to operational ranges
used on operations seems to be conservative: after D-Day, Spit V
units based on 11 Group bases and ALGs were sweeping from Manston to
Verdun on 90-gallon tanks, and Spit IX wings based on similar ALGs
were escorting and sweeping to Paris and back. This was on a tankage
profile that was identical to that available in 1942.

The high-altitude Circus ops of 1941-42 did involve large and
complicated wing assemblies over the southern coast of England at high
altitude, which consumed time and fuel, and involved formating on
slower bomber formations with zig-zag courses which all suppressed
available range. Things did change in 1942-43, with low-altitude
assemblies and mid-Channel climbs, as well as increasing external
tankage. Nobody seems to have put two and two together and actually
acknowledged the fact that they could actually escort a bomber force
all the way to the German border and back with sequential waves of
Spitfire escorts covering different sections of the route.

In this respect, the USAAF benefitted from a strategic bombing policy
which pulled the fighters out in support. British escorted bomber
operations didn't dicate fighter operational deployment in the same
manner.

The conservative figures used for Group planners (i.e. understating
the available fuel to avoid disaters like 133 Sqn's escort to Morlaix
in September 1942) leave a big difference between the known individual
range figures they used. BTW, those figures for the Mustang III from
the same source (individual a/c stats) give it a range of 690 miles on
internal fuel, or 1180 with a 90 gallon tank, while the planning
figure for short sea-crossing, small number of a/c range (the best
range figure) gives it just 600 miles. Speculatively using the same
divisor for large formations on a big-sea crossing would indicate a
contemplated range for operational planning purposes of only 200
miles.

Gavin Bailey

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