V-Speeds Reference for the Piper PA-38 Tomahawk

when corrected for instrument error. IAS values published in this handbook assume zero instrument error. Indicated Airspeed expressed in "Knots." Mach Number is the ratio of true airspeed to the speed of sound. True Airspeed is the airspeed of an airplane relative to undisturbed air which is the CAS corrected for altitude, temperature and compressibility. Maneuvering Speed is the maximum speed at which application of full available aerodynamic control will not overstress the airplane. Maximum Flap Extended Speed is the highest speed permissible with wing flaps in a prescribed extended position. REPORT: 2126 1-6 ISSUED: JANUARY 20. 1978 REVISED: NOVEMBER 2, 1981 PIPER AIRCRAFT CORPORATION PA-38-112, TOMAHAWK SECTION 1 GENERAL VNE/MNE VNO VS VSO Vx VY Never Exceed Speed or Mach Number is the speed limit that may not be exceeded at any time. Maximum Structural Cruising Speed is the speed that should not be exceeded except in smooth air and then only with caution. Stalling Speed or the minimum steady flight speed at which the airplane is con- trollable. Stalling Speed or the minimum steady flight speed at which the airplane is controllable in the landing configuration. Best Angle-of-Climb Speed is the airspeed which delivers the greatest gain of altitude in the shortest possible horizontal distance. Best Rate-of-Climb Speed is the airspeed which delivers the greatest gain in altitude in the shortest possible time. (b) Meteorological Terminology ISA OAT International Standard Atmosphere in which: The air is a dry perfect gas; The temperature at sea level is 15° Celsius (59° | Fahrenheit: The pressure at sea level is 29.92 inches Hg (1013 mb); The tempera- ture gradient from sea level to the altitude at which the temperature is -56.5°C (-69.7° F) is -0.00198°C (-0.003566°F) per foot and zero above that altitude. Outside Air Temperature is the free air static temperature obtained either from inflight temperature indications or ground meteorological sources, adjusted for in- strument error and compressibility effects. ISSUED: JANUARY 20, 1978 REVISED: OCTOBER 13, 1978 REPORT: 2126 1-7 SECTION 1 GENERAL PIPER AIRCRAFT CORPORATION PA-38-112, TOMAHAWK Indicated Pressure Altitude Pressure Altitude Station Pressure Wind (c) Power Terminology Takeoff Power Maximum Con- The number actually read from an altimeter when the barometric subscale has been set to 29.92 inches of mercury (1013 millibars). Altitude measured from standard sea-level pressure (29.92 in. Hg) by a pressure or barometric altimeter. It is the indicated pressure altitude corrected for position and instrument CITOI. In this handbook, altimeter instrument errors are assumed to be zero. Actual atmospheric pressure at field elevation. The wind velocities recorded as variables on the charts of this handbook are to be understood as the headwind or tailwind components of the reported winds. Maximum power permissible for takeoff. Maximum power permissible continuously during flight. Maximum tinuous Power Maximum Climb Power climb. Maximum Cruise Power power permissible during Maximum power permissible during cruise. (d) Engine Instruments EGT Gauge REPORT: 2126 1-8 Exhaust Gas Temperature Gauge ISSUED: JANUARY 20, 1978 PIPER AIRCRAFT CORPORATION PA-38-112, TOMAHAWK SECTION 1 GENERAL (e) Airplane Performance and Flight Planning Terminology Climb Gradient Demonstrated Crosswind Velocity Accelerate-Stop Distance MEA Route Segment The demonstrated ratio of the change in height during a portion of a climb, to the horizontal distance traversed in the same time interval. The demonstrated crosswind velocity is the velocity of the crosswind component for which adequate control of the airplane during takeoff and landing was actually demonstrated during certification tests. The distance required to accelerate an air- plane to a specified speed and, assuming failure of an engine at the instant that speed is attained, to bring the airplane to a stop. Minimum en route IFR altitude. A part of a route. Each end of that part is identified by: (1) a geographical location; or (2) a point at which a definite radio fix can be established. (f) Weight and Balance Terminology Reference Datum Station Arm Moment ISSUED: JANUARY 20, 1978 An imaginary vertical plane from which all horizontal distances are measured for balance purposes. A location along the airplane fuselage usually given in terms of distance in inches from the reference datum. The horizontal distance from the reference datum to the center of gravity (C.G.) of an item. The product of the weight of an item multi- plied by its arm. (Moment divided by a constant is used to simplify balance calcu- lations by reducing the number of digits.) REPORT: 2126 1-9 SECTION 1 GENERAL PIPER AIRCRAFT CORPORATION PA-38-112, TOMAHAWK Center of Gravity (C.G.) C.G. Arm C.G. Limits Usable Fuel Unusable Fuel Standard Empty Weight Basic Empty Weight Payload Useful Load Maximum Ramp Weight The point at which an airplane would balance if suspended. Its distance from the reference datum is found by dividing the total moment by the total weight of the airplane. The arm obtained by adding the airplane's individual moments and dividing the sum by the total weight. The extreme center of gravity locations within which the airplane must be operated at a given weight. Fuel available for flight planning. Fuel remaining after a runout test has been completed in accordance with govern- mental regulations. Weight of a standard airplane including unusable fuel, full operating fluids and full oil. Standard empty weight plus optional equipment. Weight of occupants, cargo and baggage. Difference between takeoff weight, or ramp weight if applicable, and basic empty weight. Maximum weight approved for ground maneuver. (It includes weight of start, taxi and run up fuel.) REPORT: 2126 1-10 ISSUED: JANUARY 20, 1978 PIPER AIRCRAFT CORPORATION PA-38-112, TOMAHAWK SECTION 1 GENERAL Maximum Takeoff Weight Maximum Landing Weight Maximum Zero Fuel Weight Maximum weight approved for the start of the takeoff run. Maximum weight approved for the landing touchdown. Maximum weight exclusive of usable fuel. ISSUED: JANUARY 20, 1978 REPORT: 2126 1-11