Contents:
(资料图)
Factors of Aircraft Performance
Factors of Takeoff and Landing Performance
Calculating Takeoff and Landing Performance
Factors of Climb Performance
Calculating Climb Performance
Factors of Cruise Performance
Calculating Cruise Performance
1. Factors of Aircraft Performance
Aircraft Performance
Determine:
How much runway you need for takeoff
Whether you can safely clear obstacles on departure
The amount of fuel you need
How much runway you need for landing
Table Performance Chart
Graph Performance Chart
Interpolation
Round out for more conservative figures
Effects of Air Density
Reduced air density = reduced aircraft performance
Longer takeoff roll
Dimished propeller efficiency
Variables that decrease air density:
Low pressure
High temperature
High humidity
Density Altitude
Pressure altitude: Altitude corrected for nonstandard pressure
Density altitude: Pressure altitude corrected for nonstandard temperature
At standard temperature, pressure altitude = density altitude
When the actual temperature exceeds the standard temperature, the density altitude can be substantially higher than the field elevation; aircraft performs as though they were at the higher elevation
Effects of Density Altitude
High, hot and humid = high density altitude
Calculating Density Altitude
Find the pressure altitude correcting for nonstandard pressure
Subtract the conversion factor from the field elevation to determine the pressure altitude
Locate the temperature at bottom of the chart and move up until you intercept the diagonal pressure altitude line
Move left and find the density altitude
2. Factors of Takeoff and Landing Performance
Aircraft Weight
Aircraft Flap Configuration
Takeoff - greater lift
Landing - reduced approach speed, steepened glide path, and lower touchdown speed
Headwind Component
Reduce takeoff ground roll
Shorten the landing roll
Tailwind Component
Much more takeoff distance
A 9 knots headwind reduces the takeoff distance by 10 percent
A 9 knots tailwind increases the takeoff distance by 45%
Smaller effects on landing distance
Crosswind Component
Depends on its net wind
Determining Headwind and Tailwind Components
Runway Gradient
Usually expressed as a percent
Positive gradient is unfavorable for takeoff
Positive gradient is favorable for landing
Negative gradiant decreases takeoff distance
Negative gradient increases landing distance
Runway Surface
Performance data is based a paved, level runway with a smooth, dry surface
Adjust the takeoff and landing distances for any other runway surface
3. Calculating Takeoff and Landing Performance
Takeoff Performance Table
Takeoff Performance Graph
Landing Performance Table
Landing Performance Graph
4. Factors of Climb Performance
Climb Airspeeds:
Best angle-of-climb (Vx)
Used for obstacle clearance immediately after takeoff
Provides the greatest altitude gain in the shrtest distance
Best rate-of-climb (Vy)
Used when aircraft has cleared all obstacles after takeoff
Provides the greatest altitude gain in a given time
Cruise climb airspeed
Generally higher than Vx or Vy
Better engine cooling
Better forward visibility
Better forward speed (reduced time enroute)
Absolute Ceiling and Service Ceiling
As altitude increases:
Vy increases
Vy decreases
Absolute ceiling is:
Where Vx and Vy meet
The point beyond which the aircraft cannot climb
Service ceiling is:
The altitude beyond which an aircraft can climb no more than one hundred feet per minute
5. Calculating Climb Performance
Climb Performance Table
Climb Performance Graph
6. Factors of Cruise Performance
Cruise performance charts enable you to predict:
Rate of fuel consumption
True airspeed
Range
Endurance
Trade-offs include:
Time
Power
Fuel consumption
Speed
Range
Three Main Cruise Airspeeds
Maximum level flight airspeed
Occurs when the force of total drag equals the force of full thrust
Further acceleration in level flight is not possible even with full power
Maximum range airspeed
Enables you fly the greatest distance per gallon of fuel
Produces minimum total drag and the highest lift to drag ratio
Maximum endurance airspeed
Enables the aircraft to remain aloft for the longest period of time
Achieves the minimum fuel use per hour
7. Calculating Cruise Performance
Cruise Power Setting Table
Best Power Mixture Range Graph
Setting Engine Performance Table
Cruising True Airspeed Graph
