*3C Determining Performance Limitations - Aircraft Performance

Question 0

1. What are some of the main elements of aircraft performance?
   (FAA-H-8083-25)

Answer 0

a. Takeoff and landing distance
b. Rate of climb
c. Ceiling
d. Payload
e. Range
f. Speed
g. Fuel economy

Question 1

2. What factors affect the performance of an aircraft during takeoffs and landings?
   (FAA-H-8083-25)

Answer 1

a. Air density (density altitude)
b. Surface wind
c. Runway surface
d. Upslope or downslope of runway
e. Weight

Question 2

3. What effect does wind have on aircraft performance?

FAA-H-8083-25

Answer 2

Takeoff—a headwind will increase the airplane performance by shortening the takeoff distance and increasing the angle of climb. However, a tailwind will decrease performance by increasing the takeoff distance and reducing the angle of climb. The decrease in airplane performance must be carefully considered by the pilot before a downwind takeoff is attempted.
Landing—a headwind will increase airplane performance by steepening the approach angle and reducing the landing distance. A tailwind will decrease performance by decreasing the approach angle and increasing the landing distance. Again, the pilot must take the wind into consideration prior to landing.
Cruise flight—winds aloft have somewhat an opposite effect on airplane performance. A headwind will decrease performance by reducing ground speed, which in turn increases the fuel requirement for the flight. A tailwind will increase performance by increasing the ground speed, which in turn reduces the fuel requirement for the flight.

Question 3

4. How does weight affect takeoff and landing performance?

FAA-H-8083-25

Answer 3

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 ground friction); and
d. Longer takeoff distance.
The effect of gross weight on landing distance is that the airplane will require a greater speed to support the airplane at the landing angle of attack and lift coefficient resulting in an increased landing distance.

Question 4

5. What effect does an increase in density altitude have on takeoff and landing performance?
   (FAA-P-8740-2)

Answer 4

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 (same IAS).
d. Increased landing roll distance.

Question 5

6. Define the term “density altitude.”

FAA-H-8083-25

Answer 5

Density altitude is pressure altitude corrected for nonstandard 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.

Question 6

7. How does air density affect aircraft performance?

FAA-H-8083-25

Answer 6

The density of the air has a direct effect on:

a. Lift produced by the wings;
b. Power output of the engine;
c. Propeller efficiency; and
d. Drag forces

Question 7

8. What factors affect air density?

FAA-P-8740-2

Answer 7

Altitude—the higher the altitude, the less dense the air.
Temperature—the warmer the air, the less dense it is.
Humidity—more humid air is less dense.

Question 8

9. How does temperature, altitude, and humidity affect density altitude?
   (FAA-P-8740-2)

Answer 8

a.	Density altitude will increase (low air density) when one or more of the following occurs:
•	High air temperature
•	High altitude
•	High humidity
b.	Density altitude will decrease (high air density) when one or more of the following occurs:
•	Low air temperature
•	Low altitude
•	Low humidity

Question 9

10. Know the following speeds for your airplane!
    VS0—Stall speed in landing configuration; the calibrated power-off stalling speed or the minimum steady flight speed at which the airplane is controllable in the landing configuration.
    VS1—Stall speed clean or in specified configuration; the calibrated power-off stalling speed or the minimum steady flight speed at which the airplane is controllable in a specified configuration.
    VY—Best rate-of-climb speed; the calibrated airspeed at which the airplane will obtain the maximum increase in altitude per unit of time. This best rate-of-climb speed normally decreases slightly with altitude.
    VX—Best angle-of-climb speed; the calibrated airspeed at which the airplane will obtain the highest altitude in a given horizontal distance. This best angle-of-climb speed normally increases with altitude.
    VLE—Maximum landing gear extension speed; the maximum calibrated airspeed at which the airplane can be safely flown with the landing gear extended. This is a problem involving stability and controllability.

Answer 9

A

Question 10

11. What information can you obtain from the following charts?
    (FAA-H-8083-25)

Answer 10

a. Takeoff charts—These allow you to compute the takeoff distance of the airplane with no flaps or with a specific flap configuration. You can also compute distances for a no flap takeoff over a 50-foot obstacle scenario as well as with flaps over a 50-foot obstacle. The takeoff distance chart provides for various airplane weights, altitudes, temperatures, winds, and obstacle heights.
b. Fuel, time, and distance-to-climb chart—This chart will give the fuel amount used during the climb, the time it will take to accomplish the climb, and the ground distance that will be covered during the climb. To use this chart, obtain the information for the departing airport and for the cruise altitude.
c. Cruise and range performance chart—This is designed to give true airspeed, fuel consumption, endurance in hours, and range in miles at specific cruise configurations.
d. Crosswind and headwind component chart—This allows for figuring the headwind and crosswind component for any given wind direction and velocity.
e. Landing charts—Provide normal landing distance as well as landing distance over a 50-foot obstacle.
f. Stall speed performance charts—These are designed to give an understanding of the speed at which the airplane will stall in a given configuration. Will typically take into account the angle of bank, the position of the gear and flaps, and the throttle position.

Question 11

12. Define the term “pressure altitude,” and state why it is important.
    (FAA-H-8083-3)

Answer 11

Pressure Altitude—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 15°C) equals 29.92 in. Hg. Pressure altitude is used to compute density altitude, true altitude, true airspeed, and other performance data.

Question 12

13. The following questions are designed to provide pilots with a general review of the basic information they should know about their specific airplane before taking a flight check or review.
    What is the normal climb-out speed? _____________
    What is the best rate-of-climb speed? _____________
    What is the best angle-of-climb speed? _____________
    What is the maximum flap extension speed? _____________
    What is the maximum gear extension speed? _____________
    What is the stall speed in the normal landing configuration? _____________
    What is the stall speed in the clean configuration? _____________
    What is the normal approach-to-land speed? _____________
    What is maneuvering speed? _____________”
    “What is red-line speed? ____________
    What engine-out glide speed will give you maximum range? _____________
    What is the make and horsepower of the engine? ________________ ________________
    How many usable gallons of fuel can you carry? _____________
    Where are the fuel tanks located, and what are their capacities? ________________ ________________
    Where are the fuel vents for your aircraft?
    ___________________________________
    What is the octane rating of the fuel used by your aircraft? _____________
    Where are the fuel sumps located on your aircraft? When should you drain them?
    _____________________________________________________
    What are the minimum and maximum oil capacities? ________________ ________________
    What weight of oil is being used? _____________
    What is the maximum oil temperature and pressure? ________________”
    “Is the landing gear fixed, manual, hydraulic or electric? If retractable, what is the backup system for lowering the gear? ________________ ________________
    What are the nosewheel turning limitations for your aircraft?
    _____________________________________________________
    What is the maximum allowable/demonstrated crosswind component for the aircraft? _____________
    How many people will this aircraft carry safely with a full fuel load? _____________
    What is the maximum allowable weight the aircraft can carry with baggage in the baggage compartment? _____________
    What takeoff distance is required if a takeoff were made from a sea-level pressure altitude? _____________
    What is your maximum allowable useful load? _____________
    Solve a weight and balance problem for the flight you plan to make with one passenger at 170 pounds.”
    “a. Does your load fall within the weight and balance envelope?
    _____________
    b. What is the final gross weight? _____________
    c. How much fuel can be carried? _____________
    d. How much baggage can be carried with full fuel? ___________
    e. Know the function of the various types of antennae on your
    aircraft. ____________________________________________”

Answer 12

A