P-51H Mustang Cancelled Developments

[RyanC]

I've been back at NARA II again, and I recently found this in an interesting document:



HEADQUARTERS, ARMY AIR FORCES
WASHINGTON

4 April 1945

MEMORANDUM FOR CHIEF, REQUIREMENTS DIVISION

SUBJECT: Fighter Cover for VLR Operations

[snip]

f. An automatic pilot will be in the P-47N's and subsequently in the P-51H.

[snip]

2. For your further information, the following projects are underway:

a. Installation of a Hammock Seat, a device which is hoped will materially lesson pilot fatigue.

b. Installation of thermos type containers for liquid nourishment.

c. Installation of an Anti-G suit with a valve which provides pulsation pressure (this provides massaging action to alleviate fatigue).

d. Collapsable rudder pedals which will enable the pilot to stretch his legs are being incorporated on all production P-47N's.

e. Under procurement from the Navy is a navigational computer used by Navy fighter pilots. This item was requested by the 301st Wing, and a basis of issue of one per pilot for that Wing has been requested.

f. Two (2) of the first seven (7) P-51H's are being modified to carry 305 gallons internal fuel. This is accomplished by increasing the capacity of the fuselage tank from 50 to 100 gallons. North American Aviation thinks that this aircraft, so modified, will be better balanced with respect to the CG than the present "D" series which incorporates the 85 gallon fuselage tank. This will give the airplane a radius of approximately 1400 miles, and if tests prove satisfactory, it is possible that all future P-51H's will be so modified.

S/
HENRY VICCELLIO
Colonel, Air Corps
Chief, Fighter & Air Defense Branch

 

[hesham]

Great info Ryan.

 

[Steve Pace]

Nice find, Ryan! -SP

 

[RyanC]

Here's what I think happened with this:

The 'Lightweight' Mustangs were designed for an ETO environment -- with the present P-51D's 85 gallon fuselage fuel tank being more than adequate for the ETO (people were flying to berlin and fighting and still having fuel left over) -- so they reduced it to 50 gallons for the Lightweight models; to get better performance against projected German super piston engined fighters ... and to have better takeoff characteristics when fully loaded.

But with V-E day; no more German super piston fighters; so all the lightweight mustangs using the 1,380 hp V-1650-11 get cancelled and development work centers back on increasing the range of the P-51H for the PTO.

VII Fighter Command (or 20th AF) wanted an all P-47N force; but got told, 'no, we don't have enough P-47Ns in the production schedule to do this, so P-51s will have to take some of the load'.

Cue the interest in the extended range P-51H with the 100 gallon fuselage fuel tank.

But then Japan surrenders in August '45 -- and with that, all the rationale for an extended P-51H disappears; and in peacetime, the higher 'prang' rate from a 100 gallon fuselage fuel tank becomes an important factor -- so no 100 gallon fuselage fuel tank is ever implemented on the production line.

 

[Steve Pace]

Makes sense, Ryan. BTW: Only 65 gallons was allowed in the 85-gallon fuselage tanks due to CG difficulties. -SP

 

[hesham]

Hi Ryan,


do you know from which patch ? ;


P-51H-1 series 44-64160/64179
P-51H-5 ,, 44-64180/64459
P-51H-10 ,, 44-64460/64714

 

[Tailspin Turtle]

Ryan - I'm glad to see that you're back researching in the Archives. Best of luck...

 

[RyanC]

From NARA II, a letter from 1944 regarding the 305 gallon P-51H, showing that it got started as an internal NAA proposal:

WAR DEPARTMENT
HEADQUARTERS OF THE ARMY AIR FORCES
WASHINGTON

15 September 1944

Subject Modification of Two P-51H Production Models
To: Director AAF Air Technical Service Command Wright Field, Dayton, Ohio
Attention: Materiel Command (Technical Executive)

1. A North American proposal to incorporate 305-gallons of internal fuel in the P-51H airplane should be investigated for further determination of the characteristics of subject model as a long range fighter.

2. Pursuant to such an investigation, it is directed that two (2) of the first seven production models of the P-51H be modified to incorporate an internal fuel capacity of 305 gallons, an automatic pilot and a hammock type seat.

By command of GENERAL ARNOLD:
SR BRENTNALL
Colonel, Air Corps
Chief, Production Branch, Materiel Div. Office of AC/AS, Materiel and Services

RIP Steve Pace. :-(

 

[Rickshaw]

Do you know anything about the license production agreement for the P-51H with the Commonwealth Aircraft Corporation in Australia? It is mentioned, briefly in Wikipedia. The RAAF decided to cancel its acquisition of the P-51H when the USAAF cancelled it.

 

[RyanC]

Hi Ryan,


do you know from which patch ? ;


P-51H-1 series 44-64160/64179
P-51H-5 ,, 44-64180/64459
P-51H-10 ,, 44-64460/64714

A surprise find today at the Archives gives me the serials of the two planned 305-gallon modifications:

44-64165 and 44-64166; from I guess, the P-51H-1 series.

 

[hesham]

Nice Info Ryan.

 

[Grey Havoc]

View: https://www.youtube.com/watch?v=fgIz5N11TZ8

 

[windswords]

View: https://www.youtube.com/watch?v=fgIz5N11TZ8

Greg's Airplanes and Automobiles is a great channel on Y-tube. His 8 part analysis on the P-47 is the best I've ever seen. If you haven't looked at his videos I heartily recommend them.