P-51 internal fuel capacity (how?)

[Elvis]

Which 'guy'. Charlie Neely for example is an absolute expert on the 51 in all its forms.

Oh now, don't be coy. Its alright. Email him.
...and who's "him"?
Whoever posted all that info at that site, some of which I've just quoted.
I assume its the site's owner, who may or may not be Curtis Fowles, but to be honest, I don't really know.



Elvis

 

[drgondog]

Oh now, don't be coy. Its alright. Email him.
...and who's "him"?
Whoever posted all that info at that site, some of which I've just quoted.
I assume its the site's owner, who may or may not be Curtis Fowles, but to be honest, I don't really know.



Elvis

Curtis knows his stuff. What uou quoted is correct info regarding the 'rule of thumb' to incorporate take off, landing and 30 minutes of buffer for the combat tanks (75/110). all I did was add the 150 gallon ferry tanks to your numbers (or Curtis) to show the greater range.

I also expanded a little on fuel management - which is far easier to do solo than on a leader's wing in formation

 

[Elvis]

Curtis knows his stuff. What uou quoted is correct info regarding the 'rule of thumb' to incorporate take off, landing and 30 minutes of buffer for the combat tanks (75/110). all I did was add the 150 gallon ferry tanks to your numbers (or Curtis) to show the greater range.

I also expanded a little on fuel management - which is far easier to do solo than on a leader's wing in formation

Oh, I never meant to imply your info was incorrect, only that some of your info was different from what I posted and that maybe the owner of the website might be interested in getting that info (on the chance that he didn't know that).
Whether you actually want to go through with that or not, is completely up to you.


Elvis

 

[drgondog]

Oh, I never meant to imply your info was incorrect, only that some of your info was different from what I posted and that maybe the owner of the website might be interested in getting that info (on the chance that he didn't know that).
Whether you actually want to go through with that or not, is completely up to you.


Elvis

If you have the link to the specific data link that Curtis posted I will go check it out.

 

[Elvis]

If you have the link to the specific data link that Curtis posted I will go check it out.

Actually, it was included in my initial post, but no need for all that scrolling.
Here ya' go - The P-51 Mustang Specifications -MustangsMustangs.com:


Elvis

 

[drgondog]

Actually, it was included in my initial post, but no need for all that scrolling.
Here ya' go - The P-51 Mustang Specifications -MustangsMustangs.com:


Elvis

It is correct - just doesn't tell you he is using the 110 (108 ) gallon long range tanks for his 269+220 (216) gallon fuel load and doesn't talk about ferry range.

I did note his top speed of "387 at 25K" for the P-51H is a misprint and just sent him an email.

 

[Elvis]

True, but he did mention that the total, w/tanks, was 489 gallons, so you could do the math.
Just another way of stating it. No wrong or right "procedure" here.

What's wrong with the top speed you mentioned?



Elvis

 

[drgondog]

True, but he did mention that the total, w/tanks, was 489 gallons, so you could do the math.
Just another way of stating it. No wrong or right "procedure" here.

What's wrong with the top speed you mentioned?



Elvis

it is about 100mph short at 387MPH from actual NAA tests at 25K w/o wing racks in Interceptor config.

Curtis says he is fixing it.

 

[Elvis]

Oh yeah, it does say 387 @ 25K ft.

I see its been changed to 487@25K ft.

Good eye ballers!



Elvis

 

[drgondog]

Oh yeah, it does say 387 @ 25K ft.

I see its been changed to 487@25K ft.

Good eye ballers!



Elvis

Thank you E. If I could proofread as well I would be happier.

 

[davparlr]

It is correct - just doesn't tell you he is using the 110 (108 ) gallon long range tanks for his 269+220 (216) gallon fuel load and doesn't talk about ferry range.

I did note his top speed of "387 at 25K" for the P-51H is a misprint and just sent him an email.

I believe that the data shown on mustangmustang reflects typical data on the mustang, I do not believe it reflects fairly the performance of the P-51 in fighter configuration, nor does it reflect the impact of 150 grade fuel, which was authorized in May, 1944, about the same time the D was in service, with a max boost of 75".

