DADE Aircraft Performance & Limitations 2 — Questions and Answers
Question 1: What is the effect of a wet or contaminated runway on aircraft accelerate-stop distance?
- It decreases stopping distance due to increased drag
- It significantly increases stopping distance due to reduced braking effectiveness (Correct answer)
- It has no effect if reverse thrust is used
- It only affects stopping distance above V1
Correct answer: It significantly increases stopping distance due to reduced braking effectiveness
A wet or contaminated runway reduces tire-to-runway friction, significantly increasing accelerate-stop distance and must be accounted for in dispatch performance calculations.
Question 2: When computing climb-limited takeoff weight, which condition results in the most restrictive climb gradient requirement?
- En route obstacle clearance
- Second segment climb with one engine inoperative (Correct answer)
- Final takeoff segment
- First segment climb
Correct answer: Second segment climb with one engine inoperative
The second segment climb (gear up, flaps in takeoff position, one engine inoperative) typically produces the most restrictive climb gradient requirement of 2.4% for three-engine aircraft and 2.7% for two-engine aircraft.
Question 3: How does a tailwind affect takeoff performance?
- It decreases ground roll but increases airspeed at liftoff
- It reduces lift-off speed
- It increases both ground roll and total distance to clear a 35-foot obstacle (Correct answer)
- It has no effect on obstacle clearance distance
Correct answer: It increases both ground roll and total distance to clear a 35-foot obstacle
A tailwind increases takeoff ground roll and total distance to clear obstacles because the aircraft must accelerate to a higher groundspeed to achieve the required airspeed.
Question 4: Under 14 CFR Part 121, what is the maximum allowable tailwind component that may be used for performance planning unless the AFM specifies otherwise?
- 5 knots
- 10 knots (Correct answer)
- 15 knots
- There is no regulatory limit
Correct answer: 10 knots
14 CFR Part 121.195 limits the tailwind component used in performance planning to 10 knots unless the AFM provides data for higher tailwind components.
Question 5: What does the term 'balanced field length' mean in aircraft performance?
- The runway length where accelerate-go and accelerate-stop distances are equal (Correct answer)
- A runway with equal upslope and downslope gradients
- The field length that allows equal margin for all obstacles
- A runway where V1 equals VR
Correct answer: The runway length where accelerate-go and accelerate-stop distances are equal
Balanced field length is the runway length at which the accelerate-go distance and the accelerate-stop distance from the same V1 are equal, optimizing the critical engine failure speed.
Question 6: Which factor does NOT affect an aircraft's maximum certificated landing weight?
- Structural load limits
- Tire speed ratings
- Brake energy absorption limits
- Fuel load at departure (Correct answer)
Correct answer: Fuel load at departure
Maximum certificated landing weight is determined by structural, brake energy, and tire limitations established during certification; the fuel load at departure is not a factor in the structural limit itself.
Question 7: What is the purpose of the 'net takeoff flight path' used in obstacle clearance analysis?
- It represents the actual aircraft flight path with all engines operating
- It is the gross flight path reduced by a specific gradient to provide a margin of safety (Correct answer)
- It defines the minimum altitude for obstacle identification
- It accounts for wind correction on the climb path
Correct answer: It is the gross flight path reduced by a specific gradient to provide a margin of safety
The net takeoff flight path is the gross flight path reduced by 0.8% for two-engine, 0.9% for three-engine, and 1.0% for four-engine aircraft to provide a margin of safety over obstacles.
DADE Aircraft Performance & Limitations 2
What is the effect of a wet or contaminated runway on aircraft accelerate-stop distance?