December 9, 1942

LAC/17901

SUBJECT: Installation of R-2800 engines in C-69 Airplane

TO:   Commanding General
         AAF Material Center
         Wright Field
         Dayton, Ohio

ATTENTION: Chief, Experimental Engineering Section

THROUGH: AAF Resident Representative

1. The Lockheed Aircraft Corporation has been running a large number of engine tests on the Wright 3350 engine being installed in the C-69 airplane. Our experience with this engine to date has been very poor. Continual difficulties have developed due to the undeveloped state of the 3350 engine, resulting in high oil consumption and increased specific fuel consumption over the original Wright guarantees to Lockheed, nose gear case cracking and some ten to fifteen other difficulties with which the Air Force is, no doubt, familiar.

2. It is the intention of Lockheed to continue working with the Wright Company towards the development of the subject engine for installation in the C-69 aircraft. However, should the engine problems prove insurmountable without major redesign, the contractor feels that he should make a study of the installation of Pratt & Whitney R-2800 in the C-69. This would be only of a preliminary nature to guide our thinking in the future should other unforeseen difficulties arise.

3. Should we be caught with such a problem, the Lockheed Corporation would desire to purchase from some other manufacturer, or possibly our subsidiary, the Vega Aircraft Corporation, the 2800 Pratt & Whitney engine installation to be adapted to the C-69 as simply as possible. In this connection, we request the Air Forces to provide us with installation drawings and photographs of available R-2800 engine installations such as on the Curtiss Commando, the Douglas XA-26 or any others which might be suitable for installation in the C-69.

LOCKHEED AIRCRAFT CORPORATION

Hall L. Hibbard
Vice President & Chief Engineer
DEC 24 1942