Warbird Digest has just received the April, 2020 report from Chuck Cravens concerning the restoration of the Dakota Territory Air Museum’s P-47D Thunderbolt 42-27609 at AirCorps Aviation in Bemidji, Minnesota. We thought our readers would be very interested to see how the project has progressed since our last article on this important project. So without further ado, here it goes!
Update
While the essential measures which AirCorps Aviation has taken this month to protect employees from the Coronavirus outbreak have slowed progress on the P-47, they haven’t halted it. One consequence, however, was that we weren’t able to conduct our usual photo shoot to capture images as work took place. Thankfully, one of our expert technicians, Aaron Prince, did take some photos to document what he has been doing. Therefore this month’s update will consist mainly of detailed images of fuselage wiring, instrument panel work, and the armor plate installation.
We will also review the historical changes to the Thunderbolt’s design that first started appearing on the P-47D-23 variant (the kind we have under restoration).
Armor Plate
Instrument Panel
Aaron did a great deal of work on the complex instrument installation in the cockpit panel this month.
Wiring
The P-47 has unusually complex wiring for a WWII era fighter, because of the need to control the turbo supercharger in addition to regular instrument and control systems. This P-47 also had several components moved from their standard position as part of the field modifications involved with installing the ‘Christmas tree’ auxiliary fuel tank just behind the cockpit.
D-23 Changes
The P-47D-23 was the last of the Razorback Thunderbolts.
Both the Evansville, Indiana-built P-47D-23 and the all-but identical P-47D-22, which rolled off Republic’s Farmingdale, New York production line, incorporated several changes over previous models. The most visible difference was that both new variants now used 13 foot diameter paddle-blade propellers. The D-22 employed a Hamilton Standard Hydromatic 24E50-65 propeller, while the D-23 used a Curtiss Electric C542S. Interestingly, Curtiss Electric propellers used both symmetrical and asymmetrical blade shapes.
The new 13 foot paddle blade props were designed to take full advantage of the increased power available with water injection. However, they had the disadvantage of leaving only 6 inches of ground clearance on landings and take-offs.
The P-47’s rate of climb wasn’t an initial strong point in its performance envelope, so the 400 feet per minute gained with the paddle blade props was a definite improvement.
Another important improvement to the D-23 was the addition of a bullet-proof windshield and jettison-able cockpit enclosure; pulling a ring on the right, forward edge of the canopy pushed the cockpit enclosure back far enough for the slipstream to catch onto it and rip the frame off the Thunderbolt. The D-22/D-23 also had increased fuel capacity.
And that’s all for this month. We wish to thank AirCorps Aviation, Chuck Cravens (words and images) as well as Aaron Prince (images) for making this report possible! We look forwards to bringing more restoration reports on progress with this rare machine in the coming months, although it will likely be some time before we can do so given how the present pandemic has suspended almost all non-essential activities around the globe at the moment. Be safe, and be well!
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