Allied AFs in 1943: realistic options for long range fighters?

[Mike Williams]

USAAF Materiel Division modified a couple of Spitfire IXs for long range:

No reason I can see that this couldn't be done in 1943 as well.

 

[tomo pauk]

Many thanks, Mike

Total fuel tankage is listed at 345 USG. Were the fuel tanks of 75 USG variety? That would leave 195 USG of internal fuel, or cca 155 imp gals?

 

[wuzak]

So, in 1943 the Spitfire IX could have provided a decently long range, had the modifications been performed?

Moving into 1944, the P-51B was being delivered in numbers, and that solved the long range issue.

The Spitfire XIV was also being delivered late 1943/early 1944. How much extra internal/external fuel would be required to allow the XIV to escort as far as Berlin?

According to Wiki the XIV had 109.5 UKG fuel, and, apart from the first 25, the XIX had 256 UKG. Where was that extra fuel held? I am assuming that this was in the leading edge, precluding the use of wing guns?

And, if Spitfire XIVs could get to Berlin and back, would the AAF be interested in using them, or would they prefer to just continue with their P-51Bs?

 

[tomo pauk]

For the late war Spitfires there was a possibility to have rear fuel tanks installed, some 65-70 imp gals there (depending whether the rear fuselage was cut down or not). Kindly provided by our fellow member, glider:

 

[tomo pauk]

One wonders how easy/difficult would it be to attach the 170 imp gal (212 USG) slipper tank to the P-47. Contrary to that tank, the early P-47 belly tank (200 USG) was troublesome item to use. The historically used 108 USG drop tank was enabling the combat/escort radius up to 375 miles.

 

[Juha]

From an old thread - Longest Spitfire raid of WWII. (http://www.ww2aircraft.net/forum/aviation/longest-spitfire-raid-wwii-16182.html)

Wildcat 12-30-2008 05:57 AM
Longest Spitfire raid of WWII.

On the 27th of Nov 1944, five spitfires from No. 549 sqn RAF and 2 spitfires from No.1 Fighter Wing, RAAF in conjuction with 4 B-25's from No. 2 sqn RAAF plus an ASR Catalina, attacked and destroyed a Japanese radar station at Cape Lore on Portuguese Timor. The raid was a round trip of some 850 miles taking 4.5 hours. The Spitfires were first to attack carrying out strafing runs on the installations resulting in the radar tower being destroyed. The B-25's then destroyed the remaining buildings once the spitfires were clear.
The spitfire pilots flying Mk.VIII's, were -...

Juha 12-30-2008 11:15 AM

...Longest Spitfire escort mission in ETO I'm aware was that made by 131 Sqn on 11 Aug 44 to La Pallice, 690mls and took 3 hours 50 min. They were flying Spit VIIs. That was more or less max possible for those Mk VIIs, they didn't have much fuel for combat but Brits calculated that their mere presence would prevent LW attacks on the bombers.

Juha

 

[Juha]

... the XIX had 256 UKG. Where was that extra fuel held? I am assuming that this was in the leading edge, precluding the use of wing guns?
...

PR XIX had the normal fuselage tanks at the front of the cockpit plus wet leading edge, it was unarmed photo recon plane.

Juha

 

[Glider]

Its worth remembering that the first Spitfires with rear tanks were PR versions in 1940. With a bit of imagination someone might have done the same with versions from the Mk V onwards.
These early tanks were 30 gallon tanks but every little helps

 

[Edgar Brooks]

USAAF Materiel Division modified a couple of Spitfire IXs for long range:
No reason I can see that this couldn't be done in 1943 as well.

You would, if you had to go into combat; to fit the wing tanks, three ribs were removed from the leading edge "D" box, and the Air Ministry were extremely sceptical that the added strengthening was sufficient to keep the integrity of the wing intact.
Also the mechanisms for the wing droptanks extended inside the outer cannon bay, almost certainly precluding any chance of conversion to the "E" wing.

 

[Glider]

That wouldn't be an issue with the extended range Mk IX as modified in the UK. This relied more on the internal fuel than the US conversion and the external tanks were no more than often used in combat. So the option still stands.

A side observation, Malta used Mk V spits with 2 x 45 gallon DT under the Fuselage as long range fighters. The tanks were taken off Hurricanes which had flown to the Island. There must have been some scope for developing this idea had someone put their mind to it

 

[RCAFson]

USAAF Materiel Division modified a couple of Spitfire IXs for long range:



No reason I can see that this couldn't be done in 1943 as well.

Wow!

If the US had built the Spit under license they could have been using these instead of the Mustang and/or the T-Bolt.

 

[Hop]

Total fuel tankage is listed at 345 USG. Were the fuel tanks of 75 USG variety? That would leave 195 USG of internal fuel, or cca 155 imp gals?

Yes. According to Price the extra fuel tanks fitted were:

43 gallons rear fuselage
2 x 16 gallon wing leading edge
2 x 62 gallon drop tanks
Total fuel - 285 gallons

Those are imp gallons. That means the aircraft was fitted with the original 86 gallon main fuel tank, not the 96 gallon type that was fitted later (and could have been fitted from the start, if specified)

You would, if you had to go into combat; to fit the wing tanks, three ribs were removed from the leading edge "D" box, and the Air Ministry were extremely sceptical that the added strengthening was sufficient to keep the integrity of the wing intact.

