# Performance

 What is Vx? Best angle of climbAircraft will gain the most amount of altitude over time65 kts What is Vy? best rate of climbaircraft will gain the most altitude in a given period of time75 kts What is Vr? Rotations speed (When the nose leaves the ground).55 kts What is Va? Design Maneuvering speedMaximum speed you can stall an airplane88-111 ktsAs weight increases, Va increases.As weight decreases, Va decreases. What is What is Vno? Maximum structural cruising speedUpper limit of green arcDO NOT EXCEED EXCEPT IN SMOOTH AIR126 kts What is Vfe? Max speed with flaps extendedUpper white arc103 What are the 4 left turning tendencies? Spiraling SlipstreamAsymmetric Thrust (P Factor)TorqueGyroscopic Precession What is Spiraling Slipstream? Rotating propeller produces backflow of air which wraps around the airplaneCauses a change in airflow around the vertical stabilizer - strikes the left side of vertical fin - causes the plane to yaw left What is Asymmetric Thrust (P Factor)? At a high angle of attack, the descending blade takes a greater bite than the ascending blade.Descending blade on right side makes the plane yaw to the leftMost pronounced with a high power setting and a high angle of attack What is Torque (in relation to left turning tendency of a plane)? Newton's 3rd law - for every action there is an equal and opposite reactionPropeller rotates clockwise - causes torque reaction - rotating the plane left about the longitudinal axis What is Gyroscopic Precession? Resultant is 90 degrees ahead of the actionEx. Pitch up, yaw rightEx. Yaw right, pitch down What is density altitude? Pressure altitude corrected for nonstandard temperatureIndicator of performance What is a stall? a rapid decrease in lift caused by the separation of airflow from the wing's surface brought on by exceeding the critical angle of attack What is an accelerated stall? Stall that occur with G-forces on an airplane What is the load factor? the ratio of the load supported by the airplane's wings to the actual weight of the airplane and its contents.The higher the load factor, the more lift required for the given weightn=L/Wn=load factorL=LiftW=Weight What is the limit load factor? he amount of stress or load factor that can be withstood before structural damage or failure occurs What is the lift to drag ratio? Lift divided by dragMeasures gliding efficiency of a plane. What is L/D max? the angle of attack that results in the least drag What form of drag is highest at low airspeed? Induced drag What form of drag is highest at High airspeeds? Parasitic drag What is CG? Center of GravityPoint in the plane where all of the weight is concentratedReference point for the three axis What occurs when a CG is forward? Longer takeoff and roll with higher angle of attack neededMore drag and lower stall speedmore stable at all speedseasier to recover stall/spin What occurs with a CG is aft? Shorter takeoff and roll with lower angle of attacklower drag and higher stall speedmore difficult to recover from stall/spin What is the center of pressure/lift? Point along the wing chord line where lift is concentrated What happens as the angle of attack changes? High AOA causes it to move forwardLow AOA causes it to move backward What is directional stability? Stability about the vertical axisVertical tail acts like a weather vanePlane must have more surface area behind the CG that it has in front of it When entering a side slip, What helps keep the airplane aligned with the relative wind? The greater the surface area behind the CG What is the keel effect? the steadying influence exerted by the side area of the fuselage and vertical stabilizer (low-wing aircraft). What is dihedral? Upward angle of the plane's wings with respect to the horizontal axis What is Sweepback? Design primarily to maintain the center of lift aft of the CG - creates lateral stability.If the airplane rotates about the vertical axis (yaws), For example yaws left the right wing has less sweep and a slight increase in drag, and the left wing has more sweep and less drag.Tends to force the airplane back into alignment with the relative wind. What is ground effect? Induced drag and excess speed in the flare may cause floating when within 1 wingspan above the surface Authordundane ID322008 Card SetPerformance DescriptionPerformance Updated2016-07-19T21:29:06Z Show Answers