The P-38J and L in the European theater.

[Shortround6]

http://www.historynet.com/p-38-flunked-europe.htm

Unfortunately that story, while correct in some parts, perpetuates some of the anti-P-38 myths.
The pilots might have still froze but if the planes were flown at lower rpm and higher boost there may have been less trouble with turbochargers and the oil and the coolant and the fuel puddling in the intake manifolds. (the lead never came out, other compounds did, they were anti-knock compounds but they were not lead)
If, for example, you use more boost from the turbo, the intake temperature will be higher. If you raise the intake temperature 100 degrees the peak temperature in the cylinders goes up 100 degrees and the exhaust goes up 100 degrees. Now the higher boost used at cruise may not result in a full 100 degrees but you get the idea.
The article gives a couple of gas mileage figures but doesn't say at what speed or altitude. A P-38L could get around 3.3 mpg at 210mph indicated (over 300mph true) at 25,000ft while burning about 98 gallons an hour. 210mph indicated at 25,000ft was the standard speed the USAAF used for figuring combat radius. A MUstang was good for over 5 miles to gallon in such conditions.
Unfortunately the USSAF was operating it's P-38s against the wishes of both Allison and Lockheed and using high rpm and low boost. This burned more fuel than needed and helped keep the intake tract cold (there were other reasons). The Article mentions Lindberg in the Pacific but ignores Tony Levier going to Europe and telling the pilots there pretty much the same thing at about the same time (May/June?) of 1944. which helped but was a bit late.

However the article fails to mention that the P-38Gs, Hs and early Js only had 300 gallons of internal fuel in the fall 43/winter44 and it took a while for the Js and Ls with 410 gallons internal to show up. That 110 gallons was worth 200-300 miles of radius depending on exit speed.
The photo recon planes had a lot less trouble with engines, in part because they cruised faster (engines hotter) but the pilots may still have froze.

 

[fubar57]

I just posts' em(the links) and let you guys quibble about it. Thanks though.

 

[Shortround6]

Thanks for the link and your effort even if I do disagree with it

 

[tomo pauk]

Don't know for sure if this is true but I have read several times that the p38s continued to be teathered to the bombers on many missions for some time after the p47s and 51s were freed up to fly ahead of the bomber streems to break up German formations.
If this is true it would seem to account for some of the shortage of kills by p38s on early 44 missions. The pre L model p38s certainly had there shortcomings when it came to high altitude combat but certainly tactics like these didn't help matters.
It seems like of all the aircraft that needed to be able to range out ahead of the bomber streems to be effective it would be the p38 even more than other aircraft. That is to say being teathered to the bombers in an aircraft with dive limitations while German aircraft made firering passes then dive away is a non starter as far as effectiveness.

USAF didn't went immediately for the 'frei jagd', or loose escort.

 

[Navalwarrior]

The P-47 "clean" had roughly double the range of a Spitfire or 109 (also clean), it just wasn't enough to escort long range bombers.
But nobody had fighter that would escort a B-17 to it's max radius in 1942 or early 1943.

 

[Navalwarrior]

View attachment 512719

Con't:
I suspect the August 1943 range is for the P-47 with a single 75 US gal belly tank. I wish this chart included range updates for the larger tanks, as when the P-47D-15 RE became available.

 

[Shortround6]

Range and radius are not the same thing. Ranges usually do not include a combat allowance for one thing. I also doubt very highly that a Spitfire in May of 1943 was operating at a 175 mile radius without some sort of drop tank as the early Spitfires were operating at about a 120 mile radius when "clean".

 

[michael rauls]

Con't:
I suspect the August 1943 range is for the P-47 with a single 75 US gal belly tank. I wish this chart included range updates for the larger tanks, as when the P-47D-15 RE became available.

If my memory serves in the book " Americas hundred thousand" it lists that combat radius for the p47d 15 with 300 gallons external fuel as 570 miles so it would be just a few miles short of the p51s line on the map.

 

[BiffF15]

Yes would be nice to know the specifics, I.E. which drop tanks when and of how many gallons.

Cheers,
Biff

 

[tomo pauk]

If my memory serves in the book " Americas hundred thousand" it lists that combat radius for the p47d 15 with 300 gallons external fuel as 570 miles so it would be just a few miles short of the p51s line on the map.

Yes would be nice to know the specifics, I.E. which drop tanks when and of how many gallons.

Cheers,
Biff

<draws the book>

With 370 gals of internal fuel, plus 2x150 gal drop tanks, the 'bubble top' P-47D is supposed to have 600 miles of radius. Flight at 25000 ft, at 210 mph indicated air speed (~310 mph true air speed at that altitude, depending on temperature). Includes allowance for warm-up, take off, climb to 25000 ft, 5 min combat on WEP, 15 min combat on military power, and 30 min reserve. 305 gals internal + 2x150 gals ('razoback' P-47D) = 425 miles radius.
P-5B to K: 700 miles, with fuselage tank installed and 2x75 gal tanks, under same conditions.

