VegassBus

Thank you. . And I agree.

ColdWhiskey

Your technique may initially get the aircraft started down quicker (a function of how fast the auto thrust reduces engine power in the different a/p mode).

But with your technique, as the airspeed approaches 200, the auto thrust will add engine power to maintain both the 200 knots and the 1000 fpm descent (your FMA will change from 'idle' to 'speed' indicating that engine power has been added).

This addition of engine power will ultimately delay the amount of time to achieve the desired altitude loss. The use of 'open descent' will prevent the addition of any engine power until needed for level off (your FMA will remain in 'idle' during the descent).

With your V/S technique, how much engine power is added will be a function of what v/s is selected. Just realize that ANY addition of engine power will delay your descent.

VegassBus

Look, you could just spin the speed back, spin it up, increase/decrease V/S use the boards, use the gear etc.

My point is there are 10 different ways to do it in the Airbus and it took the really great CAs to teach me that. That's all

ColdWhiskey

I completely agree and also use this technique when using V/S mode. By doing so, you are essentially having to continue to change the selected v/s to achieve the desired airspeed (while not allowing the engines to come off idle). This is a bit of an increased workload. There is a function on the installed autopilot that does this for you automatically. It is called 'Open Desent'!!

ColdWhiskey

I agree!! You are the one that started this discussion by slamming the 'Old Crusties' that were doing it wrong and always high.

I agree that there are many different techniques that work, and I use many and enjoy learning more!

Frisco FO

Depends on how quickly ATC expects you to slow. At 1000 fpm I wouldn't expect the airplane to slow that quickly when clean. Open Descent generally descends at least 500 fpm and slows at the same time...which is exactly what ATC asked for. Yes, delaying compliance with an ATC speed adsignment by using V/S might help your descent rate, but I would rather just timely comply with clearances and use speed brakes when necessary.

northdakota

I think it is hilarious that all this "deep" talk is in the thread about Spirit pilots being low tier.

Lets talk about fuel calculations for diverting next.

Packrat

They had to design the airplane that way so low-time new hires paired with brand new ATPs wouldn't kill themselves and their passengers.

Name User

Yes I know. Third world plane. Only thing it doesn't do (yet) is drop the gear and flaps. I'm sure there is already functionality for it built in to the software.

ColdWhiskey

Yes, there are many different ways, and I am continually amazed when I see ones used that don't make the most sense to me.

One is how often I see someone descending using an autopilot mode that is resulting in engine power being added (V/S mode with a value selected that results in needed engine power, with the associated 'Speed' FMA), and at the same time using speed brakes.

This is no different than driving a car with one foot on the gas while wanting to slow down, and using the other foot to push the brake.

I'm not at all suggesting this is you, just noting that I see it often.