Spitfire Combat Radius (range) evolution, limitations?

[drgondog]

There were no maneuver restrictions on the P-51B/C/D with tank at 60 gallons. In summer 1944, however SOP was 65 gallons in fuse tank unless mission combat radius exceeded 600 miles. Otherwise the practice was to burn 20+ gallons during climb to altitude before switching to externals.

 

[pbehn]

Stable enough for combat - the SOP was to use up half of fuel from rear tank and then switch to drop tanks.
My reasoning is that people here want more range/radius on Spitfire. That does not neccesarily means that it must be good as a Mustang with rear tank. Let's recall that Mustang without rear tank (150 imp gals + 120 imp gals in drop tanks) was good for 470 miles of radius per the demanding USAAF conditions - enough for escort bombers to Magdeburg, Kiel or Stuttgart (where I fly today/tomorrow).
BTW - the Spitfire VII and VIII should be even better than Spitfire IX, they already have front fuel tankage increased to 95 imp gals, and leading edge tanks (25 imp gals total).

I don't disagree, if you take all the possible internal fuel and put it in a Mk VIII then you have maybe 140-150 gallons. The Merlin uses about 150 G/hr at maximum and 50 G/hr on cruise. So you have 20 minutes on combat power and enough for 2 hrs cruise home, but the Spitfire doesn't cruise as far as a Mustang on the same settings so they are 60 miles shorter than a Mustang with the same internal fuel. Then there are the other issues, the British made Mk VII and VIII and sent them to Malta and the far east. What aircraft would they escort? Neither the British nor the USA had suitable bombers for daylight raids until 1943. To have an escort force on a long range mission you need at least three waves, very quickly you need 1000 planes and pilots to mount the campaign. The British had invested massively in night bombing and bombed Cologne with 1000 bombers in May 1942, how do you make a case for more investment in day bombers and fighters to do the same job?

 

[Admiral Beez]

The FAA got the combat range extended with slipper tanks, see bottom of Armoured Aircraft Carriers

 

[Zipper730]

Regarding fuel capacity, if I recall (I should know this but don't), the baseline fuel load was 85 (imp) gallons in the forward fuselage; then for reconnaissance variants: A tank (uncertain as to volume) was added in the rear fuselage (a ballast, which was added to correct for the weight of the constant-speed propeller, was removed for this), then an additional rear tank (unsure as to size), and one under the pilot's seat (which I'm uncertain of what its capacity was, or why it was later removed), of which, at least one of the rear-tanks were carried over onto some of the Mk.V's; The wings would see, on the PR variants: 66 (imperial) gallons in each leading edge, ahead of each of the wing's main-spars; on the VII, VIII, IX: 13 or 14 (imperial) gallons to each leading edge ahead fo the spar.

Anybody have anything more?

 

[Kevin J]

Regarding fuel capacity, if I recall (I should know this but don't), the baseline fuel load was 85 (imp) gallons in the forward fuselage; then for reconnaissance variants: A tank (uncertain as to volume) was added in the rear fuselage (a ballast, which was added to correct for the weight of the constant-speed propeller, was removed for this), then an additional rear tank (unsure as to size), and one under the pilot's seat (which I'm uncertain of what its capacity was, or why it was later removed), of which, at least one of the rear-tanks were carried over onto some of the Mk.V's; The wings would see, on the PR variants: 66 (imperial) gallons in each leading edge, ahead of each of the wing's main-spars; on the VII, VIII, IX: 13 or 14 (imperial) gallons to each leading edge ahead fo the spar.

Anybody have anything more?

AFAIK the maximum fuel load of a Merlin engined Spitfire was 286/296 IG, 266 IG for a Griffon engined one. The maximum external fuel load was 90 IG, about 28 IG was needed for take off. So if there's no wing tanks then your maximum fuel load in this scenario is 85/96 IG front fuselage and 28 IG rear plus 90 IG slipper. So max combat radius should be about 270 miles. If you added wing tanks of 28 IG and another rear fuselage tank of 28 IG then you should get a combat radius of about 360 miles.
The base line Spitfire had a combat radius of 100 miles, add a 60 IG P-40 drop tank under the fuselage and you should get about 180 miles.
You're not going to get to Berlin and back in a Spitfire fighter.

 

[Peter Gunn]

I don't know why you guys are having such a hard time figuring range, on my way back from Michigan last week I just hit the "Range" button on the touch screen in my XT4 and it gave me the number of miles/km I could go at my current speed with what was in the fuel tank.

