Escort Fighter Performance Comparison

[WARSPITER]

View attachment 682428

It's also helpful to ensure one's moron magnet is turned off at appropriate times.

 

[NevadaK]

It wasn't aimed specifically at you, NevadaK. Just to add information to the thread and repeat it because it hadn't sunk in...

No worries, Nuuumannn! My tongue was firmly in my cheek when I wrote that.

 

[Geoffrey Sinclair]

For when this starts up again, from "Case History of Fighter Plane Range Extension Program, Parts I and II," USAF Historical Research Document 202.2-11, 22 February 1945, Enclosure 1.

a Fuel Consumed in Gallons for 5 minutes War Emergency Power & 15 minutes Military Power.
b Fuel Consumed in Gallons during Warm-up, Take-off, and Climb.
c Horizontal Distance to Climb to 25,000 feet.

P-38H Internal Tanks Only. 15,900 pounds take off weight, 300 gallons total fuel, 111 (a), 86 (b), 40 miles (c), range 326 miles
P-38H plus 2x150-Gal External Tanks, 18,000 pounds take off weight, 600 gallons total fuel, 111 (a), 98 (b), 50 miles (c), range 1,005 miles

P-47D Internal Tanks Only. 13,500 pounds take off weight, 305 gallons total fuel, 89 (a), 101 (b), 57 miles (c), range 473 miles
P-47D plus 2x150-Gal External Tanks, 15,600 pounds take off weight, 605 gallons total fuel, 89 (a), 125 (b), 81 miles (c), range 1,045 miles

P-51B Internal Tanks Only. 9,050 pounds take off weight, 180 gallons total fuel, 58 (a), 46 (b), 50 miles (c), range 415 miles
P-51B plus 2x150-Gal External Tanks, 11,150 pounds take off weight, 480 gallons total fuel, 58 (a), 59 (b), 80 miles (c), range 1,570 miles

 

[drgondog]

For when this starts up again, from "Case History of Fighter Plane Range Extension Program, Parts I and II," USAF Historical Research Document 202.2-11, 22 February 1945, Enclosure 1.

a Fuel Consumed in Gallons for 5 minutes War Emergency Power & 15 minutes Military Power.
b Fuel Consumed in Gallons during Warm-up, Take-off, and Climb.
c Horizontal Distance to Climb to 25,000 feet.

P-38H Internal Tanks Only. 15,900 pounds take off weight, 300 gallons total fuel, 111 (a), 86 (b), 40 miles (c), range 326 miles
P-38H plus 2x150-Gal External Tanks, 18,000 pounds take off weight, 600 gallons total fuel, 111 (a), 98 (b), 50 miles (c), range 1,005 miles

P-47D Internal Tanks Only. 13,500 pounds take off weight, 305 gallons total fuel, 89 (a), 101 (b), 57 miles (c), range 473 miles
P-47D plus 2x150-Gal External Tanks, 15,600 pounds take off weight, 605 gallons total fuel, 89 (a), 125 (b), 81 miles (c), range 1,045 miles

P-51B Internal Tanks Only. 9,050 pounds take off weight, 180 gallons total fuel, 58 (a), 46 (b), 50 miles (c), range 415 miles
P-51B plus 2x150-Gal External Tanks, 11,150 pounds take off weight, 480 gallons total fuel, 58 (a), 59 (b), 80 miles (c), range 1,570 miles

The P-51B never used 150 gal tanks, only 75 and 110 in ETO/MTO. Only later in Pacific for VLR missions was the larger tank used on P-51D and only enabled ~25 to 50 miles more combat radius.

Comments regarding the sources:
The 'range figures' are all over the place with respect to 'Range-ferry', Range - Combat Radius (planning calculations dependent on multitude of take off, assemble, climb, cruise, fight, cruise home loiter. The nature of the escort also crucial to planning - ranging from Sweep greater than 'normal' escort in which the fighter maintained contact with escorted bombers from distant RV from Target, and finally Target Escort in which the escorts flew to R/V reasonable close to the target - in which close escort was 30 to 45 minutes.

The Fuel consumed is accurate for MP and WEP for 130 octane fuel.

