In the BoB having 30G behind the seat would have Spitfires at 25,000ft before the Luftwaffe bombers crossed the coast instead of climbing like hell from underneath them., likewise that extra fuel could increase their loiter time or allow greater tactical flexibility, there's no negatives for having extra fuel capacity.
British escort fighter--what might it have been like?
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drgondog
Major
Actually the Mustang drained as little of the 85 gal aux tank as feasible, and only used left main on takeoff. The drop tank was primary fuel source until empty or punched.
Shortround6
Major General
I believe, but could be wrong, that the Left main acted as the overflow tank for the carb/injector and took in 1-2 gallons an hour of flight time?
Let me rephrase, every long range aircraft development results in a loss of performance when the airplane is heavy. In reviewing aircraft tests available on the WW2 Aircraft Performance Site we can see the loss of climb rate on aircraft when carrying heavier full loads. The impact on a Spitfire MKV with 90 gallon belly tank is in the 500 ft/min range. There are also testing reports on aircraft with added fuel weight in the wings. Perhaps the best example is the P-47N. All of these document the loss of roll rate and affect on performance. As this thread has developed, I have been scouring for flight tests of the PR series Spitfires. While I haven't come across anything like a RAF Tactical Evaluation, I did find several references to the earlier PR Spitfires having balance issues and all PR Spitfires being less maneuverable.
We can't assume that the enemy will kindly wait around until we've burned off all our fuel to be at optimal fighting trim. On the outbound leg, the bomber force is more likely to be attacked as soon as possible to blunt the incoming attack, forcing the escort fighters to drop external tanks and fight with a max internal fuel load.
drgondog
Major
Yes. Beginning with XP-51F, the right Main became overflow destination, and introduced crossfeed from 105gal Right to the 75 gal Left. Ditto G/J and H (but H had 100gal Left Main).
I don't think anyone here is disputing this.
But, to reiterate what I wrote earlier, just because you have the possibility to load a lot of fuel into the aircraft, doesn't mean you have to do it for missions that don't require a full fuel load.
No fighter, including the fabled Mustang, had the endurance to be in combat from the French coast to Berlin and back. And I suspect no pilot had it either. What AFAIU they did for these long range bombing missions was that squadrons relieved each other. And obviously those squadrons responsible for the first leg (and last leg on the way back) didn't need to be loaded with as much fuel as those responsible for cover over the bombing target.
drgondog
Major
No, actually all escorts were fully loaded. The Penetration/Withdrawal assignments were largely P-47 and needed full internal fuel to reach intermediate R/V points for the 'relay' and hand off to the longer range escorts.
I've posted this before, but it helps illustrate how bomber missions were conducted. I believe drgondog previously identified this particular mission.
That's logical, when you have aircraft with different maximum range you can't use the short range ones for the long range missions (well, unless you're Greg and the plane is the P-47, but I digress).
You load the fuel you need (plus some reserve, of course). Or for an example, if the 8th had been equipped with P-51B/D from day one, the squadrons responsible for the first and last leg escorting would not be loaded with as much fuel as those responsible for the escort over the target.
Deleted member 68059
Staff Sergeant
- 1,058
- Dec 28, 2015
This is a useful image, I`m not finger pointing I would just like to post it somewhere else. Is this copyrighted ?
No
utopiayouarestandinginit.com
No worries, sir. I've never claimed it as mine. It looks like the original website is no longer active, but I did find a copy of what I believe is the original post.
Air Supremacy Battles – B-17G Flying Fortress and P-51 Mustang
Reblogged on WordPress.com
utopiayouarestandinginit.com
drgondog
Major
Howard's Medal of Honor mission.
Two things I take from that.
1.The distance to the target flown by both bombers and fighters is much longer than the straight line distance to the target.