My estimate of the performance of the P-51B/C and the P-51D/K in June, 1944 is as follows (mustangmustang values are in italics):

Gross weight – full internal tanks, not including extended range tank (while this than in fact may have had some fuel, it typically was burned down first due to stability issues, also fighters stationed in France would probably not have this tank filled). Weight is based on data from "America's Hundred Thousand".

P-51B 9024 lbs 9800
P-51D 9611 lbs 10100

War Emergency HP – This is based on 75" of boost, which was authorized. While policy was to limit boost to 72", combat reports show 75" was used. This is based on AF test of 100/150 grade fuel (spitfireperformance site)

P-51B 1860 1720
P-51D 1860 1720

Maximum speed (without racks) – This is based on AF test of 100/150 grade fuel (spitfireperformance site). P-51D estimated from 67" boost.

P-51B 447 at 21K 439 at 25k
P-51D 441 at 26K 437 at 25k

Time to Climb to 20k (tested P-51B weight is 600 lbs heavier than combat weight. This is the correct weight for the P-51D). This is based on AF test of 100/150 grade fuel (spitfireperformance site)

P-51B 5.3 minutes (600 lbs heavy) 6.9
P-51D 5.3 minutes (correct weight) 7.3

Not covered by mustangmustang, but interesting still, is rate of climb at SL. This is based on AF test of 100/150 grade fuel (spitfireperformance site)

P-51B 4350 ft/min (600lbs heavy)
P-51D 4000 ft/min

I think this better defines the combat performance of the P-51 over Germany.

 

[davparlr]

Oh yeah, it does say 387 @ 25K ft.

I see its been changed to 487@25K ft.

Good eye ballers!



Elvis

I believe the 487 mph number, which is well reported, is incorrect. It appears this is from a NAA document that is a engineering analysis, not flight test (no a/c number or test points). Flight test data shows less performance. I would guess it is more in the 475 mph range.

 

[drgondog]

I believe the 487 mph number, which is well reported, is incorrect. It appears this is from a NAA document that is a engineering analysis, not flight test (no a/c number or test points). Flight test data shows less performance. I would guess it is more in the 475 mph range.

Dave - I once had my hands on the NAA Test Report written ~ March 1945, via Al White who was chief Test Pilot for the B-70 program. It did indeed state 487mph w/o racks, at 300 rpm and 90" hg. The flight test plot had ~ 10 values for 90"hg/3000 rpm (don't recall weight) and several were below 487 but only a couple of mph.

I am aware of the calc report as it is in Mike William' site.. I have recently contacted Boeing to see what I can obtain from the NAA files.

I don't know why the USAAF tests in 1946 achieved a lower test result but suspect some issues with the 1650-9
WI.

To your analysis above, are you basing your P-51B predictions on the 1650-3 (implied) or the 1650-7? If 1650-3 the top speed should be at 29K+ at 3000rpm/67" hg. Are you sure the -3 could take 72-75" boost?

The -9 in the P-51H was a beefed up -3 designed for 75-90".

 

[NeilStirling]

F-51H SAC figures http://www.alternatewars.com/SAC/F-51H_Mustang_SAC_-_22_March_1949.pdf

http://www.alternatewars.com/SAC/F-51H_Mustang_CS_-_22_March_1949.pdf

From here Standard Aircraft Characteristics Arcive

Neil.

 

[Mike Williams]

If 1650-3 the top speed should be at 29K+ at 3000rpm/67" hg. Are you sure the -3 could take 72-75" boost?

Hi Bill:

Please see: Project P.P.F. - Installation and Operating Instructions, 20 June 1944.

"Final release on Project P.P.F. has been made approving 70" manifold pressure for the P-38, 65" manifold pressure (with and without water injection) for the P-47, and 75" manifold pressure for the P-51 (both the 1650-3 and 1650-7 engines)."​

Hiya Neil: Nice!

