Wasn't the P-51 the best escort fighter of the war?

[MiTasol]

I think this paragraph is the most important one and applies equally to the P-38 and P-51.

 

[33k in the air]

And lastly, there's this graphic, but unfortunately I don't recall from which publication it comes.

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[Geoffrey Sinclair]

The 23 July 1942 RAF Fighter Command Order of Battle has 310 squadron rearming with Spitfire Vc - Long Range. The designation Long Range continues into 1944, by then mostly for LF mark V squadrons. So it could be any 1943 Spitfire escort range is based on mark V, which had 40 miles more range than the mark IX and would use less fuel at full power. In 1942 the Spitfire V was in trouble over France, it was the main target, in 1943 with the Luftwaffe need to shoot down bombers and its pilots unable to distinguish between the mark V and IX until close, the mark V was doing better.

As of January 1944 external tanks for Spitfires being made were 30 gallon (Metal, wood, fibre) and 45, 90 and 170 gallon metal.

"relevant Spitfire VIII figures from the original sources quoting maximum weak-mixture power setting as 320 mph at 20,000 ft, consuming about 1.1 gallon per minute. This corresponds with an engine setting of 2,400 rpm, +4 lbs boost (66 gallons per hour). So this seems similar. From the same source, the RAF were allocating 23 gallons for take-off and climb to 20,000 ft, and 36 gallons for 15 minutes of combat, leaving 63 gallons for cruise. This gives an endurance of 57 minutes, or a range of 304 miles, for an escort radius of 152 miles." (no reserves)

So the following is based on an unrealistic flight profile of vertical climb, fast cruise all the way there and back, vertical descent, arriving with empty tanks.

People who have access to the relevant performance sheets can add the distance gains and losses for things like economic cruise to/from near enemy airspace, distance covered in the climb (Spitfire V with 170 gallon tank, 30 air miles covered climbing to 15,000 feet, 55 to 24,000 feet), extra distance covered in the descent, proper fuel reserves, external tank drag, formation flying etc.

The Spitfire V managed around 8.9 miles per gallon at maximum economical cruise, versus 5.7 at fast cruise (both at 15,000 feet)

Spitfire VIII with 122 gallons on board requires an extra 10 or so gallons to reach 175 miles escort range, with a 45 gallon external tank, 260 miles radius.

The mark IX with 85 gallons on board plus a 45 gallon external tank, 170 miles radius.

Or if you like, Spitfire IX enters combat with full internal tanks, uses 36 gallons in combat, leaving 49, able to fly 235 miles back to base, requiring a 72 gallon external tank to be at 235 miles from base.

For the mark VIII, it could be 415 miles from home entering combat on full tanks, needing 110 gallons of external fuel to get to 415 miles.

Remembering what the (unrealistic) flight profile is assumed to be.

Switching to what if for the moment, if Castle Bromwich was switched to mark VIII and the RAF was willing to use the 90 gallon external tank in combat, then under the mission profile the mark VIII radius would be 370 miles, the external tank being drained at 325 miles from base. Before any ideas of more internal fuel are considered.

The following is from Performance Tables of British Service Aircraft, Air Publication 1746, dated August 1939 but data includes 1940/41 aircraft. The ranges of fighters are shown as ranges on the fuel available, after deducting fuel used in 15 minutes at maximum power at sea level. This allowance is for warming up and climbing to operational height. Bomber ranges were calculated differently but come with the note they make no allowance for - (i) The effect of wind, (ii), The effect of formation flying, (iii) The use of full throttle over enemy territory. Fuel weights may be for different octane ratings. Note the drop in ranges between fast and economic cruise.

First Hurricane I Column, DH Propeller, second Hurricane I column Rotol Propeller.

