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Resp:At the start of the war, the Japanese used unprotected fuel tanks and were noted for burning easily, not a configuration one would like to fight with.
In early '43, the F4U would be the -1 version without water injection and the P-51 would be the baseline version with the -39 engine. The P-51A with the -81 engine, which was coming out at this time was a great performer even in the ETO where it was equal to or was out performing most Allied and Axis fighters up to 15K, maybe a bit higher. The data I have, mostly from Spitfireperformance shows the P-51A outperforming the F4U-1, often significantly, in both airspeed and climb up to about 23k ft, where the F4U-1 catches up. Unfortunately, the P-51A performance at these altitudes, was NOT deemed acceptable for combating the latest German fighters as power was dropping off quickly, AND, since the the F4U-1 had less than or similar performance of the P-51A, and, power was also dropping off quickly at altitude, neither would be acceptable as a high altitude bomber escort. Why would the AAF select a completely different aircraft when a better performing P-51A was coming off the assembly line, and the clearly superior P-51B was being built and was in flight test. In August, 1943, the water injected F4U-1(A) became operational and was a significant improvement over the F4U-1, mission operations began later in October. However, on December 1, 1943, about a month later, the P-51B flew its first sweep over France. It is apparent that the F4U would not have provided an acceptable bomber escort before the P-51B Mustang became available.
In 1942 and early 1943 8th AF planners directed the Bomb Wings to bomb from 9,000 to 17,000 on several missions (but not Most) to sub pens - but consistent doctrine throughout the ETO war was 22-27K. Later in 1944, B-24s were all combined into 2nd BD and they bombed primarily from 21-22K as the formation flying with B-24s was increasingly tricky above 24K.Resp:
When I reviewed individual AAR by 8th AF pilots for the year 1943, I was surprised that most bomber formations were @ 12,000 to 14,000 ft. Also noted that weather (pilot mentioned cloud ceiling) brought flying altitudes much lower than what was preached. If I remember correctly, P-47s flew 2 to 3 thou ft above the bombers. However, this all depended on 'ceiling' visibility.
Below 20,000 feet? F4U-1A moderately superior maneuverability but slower.
Resp:P-47C, G and early D have had a belly tank that was able to hold 200 gals, workable between SL and ~15000 ft due not being pressurized (fuel will be boiling above that altitude). People at England were filling it half full, sent them towards German-held Europe, combat radius was ~350 miles. People in Australia were faster on the ball, and produced metalic tanks in Brisbane, that IIRC were able to be pressurized, and held 200 gals. Flat-ish shaped.
Americans were flying a quantitiy of P-47s via Iceland, using two wing drop tanks, August 1943. Per 'America's hundred thousand'.
F4U should not have problems flying well above 30000 ft.
Vought data states combat radius of the F4U at, IIRC, 325 miles with 1 drop tank, and 350 miles with two; stated is that internal fuel is the limiting factor.
"Dawncaster, post: 1413363,
I agree most of your points, but your data for the P-47D-10 data you showed was for std 130/100 octane and 56" at WEP. To look at P-47D operational data with 44-1 fuel in mid 1944 and 65/70" MP shows the speed advantage at 439mph at 65"MP with WI (and 444 mph at 23K with 70" and WI. 417 mph at 14,000 and 70"MP. The performance for the R-2800-63 with WI and 44-1 fuel was in ops in mid 1944. A little after F4U-1A deployed to the Fleet/USMC in SWP.
http://www.wwiiaircraftperformance.org/p-47/p47d-44-1-level.jpg
That said, I was in error when I stated that the P-47C/D was faster than -1A, I meant F4U-1. To follow your thread, the next block of comparisons should be F4U-4 vs P-47M or even early delivery P-51H-1
Resp:I think the Corsair had a good 'range'.
View attachment 499305
However, there is a kind of range and it has different 'Combat Radius' depending on the mission profile. No matter how much fuel Corsair could have, if most of it's an extra fuel, It's not suitable for combat. In simple terms, the maximum combat radius refers to the situation in which the Corsair maintains 237 gallons of protected internal fuel as it enters the aerial combat and it's enough for combat and return. more extra fuel than that makes the Corsair to have a drop tank in air combat.
well, According to the 1945 Aircraft Action Reports, Corsairs take off for cap & fighter weep with two 150 gallon drop tanks or one 175 gallon drop tank and sometimes kept the drop tanks when they returned. However, it's fundamentally dangerous and the drop tank had been stated to cause buffeting in action report.
