*
If any engine maintenance was done to any engine components on the replacement, intermix engine, but that engine was previously tested in a test cell before installation on the airplane, use the power plant test reference table in AMM 71-00-00/501 to find the test that is required.

Service Bulletins
An Boeing service bulletin (SB) is required for each airplane to intermix, substitute, interchange, derate or to change the takeoff thrust rating of the PW4084/PW4090/PW4098 engines. The reason a SB is required for engine intermix is to give the engine, power plant, and airplane modification and test instructions, for configuration control and to make sure that each airplane configuration is correct. There can be differences between similar 777 airplanes that would make incorporation of a SB on one airplane not correct for incorporation on another airplane.
A change request (CR) or master change (MC) is required to add an airplane or a group of airplanes into the effectivity of a current service bulletin or to create a new service bulletin, unless the airplane is delivered with the service bulletin effective for it. The CR process and MC process are used to make sure that the airplane flight manual (AFM) is updated for those airplanes that have engine intermix installed or airplanes that have revised the operational thrust settings. Each engine intermix combination and/or takeoff thrust rating requires documentation in the AFM. The various intermix and takeoff thrust combinations for an airplane will be in the appendices to the AFM. The airplane performance data for takeoff, climb, cruise and landing, which are affected by the operator selected takeoff thrust rating (or ratings), are in the AFM.
EFFECTIVITY BEJ ALL  72-00-00 
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ENGINE -INTERMIX, INTERCHANGE, SUBSTITUTION

A great amount of time can be required for Boeing engineering to research the changes for the engine intermix and to make the drawing changes to add airplanes to the effectivity of a service bulletin or to prepare a new service bulletin. Operators that need engine intermix, interchange, or substitution for their 777 airplanes should contact their Boeing Customer Engineering representative to get specific information.
EFFECTIVITY BEJ ALL  72-00-00 
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PW4000 SERIES ENGINES

777 AIRCRAFT MAINTENANCE MANUAL

POWER PLANT

EFFECTIVITY BEJ ALL  72-00-00 
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