Characteristic	Units	Hurricane I	Hurricane I	Hurricane IIA	Hurricane IIC	Spitfire I	Spitfire II	Spitfire V
Normal Weight	(Pounds)	6,629​	6,532​	7,014​	7,544​	6,255​	6,238​	6,460​
Cruising Speed	(m.p.h)	275​	272​	281​	278​	304​	314​	310​
Cruise Speed Height	Feet	15,000​	15,000​	15,000​	15,000​	15,000​	15,000​	15,000​
15 Minutes allowance	Range (miles)	340​	335​	314​	311​	415​	335​	335​
15 Minutes allowance	Endurance Hours	1.25​	1.22​	1.12​	1.12​	1.4​	1.07​	1.08​
Fuel	(for range, pounds)	435​	435​	489​	489​	484​	414​	389​
Fuel	(for allowance, pounds)	145​	145​	209​	209​	146​	191​	216​
Fuel	(Total, pounds)	580​	580​	698​	698​	630​	605​	605​
Fuel	(Total, Gallons)	77.5​	77.5​	97​	97​	84​	84​	84​
Per 100 pounds fuel	Miles	78.2​	77​	64​	63.6​	85.8​	80.9​	86​
Overload Weight	(Pounds)	6,768​	6,661​
Maximum Fuel (Cruise)	Speed (m.p.h)	275​	272​
Cruise Speed Height	Feet	15,000​	15,000​
15 Minutes allowance	Range (miles)	455​	445​
15 Minutes allowance	Endurance Hours	1.65​	1.64​
Fuel	(for range, pounds)	580​	580​
Fuel	(for allowance, pounds)	145​	145​
Fuel	(Total, pounds)	725​	725​
Fuel	(Total, Gallons)	97​	97​
Per 100 pounds of fuel	Miles	77​	78.2​
Maximum Fuel	Capacity (Gallons)	97​	97​	97​	97​
Maximum Fuel (Economical)	Speed (m.p.h)	180​	170 - 180	168 - 176	165 - 170	180 - 190	180 - 190	180 - 190
Cruise Speed Height	Feet	15,000​	15,000​	15,000​	15,000​	15,000​	15,000​	15,000​
15 Minutes allowance	Range (miles)	600​	600​	524​	500​	575​	530​	480​
15 Minutes allowance	Endurance Hours	3.35​	3.4​	3.12​	3​	3.1​	2.86​	2.6​
Fuel	(for range, pounds)	580​	580​	489​	489​	484​	414​	389​
Fuel	(for allowance, pounds)	145​	145​	209​	209​	146​	191​	216​
Fuel	(Total, pounds)	725​	725​	698​	698​	630​	605​	605​
Fuel	(Total, Gallons)	97​	97​	97​	97​	84​	84​	84​
Per 100 pounds of fuel	Miles	103.5​	103.5​	107​	102.5​	118.8​	128​	123​

 

[PAT303]

A simple solution to the Spitfires lack of endurance was to fit all MkVIII's and IX's with the 33G upper 42G lower rear fuselage tanks like the MkVXI and a drop tank, problem solved.

 

[PAT303]

Admiral Yamamoto disagrees. Of course, sixteen P-38 vs. six A6M2 is hardly fair odds,

They were specially prepared aircraft modified for that mission plus the pilots were advised by Charles Lindbergh on how to get the best economy possible. The P51 is the best VLR plane used in WW2

 

[drgondog]

For what it's worth, fighter escort ranges from the publication Eighth Air Force Tactical Development, August 1942 – May 1945 (p97):

View attachment 657146

Note that while the graphic shows the Feb. 1944 range of 475 miles being achieved with two 108-gallon tanks, the text says it was done with two 150-gallon tanks. I think the text number is a typo — it doesn't make sense to go from 425 miles with 150 gallons of extra fuel to only 475 miles with 300 extra gallons, or twice the external fuel load. But it does make sense to go from 425 miles with 150 extra gallons to 475 miles with 216 extra gallons.

ETA: The P-38 range is shown with 75- and 108-gallon drop tanks. But this publication, as well as Freeman's Mighty Eighth War Diary, state that only the 165-gallon drop tank was used by the P-38 on operations.

You have put your finger on the dilemma I faced when I decided to include Combat Radius in the book. The AAF Combat Radius charts published in Dean's AOHT are the charts prepared following flight tests at both Eglin and Wright Field. The challenge with the charts and narratives in the many 8th AF histories are a.) multiple contradictions, b.) Cannot be logically connected to the Pilot Operating Manual, c.) do not present the uniform assumptions inherent in planning an escort mission.

Two of the best sources of data for Combat Radius OPERATIONAL practice are Encounter Reports and Macrs - which establish a pattern of actual ranges assigned and executed. For the P-47D for example, Brunswick/Celle/Kassel/Stuttgart are 'outer limits' for both through May 1944. Berlin/Augsburg for P-38J, Posnan for P-51B. Even this example has to be examined with care as Stuttgart for P-47D might represent 56th FG on April 24 performing a Sweep, with 355th and 357th FG P-51Bs escorting (and fighting) for 35-40 minutes around Munich, nearly to Austria.

The Most important assumption is the calculation of fuel consumed from INTERNAL tankage for the 5 minutes of WEP and 15 minutes of MP, coupled with ejection of drop tanks when entering combat. The most common data for such combat fuel consumption are from the engine manufacturers P&W, Allison and Merlin/Packard and are 1. 111 gal for P-38H/J, 2.) 89 for P-47C/D, c.) 58 from P-51B. The second set of values for 30 min reserve are 1. 50gal for P-38, 40 gal for P-47 and 26 gal for P-51.

