Aircraft Performance Flashcards
What are some of the main elements of aircraft performance?
a) T/O and landing distance
b) Rate of climb
c) Ceiling
d) Payload
e) Range
f) Speed
g) Fuel economy
h) Maneuverability
i) Stability
What factors affect the performance of an aircraft during takeoffs and landings?
a) Air density
b) Surface wind
c) Runway surface
d) Upslope/downslope runway
e) Weight
What effect does wind have on aircraft performance on takeoff?
The effect of a headwind is to allow the aircraft to reach the lift-off speed at a lower ground speed, which will increase airplane performance by shortening the takeoff distance and increasing the angle of climb.
The effect of a tailwind is the aircraft needs to achieve greater ground speed to get to lift off speed. This decreases aircraft performance by increasing takeoff distance and reducing angle of climb.
What effect does wind have on aircraft performance on landing?
The effect of wind on landing distance is identical to its effect on takeoff distance. A headwind will lower ground speed and increase airplane performance by steepening the the approach angle and reducing the landing distance.
A tailwind will increase the ground speed and decrease performance, by decreasing the approach angle and increasing the landing distance.
What effect does wind have on aircraft performance on cruise flight?
Winds aloft will have a somewhat opposite effect on the airplane performance. Headwind = reduces ground speed, more fuel. Tailwind = increases groundspeed and less fuel
How does weight affect takeoff and landing performance?
Increased gross weight can have a significant effect on takeoff performance:
a) Higher liftoff speed
b) Greater mass to accelerate (slow acceleration)
c) Increased retarding force (drag and friction); and
d) Longer takeoff distance
What effect does an increase in density altitude have on takeoff and landing performance?
An increase in density altitude results in:
a) Increased takeoff distance (greater takeoff TAS required)
b) Reduced rate of climb (decreased thrust and reduced acceleration)
c) Increased true airspeed on approach and landing
d) Increased landing roll distance
Define the term “density altitude”
Density altitude is pressure corrected for non-standard temperature. Under standard atmospheric condition, air at each level in the atmosphere has a specific density, and under standard conditions, pressure altitude and density altitude identify the same level. Therefore, density altitude is the vertical distance above sea level in the standard atmosphere at which a given density is found.
How does air density affect aircraft performance?
The density of air has a direct effect on:
a) Lift produced by the wings
b) Power output of the engine
c) Prop efficiency
d) Drag forces
What factors affect air density?
a) Altitude - the higher the altitude, the less dense the air
b) Temperature - the warmer the air, the less dense it is
c) Humidity - more humid air is less dense
How does temperature, altitude, and humidity affect density altitude?
a) Density altitude will increase (low air density) when one or more of the following occur: high air temp, high altitude, high humidity
b) Density altitude will decrease (high air density) when one or more of the following occur: low air temp, low altitude, low humidity
Define the term “pressure altitude” and state why its important.
Its the altitude indicated when the altimeter setting window (barometric scale) is adjusted to 29.92. This is the altitude above the standard datum plane, a theoretical plane where air pressure (corrected to 15C) equals 29.92 in Hg. Pressure altitude is used to compute density altitude , true altitude, true airspeed, and other performance data.