 

[drgondog]

F-51H SAC figures http://www.alternatewars.com/SAC/F-51H_Mustang_SAC_-_22_March_1949.pdf

http://www.alternatewars.com/SAC/F-51H_Mustang_CS_-_22_March_1949.pdf

From here Standard Aircraft Characteristics Arcive

Neil.

Thanks neil - the 412kts works out to 472mph TAS and has racks - which takes another 10kts off the top end. That would place the SAC pilot handbook right with the NAA report for March 1945 for the p-51H without racks.

 

[drgondog]

Mike that answers the question about the -3 at 75". It is interesting to me that Packard allegedly beefed up the -3 to make the -9 but the -9 was designed for 90" so not so strange after all.

 

[davparlr]

Dave - I once had my hands on the NAA Test Report written ~ March 1945, via Al White who was chief Test Pilot for the B-70 program. It did indeed state 487mph w/o racks, at 300 rpm and 90" hg. The flight test plot had ~ 10 values for 90"hg/3000 rpm (don't recall weight) and several were below 487 but only a couple of mph.

I am aware of the calc report as it is in Mike William' site.. I have recently contacted Boeing to see what I can obtain from the NAA files.

I don't know why the USAAF tests in 1946 achieved a lower test result but suspect some issues with the 1650-9
WI.

I am overpowered by evidence! Great posts to all. I tend to be a doubter as piston powered aircraft approach 500 mph. That P-51H was fast!

To your analysis above, are you basing your P-51B predictions on the 1650-3 (implied) or the 1650-7? If 1650-3 the top speed should be at 29K+ at 3000rpm/67" hg. Are you sure the -3 could take 72-75" boost?

This issue has been overcome by later post, but the data I used from wwiiaircraftperfomance was from a P51B with a -7 engine. I do not know how many -3 engined P-51s were made or how long they were in use. I would indeed, like to know.

My point was that after May, 1944, the P-51B/D, at fighter weight, pulling 72-75" inches of boost, typically had better performance than is usually shown. This was the majority of the time the P-51 was engaged. As highly rated as the Fw-190D-9, a late war German aircraft, was, it was pretty well matched by the P-51B up to about 15k where the P-51's performance started to establish clear advantage, the P-51D was not far behind. Until the end of the war, the P-51 was not a plane to toy with in any theater.

 

[drgondog]

This issue has been overcome by later post, but the data I used from wwiiaircraftperfomance was from a P51B with a -7 engine. I do not know how many -3 engined P-51s were made or how long they were in use. I would indeed, like to know.

The P-51B-1 and -3 had the 1650-3 engine, and the -5 thru -15 were ordered with the 1650-3 but most were superceeded with the 1650-7 particularly in the ETO.

Dave - I don't have the complete facts regarding the date or the serial/block numbers when the 1650-7 was installed at the Inglewood and Dallas factories but believe it to be about January-February 1944. As the engines wore out in the earlier P-51B-1 and -3's, the 1650-3 engines were replaced with the 1650-7.. The 355th crew chiefs that are still around remember late spring 1944 as the last of the -3 for their Mustangs.

My point was that after May, 1944, the P-51B/D, at fighter weight, pulling 72-75" inches of boost, typically had better performance than is usually shown. This was the majority of the time the P-51 was engaged. As highly rated as the Fw-190D-9, a late war German aircraft, was, it was pretty well matched by the P-51B up to about 15k where the P-51's performance started to establish clear advantage, the P-51D was not far behind. Until the end of the war, the P-51 was not a plane to toy with in any theater.

Agreed. My fathers anecdotal observation was that he preferred his first Mustang (P-51B-7) with Malcolm Hood over the successive D models for pure performance... and by the time he was flying combat the jamming problem for the B-s had pretty much been alleveiated - at least he did not experience it.

 

[Mike Williams]

My point was that after May, 1944, the P-51B/D, at fighter weight, pulling 72-75" inches of boost, typically had better performance than is usually shown.

Hi Dave:

I agree with that assessment! I'd put the widespread conversion to 150 grade fuel and increase of boost at mid June 1944 though.