The AAF Charts are Conservative in this respect - they are for single aircraft, not formations in which additional fuel consumption is required to transform a combat unit from one to 48+ before climbing. Second, and not often stated, is that there is a difference between Penetration/Withdrawal Escort in which the time cruising with bombers is at reduced speed over straight line progress to maintain position versus fly a sweep or straight to the target for R/V and escort for 15-30 minutes before straight line cruise home.

The second chart does discuss the differences but like the first, brings no assumptions nor differentiates by time, field mods/new production articles which added internal tankage. P-51B 85 gal fuse tank +46%), P-38J 110 gal LE tank (+36%), P-47D-25 65 gal main tank (+21%) increases respectively.

This is one of those situations where I say 'take what you want, and leave the rest'..

 

[drgondog]

And lastly, there's this graphic, but unfortunately I don't recall from which publication it comes.

View attachment 657149
.

You found it. Where? mine was hard copy in NAA files from folder with the NAA Field Service Bulletin NA-73/95 85 gallon fuselage Kit delivery forecast.

 

[Shortround6]

They were specially prepared aircraft modified for that mission plus the pilots were advised by Charles Lindbergh on how to get the best economy possible. The P51 is the best VLR plane used in WW2

Yamamoto was shot down on April 18 1943.
Most sources say Lindbergh left the US to go to the Pacific on April 24 1944, just over 1 year later.
Sources say he flew his first mission in a P-38 on June 27th 1944 with 475th fighter group.
This was after 13 (?) Missions in Corsairs.

 

[Ovod]

They were specially prepared aircraft modified for that mission plus the pilots were advised by Charles Lindbergh on how to get the best economy possible. The P51 is the best VLR plane used in WW2

As is any Spitfire fitted with extra fuel tanks to complete its mission.

 

[FLYBOYJ]

They were specially prepared aircraft modified for that mission plus the pilots were advised by Charles Lindbergh on how to get the best economy possible. The P51 is the best VLR plane used in WW2

The only modification that was done to the aircraft on the Yamamoto mission was the use of larger drop tanks and the mission leader John Mitchell had a navy compass installed in his aircraft. As stated, Lindberg did not provide any training to the folks who flew the Yamamoto mission (339th and 347th FS)

 

[GrauGeist]

The 18 P-38s that flew "Operation Vengeance" were standard P-38Gs.
No special prep (other than the USN compass fitted to Mitchell's P-38 as Joe mentioned) was done to the flight.

They were each equipped with one 165 gallon drop tank and one 330 gallon drop tank for the mission.

 

[33k in the air]

Two of the best sources of data for Combat Radius OPERATIONAL practice are Encounter Reports and Macrs - which establish a pattern of actual ranges assigned and executed. For the P-47D for example, Brunswick/Celle/Kassel/Stuttgart are 'outer limits' for both through May 1944. Berlin/Augsburg for P-38J, Posnan for P-51B. Even this example has to be examined with care as Stuttgart for P-47D might represent 56th FG on April 24 performing a Sweep, with 355th and 357th FG P-51Bs escorting (and fighting) for 35-40 minutes around Munich, nearly to Austria.

Definitely — what was actually done on operations is the best indicator. As far as I'm aware, those reports are not available online in any systematic was as are the RAF squadron ORBs. Otherwise, I'd have even more things to read!

You found it. Where? mine was hard copy in NAA files from folder with the NAA Field Service Bulletin NA-73/95 85 gallon fuselage Kit delivery forecast.

It's mentioned here (not too far down the page) — the descriptor below the image lists the origin. I downloaded the image from that site, and did some searching to see I could locate the originating document online.

 

[33k in the air]

The 18 P-38s that flew "Operation Vengeance" were standard P-38Gs.
No special prep (other than the USN compass fitted to Mitchell's P-38 as Joe mentioned) was done to the flight.

They were each equipped with one 165 gallon drop tank and one 330 gallon drop tank for the mission.

Regarding that operation, the YouTube channel WW2TV did an interview with Dick Lehr, author of Dead Reckoning: The Story of How Johnny Mitchell and His Fighter Pilots Took on Admiral Yamamoto and Avenged Pearl Harbor.

It's an hour and 16 minutes, and can be watched here.

 

[Admiral Beez]

Is there anything the P-51 was deficient in with regards to its escort fighter role?

Yes the P-47 had longer range than the P-51, but the former cost US $83k vs. US $51k for the Mustang. If the P-47 costs more, may be slower to produce and has more range than necessary, I'd say the P-51 wins.

 

[drgondog]

Definitely — what was actually done on operations is the best indicator. As far as I'm aware, those reports are not available online in any systematic was as are the RAF squadron ORBs. Otherwise, I'd have even more things to read!




It's mentioned here (not too far down the page) — the descriptor below the image lists the origin. I downloaded the image from that site, and did some searching to see I could locate the originating document online.

