In article ,
Guy Alcala writes:
Peter Stickney wrote:
That yesterday seemed to be my day for being obfuscative.
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.
Ah, sorry. Don't forget that I've lagged a bit here. I was just
following up on Gavin's question about squeexzing more fuel into a Mk
V. Since the engine's a lot lighter, they don't have as much moment
on the Good Side of the CG balance, and there isn't any good space
insude a Mk V for a substantial amount of fuel. The 29 Imp. Gallon
tank is all that you can get an have an airplane that isn't too
dangerous for the 1943 RAF. In irder to geep that influence to a
minimum, a medium-sized drop tank would also be necessary, to keep the
CG where it ought to be. My point about the radios was that the early
Brit TR sets were, when you include their rectifiers * transformers,
about 200# of load, and quite a bit of space. If that 200# could be
cut in half, that's 15 Imperial Gallons of fuel that yo could squeeze
in.
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
Yep. Yhe Mk IX's got it nearly on the CG datum, though.
I'll get the tracing paper & rulers & see if I can come up with som
emore detail.
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.
Which is about enough to climb about 5,000' with a Griffon Spit.
--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster