Aircraft Performance Quiz Flashcards
What effect does high density altitude, as compared to low density altitude, have on propeller efficiency and why?
Efficiency is reduced because the propeller exerts less force at high density altitudes than at low density altitudes
If the outside air temperature (OAT) at a given altitude is warmer than standard, the density altitude is
Higher than pressure altitude.
Which combination of atmospheric conditions will reduce aircraft takeoff and climb performance?
High temperature, high relative humidity, and high density altitude
What effect, if any, does high humidity have on aircraft performance?
Decreases performance
What are the standard temperature and pressure values for sea level?
15C & 29.92” Hg
Which factor would tend to increase the density altitude at a given airport?
An increase in ambient temperature.
Which items are included in the empty weight of an aircraft?
Unusable fuel and undrainable oil.
How does an increase in weight affect takeoff performance, cruise performance, and landing distance?
Takeoff performance decreases, Cruise decreases, Landing distance increase
What is pressure altitude?
The altitude that is given when the altimeter is set to 29.92”Hg; altitude corrected for nonstandard pressure; height above standard datum plan
What is density altitude?
Altitude that the aircraft feels like it is flying at; density altitude is pressure altitude corrected for nonstandard temperature
What affect does a high density altitude have on aircraft performance and why?
The aircraft feels like it is flying higher than it actually is due to the air being less dense.
How do you calculate the Center of gravity?
Since W * A = M, we can rearrange this equation for A = M / W
What are the effects of a forward verses an aft CG assuming the same weight for either location?
Forward: Stall at higher speed, Higher elevator forces required, Lower cruise airspeed
Aft: Lower stall speed, Lighter elevator/control forces required, Higher cruise airspeed
Why does a forward CG. cause a decrease in cruise performance?
When the CG is more forward, more lift is required in order to maintain straight-and- level flight. Since more lift is required, we must increase our AOA. This increase in AOA also increases our induced drag, which overall, decreases performance