2. If you cant confront a raid with equal numbers of fighters at the coast and conduct similar raids yourself the position is hopeless. Hamburg and Bremen are to the north of that raid, the Ruhrgebiet to the south. Other targets in the south of Germany could be approached via France. The LW needed many more A/C than the USA had to defend Germany or the territory it held.
drgondog
Major
I have reviewed 1000's of mission orders for different groups in 8th AF. The only variation to full load out referenced the amount of fuel in fuselage tank. Additionally, the normal SOP for P-51B/D equipped FGs was to load mains after every mission (unless written up on Form 1) prior to the next day. As I examined differences the most common was to also fill 110 gal (steel) externals at the same time and put 65 gal in fuselage tank.
The reason - as risky as it sounds to have fully loaded a/c ready to go the evening before, was the frag orders often did not come with enough lead time for the available number of fuel trucks to load every Mustang on the base in early morning- when the ops officers still has to make the selection re: who flys, along with engineering officer re: which 48-50 specific tail numbers would go.
After end of every mission the engineering officer pulled the recent returnees that had a Form 1 written up, placed it into 'fix' pool and selected from ships that did not fly that day but good to go. That usually meant that the ones that returned with no write up were refueled imediately,then engineering officer selected the several fill in's that were idle that day - ordered them refueled and informed each squadron ops officer of the assigned and ready to go squadron codes the afternoon/night before.
Things that complicated life for all were paper drop tanks which had to be installed new but on day of mission because they leaked. But if enough 110s were available they were usually selected and filled night before, along with 65 gal for fuse tank. Other complications really occurred with surprise Frag order issuing CAS mission with bombs - frequent after D-Day. During that period empty tanks would be removed - and either bombs or fuel tanks were installed (and filled, often in dark) and filled on morning of mission.
SOP was to retain steel tanks after drained for re-use if not dropped for combat. Always dropped paper tanks.
There are gaps in my sagging memory but I think the above is about right.
drgondog
Major
True, But
The Germans were clever fellows with early warning beginning at start engine time, eyeballs and binocs on both coasts, radar and reasonable central control digesting the data to develop informed opinions about the target intentions. They had constant contact with the fighter units in range of the actual course line and usually had spies in the form of Ju 88s stalking the bomber formations and radio contact to inform control of course and altitude.
The prize was to a.) detect task forces separated from others, b.) detect lack of escort either due to being off course/time for R/V, and c.) Fighter commanders who judged fight or run based on escort strength - or played in cloud cover seeking an opening.
The LW got increasingly better at finding weakly escorted 'holes' in a 30-50 mi bomber stream, and directing an unmolested Gruppes to that region in space
This report clearly states that the reserve tank be used first for warm up taxi take off and climb with no combat or hard maneuvering with the rear tank more that half full.
Pretty much what has been said numerous times, about 10 times so far on this thread alone on how it could and was ultimately done, unfortunately too many people have fixated on the Portal mentality of it's impossible to achieve.
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Shortround6
Major General
I would guess that time, other equipment and exact model of the P-51 changed the things around a bit.
By 1951 P-51Ds were NEVER supposed to put more than 65 gallons in the rear tank.
However, They were supposed to to ALWAYS keep 25 gallons in the rear tank even for landing.
So with that ever tanks the P-51Ds were using and whatever radios and other gear (and whatever little fins they may have) the difference between to much fuel for adt center of gravity and too little fuel was about 40 gallons (lite gallons).
If you ran the main tanks dry you could use the 25 gallons in rear tank as reserve but you were supposed to have planned the flight to land with the 25 gallons untouched and with at least few gallons in the main/s.
I am not saying that this was ever WW II practice. I am saying that seems to have been some shifting around as to what was OK and what was not. And it may have changed between the high back and bubble tops or not?
Also the test report clearly states that the test tank had no baffles and production tanks should have baffles to prevent fuel movement both longitudinally and laterally. Which may very well affect the limits needed.
All Spitfire tanks were two piece, an upper and lower for precisely this reason, our escort Spitfire would have use the very same tactics escort Mustangs did use, from fuel management to relaying flights.
drgondog
Major
The operational requirements dictated the instructions regarding the tankage - Everyone Knew the issues surrounding accelerated turns. The answer, "if you find yourself in a hard mauevering fight with full load, Go with God - but avoid that if possible'.
Figter pilots duly noted 'reports' and Tech Orders but they served, like regulations, only as a guide.