For 25,000 feet, Optimal cruise settings for maximum range did not quite achieve the same values as lower altitudes. The reduced drag at 25,000 vs 10,000 feet cruise was offset by the extra fuel consumed to climb the extra 15,000 feet

The P-38H values you referenced are not useful from Q4/43 to Jan/44. The Operating value for H Ferry Range w/300 gal was ~ 850mi. The Combat Radius for the J-5 and early J-10 are similar but the LE 55 gal tanks were installed as kits in the J-10 and early J-15 to significantly extend combat radius. With 2x150gal externals the CR for planning purposes for P-38H/early J was ~ 440mi not 1005 mi. The Ferry Range was ~ 850 mi with 300gal internal only,

The P47D at block level below P-47D-25 (operational in late Q2/44 in small quantities - fuly operational in Q3) was far lower than stated. With internal fuel, no external tanks, the CR was approximately 125mi and Ferry range 830mi.

Had the P-47C-2 through P-47-23 had only 305gal internally but able to have CR of 473mi, the 8th AF could have escorted all the disastrous 1943 and spring 1944 missions to the target, save Berlin and Munich. Would not have required P-38J with 55gal LE tank or P51B with internal 85 gal tank to rush to ETO in Fall 1943.

Only the P-47N with 556gal internal and 440 gal exteral and the P-51D with 269gal internal and 330gal externally had CR of 1000mi and Ferry rangse of 2300+mi. That said the P-38L could achieve the same Ferry range operating at low speed/low altitude

The P-51B with 180gal wing fuel, no 85 gal fuse tank, and no external tanks had a Ferry Range of about 1,200 miles but a Combat Radius of only150mi. Have zero idea where the author of the study was researching but it wasn't in ETO or NAA Pilot's handbook or Wright Field testing.

This extraction is completely bogus "P-51B plus 2x150-Gal External Tanks, 11,150 pounds take off weight, 480 gallons total fuel, 58 (a), 59 (b), 80 miles (c), range 1,570 miles.

A P-51B with only internal 180gal plus the aforementioned bogus 2x150 gal externals is cited for 480gal of fuel. That GW would be 9,050 + (300)x6 = 9,050 +1800 = 10, 850 pounds Take off - not 11,150. This config was never used in combat without 85 gal fuselage tank. Doubt that it was tested when the 150gal combat tank was released just before the P-51B w/85 gal internal fuse tank was in production.

A P-51B w/85 gal fuse tank plus 2x110gal externals is 9,132 (NAA) base fuly loaded internally for 180gal wing tank plus ammo plus oil plus pilot @200, Add 85gal (fuse tank) plus 220gal (2x110gal) = 9,132 + 85x6 + 220x6 = 10,962 (per NAA) GW at Take off. The delta for filling wing tanks from 180 to 184gal is 24 more pounds, which is more common load out for P-51B.

The P-51B with 2x75 gal externals and 184gal + 0 gal Internal ~ had a CR of 470mi, and Ferry range of 1575mi.
The P-51B with 2x75 gal externals and 184gal + 85gal Internal ~ had a CR of 705mi, and Ferry range of 1,800mi.

It was meaningless for this study not to use Manufacturer Handbooks for foundation references.


Last but not least, any attempt to cite range without specifying cruise settings and altitudes is simply demonstrating ignorance of aircraft performance boundary conditions for conversation context.

 

[33k in the air]

A P-51B with only internal 180gal plus the aforementioned bogus 2x150 gal externals is cited for 480gal of fuel. That GW would be 9,050 + (300)x6 = 9,050 +1800 = 10, 850 pounds Take off - not 11,150. This config was never used in combat without 85 gal fuselage tank.

The weight of two 150-gallon drop tanks would add at least another 158 to 240 lbs, depending on the empty weight of the drop tank (the figures vary). So that would bring the total weight up to 11,008 to 11,090 lbs.

 

[Geoffrey Sinclair]

The Fuel consumed is accurate for MP and WEP for 130 octane fuel.

People have been after the breakdown of the consumption figures for quite a while, why wait to issue a confirmation after someone else provides them?

Had the P-47C-2 through P-47-23 had only 305gal internally but able to have CR of 473mi,

The figure supplied were 473 miles range, not radius.

