P‑51B/C/D: Impacts of the 85‑gal rear fuselage tank & late‑war field installation status

[AMX32]

Hi everyone,

I’m hoping to gather some insight regarding the 85‑gallon rear fuselage fuel tank fitted to Merlin‑powered P‑51B, C and D Mustangs.

I would like to learn about its operational drawbacks and handling effects when full: center‑of‑gravity shift, maneuver restrictions, porpoising tendencies and related field fixes such as dorsal fin fillets.

Also I’m curious about its actual fitment status during the late European air war, circa late‑1944 through VE‑Day.
My impression is that once Allied air forces reached the borders of Germany, the Mustang already possessed sufficient mission radius relying solely on wing‑internal fuel plus drop tanks. In that later stage, did many front‑line units start to remove or de‑activate this fuselage tank in the field? Or was it still routinely retained on most airframes?

Primary‑source unit reports, pilot accounts or maintenance documentation would be especially helpful.
Thanks for any information you can share.

 

[AMX32]

Considering the operational distances in the Pacific theatre, especially the large number of long‑range escort missions, I believe the Mustang’s rear‑fuselage tank was probably not removed.

 

[windswords]

One thing about the P-51 that many dont know was that this was a very touchy thing with them because of the small/slender nature of the Mustang if it had too much internal fuel/ballast/weight sloshing around, it could severely affect its center of gravity, significantly hampering its usual litheness in combat and it flew a bit sluggish and shaky in that configuration, not desirable in combat. Some of the Mustang pilots I spoke with, depending on the mission and circumstances, if anticipating trouble, would actually start out on internal fuel to lessen that integral weight, then switch to wing tanks. In order to increase the Spitfire's dismal range, the same type of internal fuselage tank was used and the Spitfire pilot's manual warned against any "aggressive" manuevres, until the fuel was burned off in that tank. The P-47 was not significantly affected by full internal fuel loads, and could fight just as well with full internal tanks, another significant advantage over the much twitchier P-51s.

 

[AMX32]

One thing about the P-51 that many dont know was that this was a very touchy thing with them because of the small/slender nature of the Mustang if it had too much internal fuel/ballast/weight sloshing around, it could severely affect its center of gravity, significantly hampering its usual litheness in combat and it flew a bit sluggish and shaky in that configuration, not desirable in combat. Some of the Mustang pilots I spoke with, depending on the mission and circumstances, if anticipating trouble, would actually start out on internal fuel to lessen that integral weight, then switch to wing tanks. In order to increase the Spitfire's dismal range, the same type of internal fuselage tank was used and the Spitfire pilot's manual warned against any "aggressive" manuevres, until the fuel was burned off in that tank. The P-47 was not significantly affected by full internal fuel loads, and could fight just as well with full internal tanks, another significant advantage over the much twitchier P-51s.

Thank you very much for the information. This is the first time I have learned that the Spitfire had similar issues