Factors affecting Aircraft Performance Flashcards
Aircraft Performance
Ability of your airplane to accomplish certain things that makes it useful for a certain purpose.
* e.g. Takeoff, Landing, Cruising etc…
- To prevent inflight surprises
Factors Affecting Performance
Air Density
Weight
Wind
Aircraft performance (Runway)
Aircraft Configuration
Air Density
Biggest Aircraft Performance Factor
Airplane and Engine Performance depend on density.
* Wing, Engine & Propeller
Amount of air molecules in a given volume.
Layman’s term. “How thick the air is
Factors affecting Air Density
Altitude
Temperature
Humidity
Altitude, (Factors of Air Density)
- “As altitude increases, density/pressure decreases” Due to gravity.
- Air Becomes “thinner” as altitude is gained.
- As altitude increases, air mass decreases resulting to the decrease in Pressure & Density
“Higher the altitude, the lesser the air density, the lesser your aircraft will perform”
Temperature (Factors of Air Density)
- As temperature increases, air expands. If air expands, air density decreases.
- As temperature decreases, air compresses. if air compresses, air density increases.
“Higher the temperature, the lesser the air density, the lesser your aircraft will perform”
Humidity (Factors of Air Density)
- Amount of water vapor in the air.
- The more humid, more water vapor and less air molecules.
“Higher the humidity, the lesser the air density, the lesser your aircraft will perform”
6 Kinds of Altitude?
- Indicated Altitude - altimeter reading.
- Calibrated Altitude - corrected for instrument and installation error.
- Absolute Altitude - height from the field elevation.
- True Altitude - height from the mean sea level.
- Pressure Altitude - altitude from the standard atmosphere pressure of 29.92 inHg.
- Density Altitude - Pressure Altitude corrected for non-standard temp.
Pressure Altitude
- Altitude above the standard atmospheric
pressure of 29.92 inHg. - Indicated altitude when the altimeter
setting is set to 29.92 inHg. - Used in performance calculations.
Density Altitude
- Pressure altitude corrected from
non-standard temp. - Height/altitude measured in terms of the density of the air.
- In layman’s term “Density Altitude is the Altitude the Aircraft Feels that it is Flying”
“Higher the Density Altitude, the lesser the air density, the lesser your aircraft will perform”
Effects of High-density altitude
Cancel the density and you’ll get high altitude. High altitude means.
- Low Pressure
- Hot Temperature
- More Humid
- Higher Elevation
LOW AIR DENSITY = Poor Performance
Effects of Low density altitude
Cancel the density and you’ll get low altitude. low altitude means.
- High Pressure
- Cold Temperature
- Less Humid
- Lower Elevation
HIGH AIR DENSITY = Better Performance
Effect of Low Air Density to our Airplane
- There are less air molecules for interaction with the wing, therefore decreasing lift.
- Same goes with the propeller, which is also an airfoil
- There is less air for engine induction = Less Power Output
Altitude’s Effect on Air Density
- Air is less dense as you gain altitude.
- There is also a performance decrease due to thinner air.
- There is however, ONE improvement. True Airspeed Increases
Why true airspeed increases at higher altitude?
True Airspeed (TAS), The speed which your aircraft is ACTUALLY flying in the air
- How? Thinner air means less resistance, hence, less drag.
- However, your aircraft still maintains the same Indicated Airspeed (IAS)
Aircraft Weight, (Factors Affecting A/C Performance)
- More lift is required
- A higher fuel burn
- Longer takeoff distances
- Slower Climb (Poor climb performance)
- Less range
- Higher approach and landing speeds
- Longer landing distances
Wind, (Factors Affecting A/C Performance)
Wind significantly affects aircraft performance, with speed and direction impacting flight path, fuel efficiency, and the difficulty of takeoff and landing, requiring pilots to make adjustments and plan accordingly.
Take off Ground Roll
it is the distance an airplane will travel on the takeoff run from standing start until it leaves the ground
Take off Distance
it is the distance for the airplane to clear a 50 ft. Obstacle from standing start
Take Off Performance
(For Ground Roll/ Take Off Distance)
More Weight of Aircraft
* Increase Ground Roll/ Take off Distance
Higher Altitude
* Increase Ground Roll/ Take off Distance
Higher Temperature
* Increase Ground Roll/ Take off Distance
Wind
Headwind
* Decrease Ground Roll/ Take Off Distance
Tailwind
* Increase Ground Roll/ Take Off Distance
Runway Slope
Downslope Runway
* Decrease Ground Roll/ Take Off Distance
Upslope
* Increase Ground Roll/ Take Off Distance
Runway Surface
Soft ground / Unpaved / Dry grass
Increase Ground Roll/ Take off
VX (Best angle of climb)
- Most altitude gained for the least horizontal distance travelled
VY (Best rate of climb)
- Most altitude gained for the shortest amount of time
Service ceiling
- Aircraft will only climb at 100 feet per
minute (fpm).
Absolute ceiling
- Aircraft cannot climb anymore