A P-51B with only internal 180gal plus the aforementioned bogus 2x150 gal externals is cited for 480gal of fuel. That GW would be 9,050 + (300)x6 = 9,050 +1800 = 10, 850 pounds Take off - not 11,150. This config was never used in combat without 85 gal fuselage tank. Doubt that it was tested when the 150gal combat tank was released just before the P-51B w/85 gal internal fuse tank was in production.

Actually it seems there was a 1943 trial of 150 gallon external tanks on a P-51B, a 28 October 1943 memo to General Myer reports on planned trials P-38J, P-47D and P-51B each with a pair of 150 gallon external tanks, the P-38J and P-51B due at Elgin field on 1 November, the P-47D awaiting good weather and will go to Elgin via Wright.

Now this has started up again, it meant going and finding the study, not just a document that quoted one of the tables, results below. Back to the study, from "Case History of Fighter Plane Range Extension Program, Parts I and II," USAF Historical Research Document 202.2-11, 22 February 1945, Inclosure 1.

Timeline

20 February 1942, memo requesting ferry range extension for P-38, P-39, P-40, P-47, P-51 and P-61

25 February 1942, conference in General Arnold's office about range extension of pursuit, dive bomber and light bombers.

13 March 1942, P-47B 220 gallon belly tank, 100 gallon tank under each wing, gross weight 17,516 pounds including guns and ammunition, take off over 50 foot obstacle estimated as 4,500 feet. P-38 2x175 gallon (inboard) and 2x75 gallon (outboard), gross weight 20,000 pounds including guns and ammunition, take off over 50 foot obstacle estimated as 3,500 feet.

21 March 1942 conference at Wright Field, initial efforts to increase pursuit types range. Priority to ferry operations, range without removal of equipment, non droppable non leak proof tanks, plus combat range extension with non droppable leak proof tanks for missions lasting 6 hours plus a 30 minute reserve allowance.

27 March 1942, state of play, 75 gallon tanks for F-4 being delivered, 150 gallon tanks wind tunnel tested, this size appears to be the limit drag wise, study on P-38 to increase range to 3,000 miles. P-47, Republic to install two 75 gallon droppable tanks installations and design and test belly tanks to increase range to 3,000 miles, to also proceed with 200 gallon leak prof belly tanks and study development of 600 gallon tank for ferrying.

31 October 1942, P-38 with 2x300 gallon tanks flown for 3,000 mph at 10,000 feet, average speed 213 mph. Medical examination of pilot shows normal fatigue after 13.5 hour flight, therefore project considered practicable. P-47 wind tunnel tests ruled out the 600 gallon tank, study made of Lockheed 300 gallon wing tanks. P-39 unsuccessful flight with 350 gallon belly tank, 2,400 miles range, poor directional stability, to make it acceptable an extra 20 gallons external added, removal of nose guns and other items to allow a 57 gallon nose tank, range to 2,800 miles. P-40 trial with 3x170 gallon external tanks had directional instability and too much drag, 2x170 gave 2,255 miles. 4,000x170 gallon tanks on order.

3 July 1943, flight tests, fuel consumption P-51B, 64 gallons per hour over 4 hours and 45 minutes, 184 gallons of internal and 150 gallons external, P-47D 140 gallons per hour over 3 hours, 305 gallons of internal and 165 gallons external, P-38J 144 gallons per hour, over 4 hours, 300 gallons internal, 300 external.

12 August 1943, P-51D to have wing moved further forward, allowing removal of 50 pounds of tail ballast but this will make carrying rear fuselage fuel more difficult.

21 August 1943, tests showed 85 gallon rear fuselage tank the largest that could be fitted to P-51 Test of 269 gallons internal plus 80 gallons in a pair of 75 gallon wing tanks, tanks dropped at 25,000 feet 200 miles from base, another 1,000 miles flown, 4 hours of flight, 35 gallons remained. The rear fuselage tank meant the SCR-274 and IFF could not be carried, the latter change unacceptable. Leading to ideas like the IFF set in the engine compartment.

25 August 1943, drawings for P-51 fuselage tank about ready, 3 hand built tanks expected to be ready mid September, no IFF or provision for IFF.

