6. Factors Affecting Aircraft Perfromance

Question 1

Why can aircraft brakes get hot?

Answer 1

Residual thrust from a long taxi

Question 2

What can a pilot do to cool his brakes?

Answer 2

After take-off, the pilot may decide to leave the undercarriage down to cool the brakes

Question 3

Factors affecting Take Off Performance (9)

Answer 3

• TAKE-OFF MASS. (Load + A/C weight).
• POWER. Provided by Powerplant.
• ELEVATION OF AIRFIELD - Air Pressure calculations based on 1013.2hPa
• RUNWAY - Length/Slope/Constr/Contam.
• AIR TEMPERATURE - ICAO Std. 15’C
• WIND - Strength & Direction.
• NOISE ABATEMENT & ATC
• COMPANY INSTRUCTIONS
• SERVICABILITY

Question 4

Factors affecting Landing Performance (9)

Answer 4

• LANDING MASS - Load + A/C weight
• ELEVATION OF AIRFIELD - Air Pressure calculations based on 1013.2HPa
• RUNWAY - Length/Slope/Construction/Contamination.
• AIR TEMPERATURE - ICAO Std. 15°C
• WIND - Strength & Direction.
• ATC - Request to vacate early, etc
• COMPANY INSTRUCTIONS
• PILOT PREFERENCES
• AIRCRAFT CONFIGURATION

Question 5

Factors affecting Performance during climb

Answer 5

• MASS - Load + A/C weight
• SPEED
• WIND - Strength & Direction.
• CABIN PRESSURISATION
• AIR TEMPERATURE - ICAO Std. 15’C
• AIR DENSITY

Question 6

Factors affecting performance in the Cruise

Answer 6

• MASS - Load + A/C weight).
• CRUISING SPEED
• WIND - Strength & Direction.
• CABIN PRESSURISATION
• LEVEL

Question 7

What considerations should ATCOs give to AC requiring climb?

Answer 7

Give early climb instructions to an intermediate level.
Jet engines are not efficient at low levels. It costs money, and the public do not like the noise!

Question 8

What considerations should ATCOs make for AC in cruise?

Answer 8

Clear aircraft to requested levels ASAP!
It may be more economical for a pilot to take longer route, in order to get a desired flight level, especially on a fuel critical ‘leg’

Question 9

What considerations should ATCOs make at TOD?

Answer 9

Top of Descent
Pilots do not like to descend too early to a low
level. (due to fuel)
Pilots do not like a late descent, too much to do
in a short space of time.

Question 10

2 most common complaints by flight crews about economy and ecology?

Answer 10

Economics
- They are given long routings at low level.
- ATC applies poor speed control when they are in the landing configuration. This is high drag in makes fuel consumption very high.
Ecological
Noise and pollution are serious consequences of the long, low, high drag, high power approach to landing.

Question 11

What problems are associated with hydraulic failure? (5)

Answer 11

Flaps
Brakes
Rudder
Ailerons
Gear

Question 12

What effects do hydraulic failures have on previous stated controls?

Answer 12

Flaps
A lower angle, faster approach to landing, a faster
touchdown speed, needing the full length of the
runway.
Steering
Runway blocked
Weather
Cross winds, wind shear, fog, all make landing difficult.