Thrust Changes during approach (AIRBUS) ?
Joined: Mar 2005
Posts: 1,338
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From: Uh... Where was I?
I guess it depends on the circumstances.
Let's say a day with little wind gradient: GS mini will give a gradually diminishing speed until you reach VAPP. As compared with a constant selected speed at VAPP, there will be little difference. In the first case, thrust will change little, as the loss of energy due to less headwind will be roughly what the airplane needs to reduce speed and maintain the GS mini target. Thrust will barely change. In the latter case, thrust will gradually increase.
Let's say a day with strong wind gradient. GS mini will change abruptly, pitch will increase accordingly and thrust will be maintained or even increased it the airplane tends to overshoot the target due to inertia. In selected, thrust will be increased very sharply.
I would say that with managed speed thrust changes will be less than in selected speed.
Let's say a day with little wind gradient: GS mini will give a gradually diminishing speed until you reach VAPP. As compared with a constant selected speed at VAPP, there will be little difference. In the first case, thrust will change little, as the loss of energy due to less headwind will be roughly what the airplane needs to reduce speed and maintain the GS mini target. Thrust will barely change. In the latter case, thrust will gradually increase.
Let's say a day with strong wind gradient. GS mini will change abruptly, pitch will increase accordingly and thrust will be maintained or even increased it the airplane tends to overshoot the target due to inertia. In selected, thrust will be increased very sharply.
I would say that with managed speed thrust changes will be less than in selected speed.