Another problem was the altitude performance of the dash 1 Corsairs.
View attachment 499310
Curve 5 shows the range at 1.5k, 15k and 25k under the same conditions. (3 for internal 237 gal only, 4 for 1 drop tank, 5 for 1 drop tank + 1 permanent tank)
As you can see, the range was decreasing as the cruise altitude increases.
at 1,500ft = 1895 miles with 176 mph - 100%
at 15,000ft = approx 1850 miles with 205 mph - 97.6%
at 25,000ft = approx 1750 miles with 250 mph - 92.3%
but case of ETO USAAF trio,
View attachment 499313
P-51s
View attachment 499315
P-38s
View attachment 499316
P-47s
Their range was increasing as the cruise altitude increases.
If internal fuel only, Corsair's range seems to be longer than the early USAAF trio, because it's calculated with best* cruise altitude. However, at altitude required by ETO USAAF, it was actually similar or shorter than trio. at 25,000 ft, perhaps it still would be slightly longer than the early P-38/47 without later version's additonal internal fuel tanks, but It's clearly shorter than the early P-51B/C.
* especially at 6,500ft that stated in pilot's hand book for dash 1 corsairs. it showed 1150 miles with 237gal intenal fuel - approx 15% longer than ACP's range at 1,500 feet.
As the early P-38/47 did, it seems clear that the Corsairs was also unable to fully escort the heavy bombers. And according to the requirements on the war, they and the Corsair were upgraded in different directions. Therefore, there is no need to consider the cruising speed required for deep and high escort. it's inappropriate.
Anyway, the dash 1 Corsair was not a particularly low altitude fighter, It's critical altitude was similar to Fw 190 A/D or Typhoon/Tempest. compared to them, enough performance, good maneuverability, high payload, and longer range would be good to use as medium altitude fighter or fighter-bomber, as in PTO.
Of course, there was no need for a 'new' fighter of such type for the USAAF in ETO.
However, Once the Corsairs of the Marine Corps was considered for special mission. It's the following incident.
'One of the most intriguing aspects of US Marine Corps aviation in World War II involved events far, far removed from the Pacific. In mid June 1944 German bases in northern France began launching V1 "buzz bombs" against London and environs. The early cruise missiles were wildly inaccurate but caused widespread damage.
Project Danny was the US Navy/US Marine Corps portion of the broader Allied effort called Operation Crossbow – air attacks on V1 sites. Because the launch batteries were so small, they were both hard to find and to strike by conventional bombers. One of the options seriously considered was placing US Marine Corps F4U squadrons on escort carriers in European waters, arming the aircraft with 12.75in. Tiny Tim rockets and using them against the "doodlebug" sites. The US Navy was serious enough to assign a full Marine air group to Danny – five Corsair squadrons of Col Edward Pugh's MAG-51. Training proceeded on both coasts, with carrier qualifications (CQs) and specialized weapons qualification. However, low Tiny Tim production hampered pilot familiarization with the weapon.
The program soon ran afoul of more serious problems on the home front too – the "battle lines" along the Potomac River. The US Army chief of staff, Gen George C. Marshall, harbored a lingering resentment toward the US Marine Corps dating from the Battle of Belleau Wood in June 1918, when two "devil dog" regiments grabbed most of the headlines despite them serving in a US Army division. Vice Adm Patrick Bellinger, Commander Naval Air Forces Atlantic Fleet, arranged for a Joint Chiefs briefing on Danny, with Cdr Thomas Moorer conducting the presentation. Marshall listened to part of the briefing, then stood up. On the way out he said, "There will never be a Marine in Europe as long as I'm chief of staff."
Moorer, a future Joint Chiefs chairman, realized that the program was almost certainly doomed. He was right – Danny was canceled at the end of July. In addition to political infighting in Washington, D.C., it is uncertain how far the project would have proceeded. Danny was overtaken by events on the Continent, as Anglo-American armies had liberated most of northern France by the end of September. The squadrons resumed ordinary predeployment training for the Pacific instead.'
View attachment 499391
Booooo~~~
Below 20,000 feet, P-47C/D was slower than F4U-1A.
