Page:CAB Accident Report, Pennsylvania-Central Airlines Flight 143.pdf/36



On April 5, 1939, the Civil Aeronautics Authority specified in the operation limitations, which were made a part of the aircraft airworthiness certificate of NC 13359, that the engine maximums should be as follows:

By Aircraft Specification No. 558, issued by the Civil Aeronautics Administration on September 6, 1940, the following limitations on the use of Pratt & Whitney Wasp S1H1-G engines in Boeing Model 247D airplanes were specified:

Placard limits

Maximum, except take-off 8000 ft., 33.0 in. Hg., 2200 r.p.m. (550 h.p.) Sea level, 35.0 in. Hg., 2200 r.p.m. (550 h.p.)

Take-off (one minute) 35.5 in. Hg., 2200 r.p.m. (550 h.p.) 34.0 in. Hg., 2100 r.p.m. (510 h.p.)

On October 22, 1940, the engine maximums specified in the aircraft airworthiness certificate of NC 13359 were revised to be as follows: