Climb, Descent and Hold

Question 1

what is the green dot speed on an airbus

Answer 1

• the best L/D speed on an airbus

Question 2

When is Rate of climb greatest

Answer 2

when (power thrust - power drag) is maximum

Question 3

how does altitude, temp and weight affect climb gradients and rate of climb

Answer 3

• as PA increases, climb gradient decreases and rate of climb decreases.
• as temp increases, climb gradient decreases and rate of climb decreases.
• as weight increases, climb gradient decreases and rate of climb decreases.

Question 4

Where is the climb ceiling determined

Answer 4

where the a/c can only achieve 300 ft/min climb

Question 5

What are the climb speeds?

Answer 5

• 250kts below 10,000ft
• 300kts above 10,000ft
• M= 0.78 above the x over altitude

Question 6

how does TAS change at constant mach number in a climb

Answer 6

TAS will decrease, and vice versa in a descent

Question 7

what are the characteristics of cabin climb

Answer 7

• cabin rate of climb is limited to 1,000fpm on fly by wire aircraft
• cabin rate of climb will always be lower than the aircraft’s rate of climb

Question 8

when is descent gradient at it’s minimum

Answer 8

• when drag is minimum or when L/D ratio is maximum

Question 9

for a given aircraft weight ______

Answer 9

RoD is minimum when TAS x drag is minimum

Question 10

is the speed for lowest RoD higher or lower than L/D n

Answer 10

its lower (ref the graph)

Question 11

descent gradient at green dot speed is minimum or maximum

Answer 11

minimum

Question 12

if you want to descend at min rate, should you set a speed less than green dot speed

Answer 12

no because it’s not beneficial to descend at less than green dot speed

Question 13

how is cabin pressure changed for landing

Answer 13

• it’s optimized during descent, so landing field pressure is + 0.1 psi just before landing.

Question 14

what is the standard cabin descent rate

Answer 14

• is 350 ft/min by default but can be increased up to 750 ft/min (ON AN AIRBUS)

Question 15

What is a repressurisation segment, how does the aircraft manage a repressurisation segment

Answer 15

• when cabin descent time is longer than the aircraft’s descent time, a repressurisation segment is needed where the VS is limited (usually 2 mins)
• the aircraft will move it’s TOD back and set a thrust greater than idle, and will go to idle after the repressurisation segment

Question 16

What are holding speeds flown at

Answer 16

• green dot speed but initially flown at minimum drag.