If it's P-47B vs early birdcage F4U-1, I would have agreed. According to the test flight documents, P-47B was faster than P-47C/D. Perhaps it seems to be due to lighter gross weight and shorter fuselage, different propeller blades. On the other hand, the early Birdcage F4U-1 had less altitude performance than the F4U-1A. with same power - military rating, it's only 2 mph slow at sea level, but 12 mph at 10,000 feet and 13 mph at 20,000 ft. so F4U's speed advantage was only for neutral blower.
but P-47D vs F4U-1A, it's different case.
due to improved altitude performance, F4U-1A was faster than P-47D up to it's critical altitude - 20,000ft. and even without water injection, the F4U-1A was almost as fast as the P-47D with water injection. and 2600 bhp, overboosted 65"hg P-47D also slower than F4U-1A with water injection at below 20,000 ft.
View attachment 499381
Considering the difference in sea level speed between early Birdcage F4U-1 and F4U-1A, the difference in drag was not large(without SC - in pure output but only 2 mph Vmax difference). Idk exact reason, but the supercharger of the F4U-1A was much better perform than the early Birdcage F4U-1. Therefore, F4U-1A was able to bring its speed advantage up to 20k against P-47D. and the new 6501A-0 propeller blade also helped raise altitude performance.
Resp:P-47C and early Ds of the 4th, 56th and 78th FG were using the flush-fitting 200 gallon tank operationally from mid-summer '43 onward. The only problem was that the tank needed to be pressurized above 10,000, so they only carried 100 gallons.
However, by August of '43, they had devised a way to pressurize the tanks which also allowed them to use other tanks, including the British made paper tank.
The F4U-1A still had the two 62 gallon wing tanks. From the 863rd aircraft, the P&W R-2800-8W had a water injected engine, giving it 2250 HP. Would the water injection help at altitude?
Resp:Short answer is no.
The long answer is it depends on the engine's critical altitude and what you would consider to "at altitude".
Water injection or Anti Detonation Injection (ADI) allows more boost without causing detonation. More boost gives more power, but a lower critical altitude.
What will happen, therefore, is the higher boost level with ADI will be held to the critical altitude for that boost level. Above the critical altitude the boost will fall off until it reaches the non-ADI maximum boost level and the critical altitude for that boost level. Between the two critical altitudes the boost will be above the non-ADI boost, so ADI is required.
It seems to be 1-2,000ft difference between normal and military power critical altitudes for the F4U-1, and 4-5,000ft difference from normal to combat power.
Combat power critical altitude ~18,000ft.
Resp:P-47C and early Ds of the 4th, 56th and 78th FG were using the flush-fitting 200 gallon tank operationally from mid-summer '43 onward. The only problem was that the tank needed to be pressurized above 10,000, so they only carried 100 gallons.
However, by August of '43, they had devised a way to pressurize the tanks which also allowed them to use other tanks, including the British made paper tank.
Resp:
Would a higher actane fuel improve performance in an F4u-1A?
It seems to me that in 1939/40 no air forces had drop tanks, so was there a problem with the fuel transfer technology that prevented their use?
Resp:
When the commander of 5th AF Gen Kenney was told that he would no longer be getting P-38s, but instead P-47D-5 and -6, and that they were not drop tank capable . . . he reluctantly accepted. He immediately called his engineers and told them to construct a drop tank. The he took the diagram/figures to Ford Motor Co of Australia to have them produce a 200 gal drop tank. In just less than 60 days, his P-47s were flying long range mission. What did 8th AF, complained and waited.
I question the date of P-47s with two wing drop tanks. A ferry tank of 200 gallons? Yes in August 1943.
Internal fuel for F4U is the crucial issue to ETO long range escort.
Germans used drop tanks on their fighter biplanes in 1930s, US used external taks (both 'slipper' and drop-shaped) on their fighter biplanes in 1930s. Plus the Japanese on A5M Claude, at least.
The 8th AF did not waited, though they probably compained, and rightly so, since the value of escort fighter was known well before ww2 started, and at least the Battle of Britain proved that once again, on large scale. Had the brass at USAAF listened, the P-47 would've been outfitted with suitable drop-tank capability from day one, with easy 450-500 mile radius of action.
People at 8th were 1st filling the 200 gal ferry tank half full, then used 75 gal DT, then the 108/110 one. Just like they replaced the US-produced radio with British set so pilots can communicate, just like they were modifying engines to work reliably - all in Spring/Summer of 1943.
The entry for the P-47, pg.288, in the 'America's hundred thousand' book, states that in August 1943, ten P-47D-5 were outfitted with 2x165 gal drop tanks, and were air-ferried to the UK.