Wow - The ChicagoBoyz have not performed much personal research into the Arnold history or narrative and give undeserved credit to Wright Field Material Command for 'driving' the combat tank development. One of Arnold's top priorities in the Jauary-Feb 1942 Fighter Conference was to prioritize Combat Tanks and improve internal fuel capacity for existing fighters. Those turkeys actually believe Wright Field engineers drove development of external fuel tankage, when in fact they dragged their feet through 1942 and early spring 1943 Arnold tasked his Deputy Maj Gen Barney Giles to go take names and kick ass but have the long-range escort solution Jan 1 1944". He visited NAA, Curtiss, Lockheed, Bell and Republic to convey urgency in early June 1943. By that time his earlier initiatives had accelerated combat tank development and testing on 60 gal and 75 gal had been completed and set into production. Lockheed (P-38E Dec/1941, A-36 Oct 1942) already designed and incorporated external wing racks and plumbing for combat fuel tanks on their Own initiative.

Kelsey does receive appropriate credit for his role at Lockheed, but NAA as the specifier for the A-36 did all the preliminary work on external wing rack capability with internal funding - ditto the 90 gal steel prototype P-51B-1 fuselage fuel tank which first flew in July 1943. Col Ben Bradley at MC should receive credit for expediting approvals for NAA proposals for 85 gal tank, six gun wing and bubble canopy project approvals.

Given the dating and tone of the blog I wonder if Greg Pascal drew on their 'lens' for his rant about politics stifling LR escort development? Wright Field was NOT an energetic 'enabler' of the LR escort solution, save Kelsey's undercover funding approval at Lockheed. If you want to direct credit - send it Barney Giles direction. Kesley was long gone from Wright Field after the Jan 1942 Fighter Conference and completely out of the loop for 55 gal LE tanks for P-38, 85 gal fuse tank for P-51B and additional 65 gal main tank for P-47D-25.

General Echols in the meantime was twiddling funding and resources toward the GM P-75 as 'his solution'.

 

[wuzak]

Yes the P-47 had longer range than the P-51,

It did?

 

[Admiral Beez]

It did?

This website says so, P-47 vs P-51: America's Best WWII Fighter? | International Aviation HQ but info on the interest is often worth what we pay for it.

 

[33k in the air]

Edit fail on my part. D'Oh!

See subsequent post.

 

[Jabberwocky]

The 175 mile radius is stated in these two maps: picture, picture2. Unfortunately, it does not state the fuel tankage.
This map shows 200 mile radius; again, the fuel tankage of the Spitfire is not stated.

My take is that 90 imp gal (110 US gal) tank was the only addition for the 84 gal internal fuel tankage for the Spitfire for such calculations. Equals obviously to 174 imp gals, vs. 150 imp gals for the P-51B without fuselage tank and without drop tanks.

Not sure about that. Economical air cruising range for a Mk V was 465-500 miles (depends on engine and max approved boost) and for a Mk IX with a Merlin 66 at +18lbs was 434 miles (450 miles for the Merlin 61 version).

Spitfire LF IX November 1943 data card gives max still air range of 724 miles with a 45 gal tank at most economical after allowing for take off and climb to 20,000 ft (685 miles if tank is retained), and 387 miles at maximum weak mixture power. Same data card gives 980 miles max range with the 90 gallon tank (900 miles if tank is retained) and 520 miles at maximum weak mixture power.

As I understand it, RAF practice was that practical combat radius was between 33% and 40% of maximum still air cruising range (i.e. most economical power). After allowances for take-off/climb, combat power and reserves, the variance mostly depended on how much time was allocated for operating at most economical cruising power vs how much time was spent at 'fast cruising' - which was maximum weak/maximum continuous power.

I'd argue that for Europe in 1942 to 1944 all Spitfire needs is the 45 gallon slipper tank for a true 200 mile effective combat radius (possibly only a 30 gal tank).

 

[33k in the air]

Yes the P-47 had longer range than the P-51 . . .

Given the relative air miles per gallon each aircraft achieved, that is all but impossible. At least on internal fuel only.

This website says so, P-47 vs P-51: America's Best WWII Fighter? | International Aviation HQ but info on the interest is often worth what we pay for it.

It's never a good sign when the table of data comparing the two aircraft contains obvious errors. Look at the armament row — it shows the same info for both.

Even being charitable and saying the P-47 entry was just an accidental duplication of the P-51 data, the P-51D figure isn't right anyway. The ammo load of the P-51 was 400 rpg for the two inboard guns, and 270 rpg for the four outboard guns, or 1,880 rounds in all. (In some official sources I've seen it stated early P-51Ds had 500 rpg for the two inboard guns, which was subsequently lowered to 400.)