Peter Stickney wrote:

In article ,
(The Revolution Will Not Be Televised) writes:
On 2 Sep 2003 21:17:46 -0700, (Guy alcala) wrote:

snip

Vader states that the Mk VIIIs had the 'C' wing, which implies that
the Mk. IXs should have been able to be given LE tanks with little
difficulty. I'm under the impression that the substantive changes to
the Mk. VII/VIII were in the fuselage, and except for the tanks the
wings were identical. Does anyone actually KNOW what the
structural/internal changes were from the Mk.V/IX etc. to the Mk.
VII/VIII? We all know about the tail wheel, but there had to be more
than that.

I don't know, but the internal wing spars, which I suspected would
show a difference, appear to be identical between the Vc and the VII,
in which case there should be no problem with deleting the outboard MG
positions in favour of more fuel tank capacity in the Vc-airframed IX.
The shorter-span ailerons appear to be shortened at the wing-tip end.

If there were any fuselage differences, they didn't stop the
late-production IXs getting rear-fuselage tanks anyway.

I'm back.
I've been examining cutaways & measuring & doing sums like a numerate
Dervish, and, while I can't give a definitive answer, I can make the
following observations:
The Mk Vc wing would certainly be suitable for teh leading edge tanks.
I'd go so far as to say that if you were really concerned about volume
in that area, ditching on or both of the .303 guns in each wing would
open up a bunch of space, withoug compromising much in the way of
firepower.

I don't think that's necessary, as the exploded view of a Mk. XIV in Price's
"Spitfi A Documentary History" shows the L.E. tanks are inboard of the
cannon. If tanks could also be installed outboard in place of the MGs, then I'd
probably go for it and accept the somewhat greater vulnerability in combat, but
just getting standard Mk.VIII tankage (123 Imp. Gal. total) would be fine for a
start.

The big deal with the Mk V, and volume behind the cockpit, is that
hteat's where the radios live. Going with a smaller/lighter set would
allow something like teh Mk IX's 29 Imperial Gallon tank.

Not sure what you mean here, as the Mk. VCs were given a 29 Imp. Gal. ferry tank
for the Gib-Malta ferry flights. The later Mk. IX/XVI had 66 Imp. gal. rear
tanks.

Note that
on the Mk IX, the only way to keep the CG acceptable with the aft tank
was to use it only in conjunction with one of the belly tanks.

H'mm, at least with the Mk. XIV, the Cg moves aft when drop tanks are carried,
not forward. See

http://www.fourthfightergroup.com/ea...41weights.html


I
don't really view that as a big deal for an escort fighter, unless you
expect to be engaged immediately at the French Coast. The recommended
tank sequence would be, after takeoff, to use the aft fuselage tank,
then the external tank. (I keep wanting to call that marsupial-looking
excrescence the "carbuncle", for some reason) The 29 Imp Gal tank
should last somewhere between 15 minutes to 1/2 hour, depending on
power settings, so that gets you through form-up, climbout, and pretty
much across the Channel.

Part of the pilot's notes for the F./F.R. XIV are online, and the FR. XIV flight
restrictions contains the following statement:

"On F.R. Mk. XIV a/c it is essential, for reasons of stability, that the rear
fuselage tank should be emptied before flying at altitudes in excess of 15,000
feet." It also states that the fuel tank sequence for the F.R.14 is t/o on main
tanks, switch to rear fuselage tank and empty it, then feed from drop tank. See

http://www.geocities.com/spades53.ge...4_notes_13.jpg

ISTR that this tank is ca. 33 gallons.

Guy