Is it a D40-RA?

[SFRT - Frenchy]

Acording to the serial. What's more on the D40 compared to D30?

[whgates3]

according to the USAF, its a P-47d-40-RE

but the USAF never had too much experience w/ the P-47.
from 'The Dispatch' magazine, Volume 19, Number 3, Fall, 1994:
"In some "bubbletop" P-47Ds, the loss of the razorback resulted in severe tail flutter. The P-47D-40 introduced a small dorsal fin in front of the vertical stabilizer which eliminated the problem."

[Widewing]

Originally posted by whgates3
according to the USAF, its a P-47d-40-RE

but the USAF never had too much experience w/ the P-47.
from 'The Dispatch' magazine, Volume 19, Number 3, Fall, 1994:
"In some "bubbletop" P-47Ds, the loss of the razorback resulted in severe tail flutter. The P-47D-40 introduced a small dorsal fin in front of the vertical stabilizer which eliminated the problem."

 

This stability problem was well known in the P-47D-25-RE. This dorsal fin was introduced midway through the D-30-RE run, and many older aircraft were retrofitted with it in the field. Remember, the Evansville built aircraft (RA designator) were usually a few months behind in updates as compared to the Farmingdale built fighters (RE designator).

Nonetheless, this particular dorsal fin was still inadequate and was replaced with a more effective design in the P-47N.

My regards,

Widewing