<puts the book away, goes for the younger daughter to kindergarten>

 

[michael rauls]

I went and dragged out " Americas hundred thousand" and the graph/ text are a little unclear as to which sub model D it is referring to with which range. In the text it just references "early" and "late" p47 Ds. On a graph just above the range table the early p47s are grouped into p47c to p47d-22 and later p47s into p47d-23 to p47 d-40.
The range.table then lists two combat radius for the p47d. The first is on 370 gal internal fuel only and is 225 miles. The 2nd is with 370 gallons internal and 300 external and is actually listed as 670 miles.
I would note that the aproxamitly 80% increase in fuel is yielding about a 150% increase in combat radius (never noticed this discrepancy before)according to this table so something doesn't seem right here. Perhaps some of the members with more knowledge than I could shed some additional light on this.

 

[michael rauls]

<draws the book>

With 370 gals of internal fuel, plus 2x150 gal drop tanks, the 'bubble top' P-47D is supposed to have 600 miles of radius. Flight at 25000 ft, at 210 mph indicated air speed (~310 mph true air speed at that altitude, depending on temperature). Includes allowance for warm-up, take off, climb to 25000 ft, 5 min combat on WEP, 15 min combat on military power, and 30 min reserve. 305 gals internal + 2x150 gals ('razoback' P-47D) = 425 miles radius.
P-5B to K: 700 miles, with fuselage tank installed and 2x75 gal tanks, under same conditions.

<puts the book away, goes for the younger daughter to kindergarten>

Thanks for posting that. Which book did you draw that info from?

 

[Shortround6]

I went and dragged out " Americas hundred thousand" and the graph/ text are a little unclear as to which sub model D it is referring to with which range. In the text it just references "early" and "late" p47 Ds. On a graph just above the range table the early p47s are grouped into p47c to p47d-22 and later p47s into p47d-23 to p47 d-40.
The range.table then lists two combat radius for the p47d. The first is on 370 gal internal fuel only and is 225 miles. The 2nd is with 370 gallons internal and 300 external and is actually listed as 670 miles.
I would note that the aproxamitly 80% increase in fuel is yielding about a 150% increase in combat radius (never noticed this discrepancy before)according to this table so something doesn't seem right here. Perhaps some of the members with more knowledge than I could shed some additional light on this.

It has to do with the difference between "range" ( taking off and flying in a straight line and at perhaps a lower than operational height and then landing**)
and "Radius" which involves not only taking off and climbing to (probably a higher) altitude but a combat allowance of 15-20 minutes at perhaps double the fuel per minute of cruising, then the flight back and 20 minutes to one hour of reserve depending on which air force (US NAVY wanted one hour to find and land on the carrier). The part Tomo left out was that the drop tanks would be let go at the start of combat so the return flight is made on the internal fuel only after you take out the the fuel used for take-off and the combat allowance and allow for finding and airfield after you get back to England (or where ever).

** Some "ranges" are calculated by magically levitating the plane to 5,000 or 10,000ft and figuring how far it could fly on the available fuel, no allowance made for starting, warm up and take-off and climb to cruising height and no reserve at the end.

 

[Shortround6]

I would note that the addition of 65 gallons of internal fuel to the later P-47s made a for a significant jump in radius. They took off on internal fuel (the fuel supply was more secure) and switched to drop tanks at a "safe height", flaps and landing gear up and enough time to restart the engine if it quit when switching over to the drop tanks. Climb, forming up and cruise to target is done on the drop tanks. Main tank gets a trickle of fuel back from the overflow line form the carb/injector during flight but nobody relied on that but does help explain why they used 15-30 gallons out of the main before going to drop tanks. If main was full the any overflow fuel was vented overboard and wasted. SO combat starts with full (nearly) internal tanks and a P-47 could suck down 4-5 gallons a minute at military power. That extra 65 gallons was worth 20-25 minutes at "get out of Dodge City" speeds or over 100 miles.

 

[michael rauls]

It has to do with the difference between "range" ( taking off and flying in a straight line and at perhaps a lower than operational height and then landing**)
and "Radius" which involves not only taking off and climbing to (probably a higher) altitude but a combat allowance of 15-20 minutes at perhaps double the fuel per minute of cruising, then the flight back and 20 minutes to one hour of reserve depending on which air force (US NAVY wanted one hour to find and land on the carrier). The part Tomo left out was that the drop tanks would be let go at the start of combat so the return flight is made on the internal fuel only after you take out the the fuel used for take-off and the combat allowance and allow for finding and airfield after you get back to England (or where ever).

** Some "ranges" are calculated by magically levitating the plane to 5,000 or 10,000ft and figuring how far it could fly on the available fuel, no allowance made for starting, warm up and take-off and climb to cruising height and no reserve at the end.

The 670 mile combat radius with 370 gallons internal and 300 external is specified with mission profile of 5min fuel for warm up and take off, climb to 25,000 feet,cruise at 25,000 feet, drop external tanks, 5 min at combat power, cruise back at 25,000 feet, and fuel reserves 30 min at minimum cruise power.
The 225 mile figure given for internal fuel only has no specifics as to mission profile.
What you say makes sense but it seems the more rigorous specifics given for the combat radius with the external fuel example as opposed to no specifics at all for the internal fuel only example combat radius would result in a lesser percentage increase in combat radius per gallon aditional in the mission specified example not more. In other words the more things that are aloted for the mission profile, warm up, take off, climb out etc. the more one would expect to see a decrease in combat radius percentage increase in relationship to percentage increase in fuel compared to a figure with no specifics but we have the oposite dynamic here Thats why im kinda questioning the figures in this book on the p47s combat radius. Could be something im not getting here.(wouldn't be the first time) but doesn't seem right to me.

