TM 1-1510-224-10 APPENDIX B ABBREVIATIONS AND TERMS For  the  purpose  of  this  manual,  the  following  abbreviations  and  terms  apply.    See  appropriate  technical  manuals  for additional terms and abbreviations. B-1.  AIRSPEED TERMINOLOGY. V f e Maximum flap extended CAS Calibrated airspeed is speed is the highest speed indicated airspeed corrected for permissible with wing flaps in position and instrument error a airspeed corrected for position GS Ground speed is the speed of V 1c . Maximum landing gear the aircraft relative to the extended speed is the maxi- ground. mum speed at which an aircraft can be safely flown with the landing gear extended IAS Indicated airspeed is the craft can be safely flown with speed as shown on the air- the landing gear extended. speed indicator and assumes V₁₀ Maximum landing gear no instrument error. operating speed is the maximum KT Knots.   V_mca speed at which the landing gear can be safely extended or M_mo Mach number. The ratio of retracted. true airspeed to the speed of sound. V_mca The minimum flight speed at which the aircraft is direction- M_mo Maximum operating Mach ally controllable as deter- number. mined in accordance with Federal Aviation Regulations. TAS True airspeed is calibrated Aircraft Certification conditions airspeed corrected for include one engine altitude, temperature, pressure, becoming inoperative and and compressibility effects. propeller feathered; up to a 5° V₁ Takeoff decision speed bank toward the operative engine; takeoff power on V₅₀ Takeoff safety speed is the operative engine; landing gear speed at 50 feet AGL (35 feet up; flaps up; and most rear- AGL with one engine ward CG.  This speed has inoperative). been demonstrated to provide V_a Maneuvering speed is the satisfactory control above Maximum speed at which power off stall speed (which application of full available varies with weight, configuration application of full available , and flight attitude). aerodynamic control will not overstress the aircraft.   V_mo Maximum operating limit speed V_enr One engine inoperative Rotation speed. enroute climb speed. V_r V_f Design flap speed is the highest V_ref The indicated airspeed that speed permissible at the aircraft should be at when which wing flaps may be 50 feet above the runway in actuated. the landing configuration. B-1