51-09-01 PRATT & WHITNEY: Applies to Boeing Model 377 Aircraft Equipped With Wasp Major TSB3-G or B5 Engines Using Antidetonate (Wet Power) for Takeoff.
Compliance required as soon as possible but not later than May 1, 1951.
A. Each operator of an airplane covered shall select a power which he undertakes to maintain. If that power is less than the corresponding value available during the type certification tests of the airplane, the operating weights of the entire fleet shall be reduced to values such as will enable the airplanes to comply with the transport category performance requirements with the takeoff power selected. Appropriate flight manual revisions shall be made to indicate whatever changes in performance have resulted.
B. The power actually developed by each engine shall be measured each time it reaches each of the following stages:
(1) Upon installation of overhauled engines in aircraft;
(2) At the No. 3 inspection nearest to the midpoint ofthe authorized service time between overhauls; and
(3) At the nearest No. 3 inspection or some convenient point near or at, the end of the authorized service time between overhauls.
C. The procedures and methods employed in making these power measurements shall be acceptable to the FAA.
(1) The frequency of the power measurements should be continued as indicated above until the results obtained on each operator's fleet have been evaluated for the purpose of establishing whether more frequent or less frequent measurements are warranted;
(2) Operators not employing line maintenance practices which will reasonable insure the continued availability of the selected power will start this program making more frequent power measurements than indicated above.
D. An airplane incorporating an engine which at any of the required power measurements fails to develop the selected power shall not be dispatched unless:
(1) The power is restored to the selected value,or
(2) The engine is replaced by one developing the selected power, or
(3) The operating weights of the individual airplane are reduced as specified in A.
E. If, on a fleet-wide basis, the initial powers measured during any individual power measurement are consistently below the selected power, the operator shall:
(1) Initiate or improve line maintenance to the extent necessary to give reasonable assurance that the selected power is continuously available, or
(2) Make more frequent measurements of power, or
(3) Select a lower value of power representative of the initially measured values and reduce operating fleet weights as specified in A.
F. Results of the above power checks are to be submitted regularly and promptly to the assigned FAA Field Agents.