That shouldn't have been an issue if the planes were being modified on a large scale. After all, the Spitfire VII and VIII, and later Griffon versions, had 2 14 gallon tanks in the same position.

Also the mechanisms for the wing droptanks extended inside the outer cannon bay, almost certainly precluding any chance of conversion to the "E" wing.

I don't think wing fuel tanks were even necessary. The US conversion added 124 gallons in 2 wing drop tanks, but there was nothing precluding a single tank of that size (or larger) being fitted under the fuselage. There was actually a 170 gallon "torpedo" style tank available for the Spitfire later in the war, although it was rarely used.

 

[tomo pauk]

Thanks, hop

I don't think wing fuel tanks were even necessary. The US conversion added 124 gallons in 2 wing drop tanks, but there was nothing precluding a single tank of that size (or larger) being fitted under the fuselage. There was actually a 170 gallon "torpedo" style tank available for the Spitfire later in the war, although it was rarely used.

A single belly tank, namely the 150 USG (124 imp gal) tank from the P-38s should fit nicely under belly of the Spitfire - that should beeven an easier thing to do, rather than to make them carry the tanks under wing. Already the Spitfire V was capable to carry the 170 IG slipper tank anyway.

 

[Shortround6]

In most of the operations using the 170 gallon slipper tank the Spitfires used an enlarged oil tank ( as did many of the PR Spitfires).

On the Malta flights the planes either carried reduced armament or no armament and were armed upon arrival. Oil tanks may have been changed back too.

More could have been done to improve the Spitfires range but it was never going to be a P-51. Photo recon planes often depended on going high and fast in straight lines, not twisting and turning at high "G" loads to escape. They could fly (and did fly) with CGs limits that would prove fatal to aircraft trying to perform high "G" maneuvers.

Combat radius is determined by the amount of fuel on board AFTER combat, not the before combat.

Standard procedure for both P-51s and Spitfires with rear fuselage tanks was to use a considerable portion of it BEFORE using the external drop tank fuel. Even early P-40s considered the rear fuselage tank as an "overload" tank to be used before combat was joined.

Combat radius of a Spitfire would include the fuselage tanks (the later larger ones), the wing leading edge tanks used in the MK VIII and others and perhaps a certain amount in
a rear fuselage tank but certainly NOT anywhere near 50-60 gallons. Perhaps 15-25? perhaps not?
Now subtract 5 minutes at combat power, 15-20 minutes at max continuous power, 20-30 minutes at minimum fuel consumption as a reserve once you get back to England and you have the fuel available for cruising on the return flight after combat. Pick a reasonable cruising speed for use over enemy territory were you could be bounced again, no 170-210mph economical cruise speeds allowed

The amount of fuel left X the fuel consumption at the desired cruise speed used for eggressing the combat zone (continental Europe?) defines the combat radius, it is immaterial how much fuel you lug on the way in.

 

[tomo pauk]

IIRC the P-51 pilots were to take off on fuselage tank (85 USG), expand a half of it, then switch to external fuel? That would leave some 40-45 USG (or 32-35 imp gals) prior using the drop tanks.
I agree that it would be very hard* to make a P-51 from a Spit (range-wise), but a Spit VIII with 30 imp gals in the rear fus. tank would be very close. And feasible/available in early 1943, the best quality of the modification had it been done.

*but not impossible, see Yak-9D/DD

 

[tomo pauk]

Was there a way to 'sneak in' the F4U-1 in the ETO as a long range fighter? Maybe under RAF's guise?
At 21500 ft and with 360 gals of internal fuel, the endurance was 5 hrs 20 mins at 75% of the high speed - 1600 miles? (F4U Performance Trials). And then strap on a drop tank...

 

[gjs238]

Would these be for B-14/24 escort duty?

 

[tomo pauk]

A general-purpose fighter. So even an escort fighter.

 

[Glider]

A lot of thought has gone into adding fuel to the Spitfire, but the Typhoon had a better range than the standard Spitfire, could easily carry the weight of drop tanks on the wings. Granted it wasn't great at altitude but a) it wasn't as bad as some people assume and b) RAF bombers didn't fly that high anyway.

Do people think that something could have been done with the Tiffy?

 

[tomo pauk]

The performance was there to compete vs. LW opposition. Was Typhoon ever cleared to carry more than 2 x 500 lbs bombs (alternativelly, 2 x 90 imp gals) under wings? As for internal fuel, the Tempest was modified to carry additional 30 gals over the standard 162 imp gals - wonder if someone has more data about the mod?
Typhoon data sheet shows 610 miles on internal fuel (most economical cruise, or 490 miles on max weak mixture) , once the 32 IG are allowed for TO and climb to 15 kft. Every 5 min on combat power subtracts 75 or 60 miles. So 3 x 5 min on combat power makes the 'return range' of 385 or 310 miles. We need to find the way to install another, say, 40 IG into the plane. In wing leading edge, perhaps - all the way from fuselage to cannons.