3 September 1943, General Arnold reports USAAF in Britain states long range fighters must be provided to accompany daylight bomber operations. Given this will increase fighter losses fighter production needs to be increased. The need to stay near the bombers if they are cruising at 160 mph IAS while the fighter is at 220 mph IAS means the P-51B with 180 gallons internal and 75 external has a combat radius as an escort of 250 to 350 miles, but as an offensive fighter 350 to 500 miles, the P-38J with 290 gallons internal and 300 external figures are 200 to 300 miles and 300 to 450 miles respectively. Adding 85 gallons of internal fuel makes the P-51 figures 550 to 700 miles and 700 to 850 miles, adding 120 gallons internal makes the P-38 figures 375 to 475 miles and 550 to 700 miles. Long range pursuit project now has AAA priority.

8 September 1943, P-51D configuration, 6 wing guns, 55 gallons rear fuselage tank. Long range B and C priority ahead of D or at least the 6 gun wings.

17 September 1943, adding an extra 65 gallons of internal fuel to the P-47 requires raising the cockpit floor and changing of all bulkheads and fittings in the front part of the fuselage, 2 months required for a prototype.

20 September, proposal for external 300 gallon self sealing all purpose ferry tank, able to take fuel, personnel or cargo, 2 prototype examples costing $110,000 and 23 prototypes of another design costing $17,825

1 October 1943, order for a pair of each prototype drop tanks of British type paper, 108 and 150 gallon priced at $350 each.

15 October 1943 P-47 were equipped with the B-10 shackle, pressure relief valve and plumbing to carry the 75, 100 and 150 gallon tanks, in addition wing attachments for 150 gallon tanks were provided. As the P-39 and P-40 had the B-7 shackle they could also use the tanks.

19 October 1943, Farmingdale P-47 production fitted with wing attachments for 150 gallon tanks.

23 October 1943, General Arnold personal letter to drop tank making companies, impressing how important their work is.

11 November 1943, P-51 long range modifications top priority except the P-39 delivery schedule to Russia must be maintained.

16 November modification centre installation of P-51 85 gallon rear fuselage tank, first installation to take 1,000 hours, then 600 per additional airframe.

17 November, defects in cowling production are hampering P-47 production. Sub contractor reports army took skilled welders plus engineering difficulties. Evansville not installing wing tank fittings as they do not have engineering data. Farmingdale reports wing tank fitting needed to be done by hand and were working loose during engine testing. Wing subcontractor expected to deliver wings with fittings already installed.

24 November 1943, P-51 modification above all other work except for the C-46 and aircraft for Russia.

29 November 1943, 220 P-51 and 156 P-38 have been in modification centres for over a month.

November 1943, conference about air to air refuelling of pursuit types by the bombers they were escorting.

4 December 1943, order for nesting type 150 gallon drop tanks for the P-38 at $812 each, designed to be built and shipped in halves to enable much more efficient shipping of the tanks. The USAAF requirements to transport large numbers of empty containers took lots of ship volume.

P-51, the 85 gallon rear fuselage tank reported to have added about 650 pounds when full, with the fuel weighing around 500 pounds.

Combat Radius, for fighters accompanying B-17 cruising at 185 mph IAS, fighter at 210 mph IAS (300 mph true), warm up 5 minutes rated power, maximum continuous power climb to 25,000 feet, drop tanks when empty or on radius, 15 minutes combat power, 5 minutes war emergency power, 30 minutes reserve at minimum cruise speed. Following read from a graph.

P-51B/C, 180 gallons internal, radius 175 miles, with 2x75 gallon external tanks radius 500 miles. 265 gallons internal, radius 400 miles, with 2x75 gallon external tanks radius 750 miles.

P-47D, 305 gallons internal radius 150 miles, 305 gallons internal +75 external 250 miles, 305 gallons internal +108 external 300 miles, 370 gallons internal radius 250 miles.

P-38J, 300 gallons internal 125 miles, 420 gallons internal 275 miles, 300 internal +300 external 350 miles, 410 internal +300 external 650 miles.

The tactical tests of the P-51B-1 with 180 gallons of internal fuel have 13 minutes to climb to 25,000 feet, then 53 minutes to reach 220 miles out at 225 IAS (around 320 TAS), 20 minutes of combat, 32 minutes to return the 220 miles, landing with 20 gallons remaining. Going out was uphill? Add a pair of 75 gallon external tanks means 19 minutes to climb to 25,000 feet, then 2 hours to reach 600 miles out at 210 IAS (around 295 TAS), 20 minutes of combat, 1 hour and 34 minutes to return the 600 miles at 225 IAS (around 320 TAS), landing with 20 gallons remaining. The external 150 gallon ferry tank can be carried. P-51B-5 has the fuselage fuel tank, requiring the choice between a radio and IFF set.