 

[tomo pauk]

I went and dragged out " Americas hundred thousand" and the graph/ text are a little unclear as to which sub model D it is referring to with which range. In the text it just references "early" and "late" p47 Ds. On a graph just above the range table the early p47s are grouped into p47c to p47d-22 and later p47s into p47d-23 to p47 d-40.
The range.table then lists two combat radius for the p47d. The first is on 370 gal internal fuel only and is 225 miles. The 2nd is with 370 gallons internal and 300 external and is actually listed as 670 miles.
I would note that the aproxamitly 80% increase in fuel is yielding about a 150% increase in combat radius (never noticed this discrepancy before)according to this table so something doesn't seem right here. Perhaps some of the members with more knowledge than I could shed some additional light on this.

The bigger main tank, 270 gals, was installed on the P-47D-25 and later A/C, including the -M and -N. Together with reserve tank, it meant 370 gals in the fuselage (= the only internal fuel on those -Ds and all -Ms). Earier -Ds, all -Cs and -Bs have had 205 gals in the main tank.
Major increase of range/radius due to small addition of fuel is to be expected - extra 65 gals will net a good flying distance in cruise setting. Eg. an extra ~40 min of flight at 25000 ft with P-47's engine still making healthy ~1150 HP.

Thanks for posting that. Which book did you draw that info from?

From "America's hundred thousand".

 

[Navalwarrior]

The bigger main tank, 270 gals, was installed on the P-47D-25 and later A/C, including the -M and -N. Together with reserve tank, it meant 370 gals in the fuselage (= the only internal fuel on those -Ds and all -Ms). Earier -Ds, all -Cs and -Bs have had 205 gals in the main tank.
Major increase of range/radius due to small addition of fuel is to be expected - extra 65 gals will net a good flying distance in cruise setting. Eg. an extra ~40 min of flight at 25000 ft with P-47's engine still making healthy ~1150 HP.



From "America's hundred thousand".

Resp:
Anyone have any dates when the first 'wet wing' P-47D-15s arrived in the ETO? Also, just a 'note' on range//combat radius; I know that around the 3rd quarter of 1943, either the 56th or 78th FG flew to bases closer to the west coast of England to refuel, just to get 10 min or so more flying time.

 

[Shortround6]

Drop tanks can get a bit weird because they only came in certain sizes. For the P-47 which seems to be the poster child for different drop tank set ups, you had that critical distance of how far you could get back out of "Dodge" (Germany) with the two two different internal tank setups. The question in 1943/early 1944 was hanging enough fuel under the plane to reach that distance that the 305 gallons internal allowed. Once you reached it it didn't matter how much more fuel you hung underneath, you were going to drop the excess fuel when you set up for combat (unless, perhaps, you had a small belly tank you kept when you dropped the wing tanks) Later in 1944 with the 370 gallons of internal fuel you could use some what bigger under wing tanks to reach the new max "return" distance.
there seems to have been a jump from 108-110 gallon tanks to 165 gallon tanks. I am not sure that either tank was an exact match ot the amount of return fuel.

 

[tomo pauk]

Resp:
Anyone have any dates when the first 'wet wing' P-47D-15s arrived in the ETO? Also, just a 'note' on range//combat radius; I know that around the 3rd quarter of 1943, either the 56th or 78th FG flew to bases closer to the west coast of England to refuel, just to get 10 min or so more flying time.

'Wet wing' usualy means that part(s) of the wing was/were sealed, in order to carry fuel internally in the wing itself.
The 1st P-47s with wing racks probably came to the UK in August 1943 by overflying Atlantic in stages. I don't know whether such P-47s (ie. with wing racks) were used inn the ETO in more than token numbers before 1944.

 

[michael rauls]

The bigger main tank, 270 gals, was installed on the P-47D-25 and later A/C, including the -M and -N. Together with reserve tank, it meant 370 gals in the fuselage (= the only internal fuel on those -Ds and all -Ms). Earier -Ds, all -Cs and -Bs have had 205 gals in the main tank.
Major increase of range/radius due to small addition of fuel is to be expected - extra 65 gals will net a good flying distance in cruise setting. Eg. an extra ~40 min of flight at 25000 ft with P-47's engine still making healthy ~1150 HP.



From "America's hundred thousand".

Ok thanks. I see the numbers you cited in the fuel systems section. I was just looking at graph/ table 34 which lists the total internal fuel capacity as 370 gal in both the internal fuel only combat radius example (225 miles)and the with 300 external gal of fuel example(670 miles). However the resulting range increase in the with external tanks example seems to iclude what would be resulting from the extra 65 gal internal in the later models without that being listed on the graph.
Perhaps a typographical error that slipped by the editing process.