The establishment of a such varied validation criteria necessitated the requirement of a two engine test program. For example, the validation requirement for the cold buffer system required an endurance test at high power steady state whereas validation of the #4 bearing thrust load (bearing life) and improved burner can profile required a heavily instrumented test engine with short test durations in order to maintain instrumentation integrity. The engines used in the program were:
1. Endurance Test Engine-P411-FT8 Test Stand at Pratt & Whitney In East Hartford, Connecticut.
2. Instrumented Engine-P431-GG8 Test Gas Generator at Pratt & Whitney, East Hartford, Connecticut.
Endurance Test Engine-P411
Prior to the Phase II Program, P&W/TPM did not have a full load FT8 Test Cell. Testing was typically accomplished via a gas generator with an exhaust nozzle in an aircraft engine style test stand. To understand the influence of the ancillary systems and the power turbine on the Phase II improvements, P&W/TPM commissioned a full in factory "FT8 Site" complete with a PT8 power turbine, ancillary systems and a full load absorption capability making the test facility representative of a commercial FT8 installation. While the financial investment was substantial, it was required to achieve full Phase II validation. Figure 12 is a picture for the FT8 Full Load Test Cell.
In order to maximize the retrieval of quality data which represent long term service operation while minimizing test costs, P&W/TPM designed an endurance test which "accelerates wear" by running the unit more rigorously than typical commercial operation. The test protocol called for a 1200 hour endurance test which consisted of the following :
・1000 hours of peak load operation (base load combustor inlet temperature + 100°F)
・230 endurance cycles (see Figure 13)
・90°F Heated Compressor Inlet Temperature
・Elevated Oil System Temperatures
