A104 Airplane Performance Flashcards
explain the effects of weight on aircraft performance
Any item onboard adding weight is undersirable, more weight decreases overall performance, more weight=higher takeoff speed, longer runway, longer landing, shorter range, etc
effects of balance on aircraft performance
Center of gravity, center of gravity limits, center of gravity range, total aircraft moment
Center of Gravity
the balance point of an aircraft, also the center of mass.
center of gravity limits
the specified forward and aft points along the longitudinal axis within which the CG must be located during flight to keep it predictable
center of gravity range
the distance between the forward and aft CG limits
Total aircraft moment
the total weight of the aircraft multiplied by the distance between the datum line and the location of the CG of the aircraft
datum line
an imaginary ine in inches whicih all arm measurements are taken
arm
the horizontal distance in inches from the reference datum line to the item
moment
the product of the weight of an item multiplied by its arm, expressed in in pound, can be positive or negative
Aft CG*
Stall Speed-Lower, Stability-lower,
Cruise speed- Higher
Forward CG*
Stall speed- Higher
Stability- Higher
Cruise Speed- Lower
explain how atmospheric conditions effect aircraft performance*
The lifting capability of an aircraft depends upon the design of the wing, the speed at which the wing moves through the air, and the density of air. Airplane performance depends upon the number of air molecules available around the aircraft
three characteristics of air
air pressure, temperature, humidity
air pressure*
when air pressure is high, you have better performance.
Pressure altitude*(don’t confuse with air pressure)
How high are you in the air
temperature
Higher temperature= lower performance because the molecules become more energetic and molecules are more separated
humidity
Humid air weighs less than dry air. As humidity goes up aircraft performance goes down
Describe the characteristics of standard altitude
Sea level Barometric pressure of 29.92, sea temperature of 15 degrees Celsius, relative humidity of 0 percent, standard temperature lapse rate of 2 degrees Celsius per 1000 feet and 1 in of mercury per 1000 feet
Pressure altitude
is the height in the is a that corresponds to the currently sensed pressure around the aircraft
Density Altitude
is pressure altitude corrected for variations in temperature, and equals pressure altitude in a standard atmosphere
Performance speeds
Vspeeds (velocity)- speeds that define certain performance and/or limiting characteristics of an aircraft
Vso
The power-off stalling speed or the minimum flight speed at which the airplane is controllable in the landing configuration
Vs
the power-off stalling speed or the minimum steady flight speed at which the airplane is controllable in a specific configuration
Vfe
the highest airspeed permissible with the wing flaps in a prescribed extended position. This is due to the air loads imposed on the structure of flaps
Va
The design maneuvering airspeed. This is the maximum speed at which the limit load can be imposed without causing structural damage
Vno
The maximum structural cruising speed or the max airspeed for normal operation
Vne
The never exceed speed, may cause structural failure
Indicated airspeed
The speed of the airplane as observed on the AI, the airspeed without correction
true airspeed
the speed of the airplane relative to air mass in which it is flying. IAS is corrected for air density
Ground speed
The speed of the airplane in relation to the ground over which it is flying. TAS corrected for winds
Best Angle on climb (Vx)
The speed that delivers the greatest gain of altitude in the shortest possible horizontal distance
Best rate of climb (Vy)
the speed that delivers the greatest gain in altitude in the shortest possible time(best glide speed)
