L-1011 Engine: RB.211 Reference Pressures

The RB.211 has a number of reference pressures that are interesting to know when programming the engine model.

• P1 - Probe forward of fan, reference for EPR system and pressure ratio control of fuel flow regulator (FFR)
• PF - Fan cold stream outlet; reference for EPR indicating system, Variable inlet Guide Vane (VIGV) and FFR Start Control Unit (SCU).
• P3 - Inlet of HP compressor; reference for pressure ratio control of FFR. 
• P4 - Output of HP compressor; reference for VIGV, SCU and pressure ratio control of FFR. 
• P8 - Outlet of hot stream gas generator; reference for EPR indicating system. 
• PS1 - Probe is aft of VIGV and IP case. Reference pressure used for VIGV scheduling.