ure FOD foreign object damage ft-lb foot-pound fps foot per second GE General Electric hd head Hg mercury HP horsepower HMU hydromechanical unit hr hour HUD heads up display Hz Hertz in inch lb pound LDS load-demand spindle LH left-hand man manifold MGT measured gas temperature microsec microsecond min minute MPH miles per hour N north NATO North Atlantic Treaty Organization OAT outside air temperature OD outside diameter ODV overspeed and drain valve OEI one engine inoperative PAS power-available spindle PDU pilot display unit PRT power recovery turbine PRV pressure regulating valve psi pounds per square inch psig pounds per square inch gage PT power turbine PTO power takeoff RAT ram air temperature res resistance RH right-hand RPM revolutions per minute s south SAT static air temperature SDC signal data converter SHP shaft horsepower TAT total air temperature TC top center TCP tricresyl phosphate TDC top dead center TEL tetraethyl lead temp temperature TGT turbine gas temperature TRQ torque VG variable geometry VIDS vertical instrument display system vs versus wt weight