The published combat radius figures are not consistent, the table being discussed at least gave the US figures for combat, take off and climb and distance covered in the climb, which was the point of posting them, plus since the altitude was given as well as the fuel allowances for combat and climb the range the cruise speed could be estimated from the range. At the moment the Spitfire long range profile has to use vertical climb and descent, the above gave some ideas on a more realistic profile. Data like below provides clues.

Speed 210 IAS at 25,000 feet.
1. Internal fuel only
2. Internal plus 2x150 gallon external.
a. Take off weight
b. Total fuel
c. Fuel Consumed in Gallons for 5 minutes War Emergency Power & 15 minutes Military Power.
d. Fuel Consumed in Gallons during Warm-up, Take-off, and Climb.
e. Horizontal Distance to Climb to 25,000 feet.
f. range

Note lack of fuel reserves. Table probably dated 20 November 1942, calculations, not flight tests.

1. P-39N, 7,500 pounds, 87 gallons, 52 gallons, 40 gallons, no fuel left.
2. P-39N, 9,600 pounds, 387 gallons, 52 gallons, 50 gallons, 58 miles, 848 miles.

Above for unmodified, below for modified P-39N.

1. P-39N, 7,700 pounds, 120 gallons, 52 gallons, 40 gallons, 38 miles, 156 miles.
2. P-39N, 9,800 pounds, 420 gallons, 52 gallons, 51 gallons, 61 miles, 1,078 miles.

1. P-40F, 8,850 pounds, 156 gallons, 45 gallons, 61 gallons, 65 miles, 283 miles.
2. P-40F, 10,950 pounds, 456 gallons, 45 gallons, 72 gallons, power required for 210 MPH exceeds power available.

1. P-38K, 16,900 pounds, 300 gallons, 111 gallons, 90 gallons, 43 miles, 296 miles.
2. P-38K, 18,600 pounds, 600 gallons, 111 gallons, 101 gallons, 54 miles, 958 miles.

1. P-38J, 16,300 pounds, 300 gallons, 111 gallons, 90 gallons, 42 miles, 298 miles.
2. P-38J, 18,400 pounds, 600 gallons, 111 gallons, 100 gallons, 52 miles, 967 miles.

1. P-38H, 15,900 pounds, 300 gallons, 111 gallons, 86 gallons, 40 miles, 326 miles.
2. P-38H, 18,000 pounds, 600 gallons, 111 gallons, 98 gallons, 50 miles, 1,005 miles.

1. P-47D, 13,500 pounds, 305 gallons, 89 gallons, 101 gallons, 57 miles, 473 miles.
2. P-47D, 15,600 pounds, 605 gallons, 89 gallons, 125 gallons, 81 miles, 1,045 miles.

1. P-51B, 9,050 pounds, 180 gallons, 58 gallons, 46 gallons, 50 miles, 415 miles.
2. P-51B, 11,150 pounds, 480 gallons, 58 gallons, 59 gallons, 80 miles, 1,570 miles.

1. P-63A-1, 7,770 pounds, 136 gallons, 53 gallons, 42 gallons, 35 miles, 235 miles.
2. P-63A-1, 7,770 pounds, 436 gallons, 53 gallons, 58 gallons, 64 miles, 1,216 miles.

1. Spitfire IX, 7,480 pounds, 102 gallons, 58 gallons, 29 gallons, 28 miles, 97 miles.
2. Spitfire IX, 9,580 pounds, 402 gallons, 58 gallons, 38 gallons, 43 miles, 1,263 miles.

Using this data the Spitfire VIII would have a range of around 310 miles on 149 gallons of internal fuel, 62 gallons at 4.6 mpg plus 28 miles less the penalty for around 300 pounds of extra fuel and tankage. The RAF figures in imperial/US gallons are 23/27.6 gallons take off and climb to 20,000 feet, 36/43.2 gallons for combat, range 304 miles no reserves.