This is taken from the manual for the P-47B, C, G, and early D, dated January 20th 1943. Manual plainly states that P-47B is not outfitted with drop tank facility, while later models (C, G, D) have it.
View attachment 499514
Resp:Germans used drop tanks on their fighter biplanes in 1930s, US used external taks (both 'slipper' and drop-shaped) on their fighter biplanes in 1930s. Plus the Japanese on A5M Claude, at least.
The 8th AF did not waited, though they probably compained, and rightly so, since the value of escort fighter was known well before ww2 started, and at least the Battle of Britain proved that once again, on large scale. Had the brass at USAAF listened, the P-47 would've been outfitted with suitable drop-tank capability from day one, with easy 450-500 mile radius of action.
People at 8th were 1st filling the 200 gal ferry tank half full, then used 75 gal DT, then the 108/110 one. Just like they replaced the US-produced radio with British set so pilots can communicate, just like they were modifying engines to work reliably - all in Spring/Summer of 1943.
The entry for the P-47, pg.288, in the 'America's hundred thousand' book, states that in August 1943, ten P-47D-5 were outfitted with 2x165 gal drop tanks, and were air-ferried to the UK.
This is taken from the manual for the P-47B, C, G, and early D, dated January 20th 1943. Manual plainly states that P-47B is not outfitted with drop tank facility, while later models (C, G, D) have it.
View attachment 499514
These P-47 groups had devised a way to pressurize their tanks using air pressure from the airpump that typically bled off into the exhaust, a certain type of thermostat that was scrounged locally and a glass elbow tube all before August '43....Note that most of the P-47s in England had to have kits installed in order to carry one belly tank. The three fighter groups rotated through 'retro fit' centers using kits sent from the US. This was done/completed @ Sept 1943.
Resp:
Recommend you read the history of the
Resp:
P-47 Drop Tanks in ETO:
- July/Aug 1943: used 200 gal ferry tanks (particularly filled). Not a drop tank but could be released in flight, but more often than not, it failed to jettison.
- 31 Aug 1943: 75 gallon tear drop shape, initially designed for P-39. In 1944, used as underwing tank.
- Sept 1943: 108 gal British designed/ manufactured paper tank. Used as wing tanks Apr 1944
- Feb 1944: 150 gal drop tank. Used as under wing tank 22 May 1944
- Feb 1945: 215 gal belly tank
Note that most of the P-47s in England had to have kits installed in order to carry one belly tank. The three fighter groups rotated through 'retro fit' centers using kits sent from the US. This was done/completed @ Sept 1943.
I have a photo of a P-47D-1 at Meeks Field, Iceland with cowl flaps and two 150 gal tanks fitted, one under each wing. However, initially, the wing hard points were for bombs only. The first production P-47 that had 'wet' wing hard points was the P-47D-15. The photo states that the tanks are Lockheed underwing fuel tanks. I suspect these were 'tubed' for the ferry flight to England. It looks like Apr/May 1944 before P-47D-15 became operational in the ETO.
PS. Able to carry a ferry tank is not the same as drop tanks, as ferry tanks work at lower altitudes and in level flight. Drop tanks are designed to be released from the aircraft when empty or just prior to combat. They must also work at all altitudes.
Resp:These P-47 groups had devised a way to pressurize their tanks using air pressure from the airpump that typically bled off into the exhaust, a certain type of thermostat that was scrounged locally and a glass elbow tube all before August '43.
That is a little too simplistic.Resp:
Agreed. That they perfected it . . . before August 1943, I can agree to. LOL! Somewhere my mind says Sept 43 was when they completed retro fit of their P-47 in Theater.
I have a book that covers 8th AF. Gen Arnold was very disappointed wth Eaker. Both bomber and fighter commanders were relieved, 30 days w/in one another. Eaker did not understand the importance of escort fighters for bombing. His air mission planner, a LTC, came to Eaker to ask his advice . . . was told to do whatever he thought best. He never offered any assistance in regard to mission priorities. When Eaker gave the first Mustangs (P-51Bs) to arrive in the ETO away to the 9th AF, Arnold was furious! To get use of the Mustangs for escort, 9th AF was tasked with providing escort for 8th AF. Doolittle soon relieved Eaker. When Eaker asked the planning officer to accompany him to the Med, the officer declined.