I mean, c'mon guys, it ain't rocket science...

 

[pbehn]

I don't know why you guys are having such a hard time figuring range, on my way back from Michigan last week I just hit the "Range" button on the touch screen in my XT4 and it gave me the number of miles/km I could go at my current speed with what was in the fuel tank.

I mean, c'mon guys, it ain't rocket science...

Thats OK as long as no pesky bandits make you put your foot down.

 

[Shortround6]

I don't know why you guys are having such a hard time figuring range, on my way back from Michigan last week I just hit the "Range" button on the touch screen in my XT4 and it gave me the number of miles/km I could go at my current speed with what was in the fuel tank.

I mean, c'mon guys, it ain't rocket science...

Yep, it is much more complicated than that

How many turns on what size rubber band will give how many seconds into the head wind we have today?

Or what is the airspeed of an unladen swallow?

 

[soulezoo]

Is that an African or European swallow? (and where's the coconut?)

 

[BiffF15]

And what's your favorite color?

 

[Peter Gunn]

And what's your favorite color?

GREEN! NO... PURPLE... WAIT!!! Bwaaaaaaaaaaaaaaaaaaaaaaa...

 

[Zipper730]

AFAIK the maximum fuel load of a Merlin engined Spitfire was 286/296 IG, 266 IG for a Griffon engined one.

The Griffon engined variants had LESS internal fuel?

S Shortround6 W wuzak do you have any figures for the rear tanks used on the Spitfire and the tank used on early PR variants under the pilot's chair?

 

[pbehn]

The Griffon engined variants had LESS internal fuel?

S Shortround6 W wuzak do you have any figures for the rear tanks used on the Spitfire and the tank used on early PR variants under the pilot's chair?

Its easy enough to find on the net. The Griffon took up more space and needed a bigger oil tank.

 

[PAT303]

So max combat radius should be about 270 miles.

610 Squadron flew a fighter sweet from Tangmere to Isselburg, almost 400 miles with 90G D/T's and landed with 50-60G of fuel still on board. http://www.wwiiaircraftperformance.org/610-ORB-1sept44.jpg

 

[BiffF15]

610 Squadron flew a fighter sweet from Tangmere to Isselburg, almost 400 miles with 90G D/T's and landed with 50-60G of fuel still on board. http://www.wwiiaircraftperformance.org/610-ORB-1sept44.jpg

Any combat action on that sweep?

 

[Kevin J]

610 Squadron flew a fighter sweet from Tangmere to Isselburg, almost 400 miles with 90G D/T's and landed with 50-60G of fuel still on board. http://www.wwiiaircraftperformance.org/610-ORB-1sept44.jpg

Yes, an interesting route. I've just looked it up, you go via the Channel Tunnel. Now me, I'd have flown by air from Rochford airport just outside Southend on Sea to Isselburg.

 

[PAT303]

Any combat action on that sweep?

No, likely explains returning with so much fuel remaining.

 

[Kevin J]

No, likely explains returning with so much fuel remaining.

The longest flights were England to La Pallice, France and Darwin, Australia to Timor, Indonesia, both over water so you can do them using econ cruise.

 

[IdahoRenegade]

Combat radius depends/depended on many factors - how much of the time the engine was pushed to the max power, ratio between internal and 'droppable' fuel, altitude and speed of cruise and/or combat. So unless those things are specified, we will not be able to arrive at a strict figure.

What criteria did the AAC use for establishing the combat radius of escort fighters? Time to form up, fuel efficient cruise to enemy territory, high speed (defensive) cruise, XX minutes of combat, return, reserve? Had to be some standard to establish the radii defined for the P-47, P-38 and P-51. What would the various Spitfire configurations do under the same criteria?

 

[tomo pauk]

What criteria did the AAC use for establishing the combat radius of escort fighters?

Warm up + take off (all equivalent of 5 min normal power), climb to 25000 ft using normal power (the distance covered is NOT included in range/radius), cruise at 210 indicated air speed, 5 min combat at WER, 15 min combat at military power, return to base at 25000 ft and 210 mph IAS, 30 minutes allowance at min power. No allowances for evasive maneuvers apart that 20 min worth of combat. No 'bonus' accounted for the lightened aircraft returning to base.
As for how Spitfire will do under these conditions - you could take a look at aircraft's manuals (some can be found on this forum) and data sheets (like one here) and do the back-of-the-envelope math.