A320 climb question
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A320 climb question
Hello,
If, even after climbing at best rate (turbulent speed), ATC says "Expedite Climb", is it advisable to climb at best angle (GD), or just tell them that it's the best you can do.
Thanks
If, even after climbing at best rate (turbulent speed), ATC says "Expedite Climb", is it advisable to climb at best angle (GD), or just tell them that it's the best you can do.
Thanks
It really depends on the situation.
If ATC is hoping to climb you over conflicting traffic or terrain, or before reaching a waypoint - at some specific place, then GD (best angle or gradient speed = Vx) will get you higher in the minimum distance (because you're flying slower = more time available to climb before reaching the crossing point).
To reach the new altitude in the minimum time (but not the minimum distance) then turbulence speed (generally) is your best climb rate (Vy).
If ATC is hoping to climb you over conflicting traffic or terrain, or before reaching a waypoint - at some specific place, then GD (best angle or gradient speed = Vx) will get you higher in the minimum distance (because you're flying slower = more time available to climb before reaching the crossing point).
To reach the new altitude in the minimum time (but not the minimum distance) then turbulence speed (generally) is your best climb rate (Vy).
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Also consider that if the best rate is only needed for the next few thousand feet, reducing speed will allow for a much larger rate of climb. Of course this is only temporary, but perhaps all that is needed to clear traffic.
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ATC response!
I hope you are given a level to expedite through as it is being taught more and more - obviously if you only have a few 1000ft you could give us more than expediting for 10000ft. If you are close to maximum rate already, tell us that, and say you can give us 500ft maximum etc more for only 2000ft if that is the case, and that you will fall to only 500ft/min if you do thereafter. We are really in your hands for this, and if you cannot give us much more, there should always be a second plan by the controller keeping all safe. Levelling off is a good compromise.....
I hope you are given a level to expedite through as it is being taught more and more - obviously if you only have a few 1000ft you could give us more than expediting for 10000ft. If you are close to maximum rate already, tell us that, and say you can give us 500ft maximum etc more for only 2000ft if that is the case, and that you will fall to only 500ft/min if you do thereafter. We are really in your hands for this, and if you cannot give us much more, there should always be a second plan by the controller keeping all safe. Levelling off is a good compromise.....
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If, even after climbing at best rate (turbulent speed), ATC says "Expedite Climb", is it advisable to climb at best angle (GD), or just tell them that it's the best you can do.
Well said Zonoma; communication: To Matthew; it's team work. I agree that a request to 'expedite' is imprecise and open to guesswork. Just ask ATC what they want. They have a plan in mind, but you don't know what it is. Their meaning of expedite might be different to yours. They'll want to have you crossing a level by such a point or time. They may not have run a computation at your current ROC. They just want to ensure that you'll achieve a level within their plan, hence expedite. Find out what the goal is and then advise if you can achieve it. Also have an answer as to what you can achieve at the critical point/time then ATC can work around that. They can vector you, issue a re-clearance level, or shift the other traffic. It may be the call is to achieve a standard silent handover level to another sector. If you can't make it ATC can liaise with that sector and find out what is acceptable.
Rather than second guess ATC use good CRM and ask a question to help the team work with effective teamwork.
Well said Zonoma; communication: To Matthew; it's team work. I agree that a request to 'expedite' is imprecise and open to guesswork. Just ask ATC what they want. They have a plan in mind, but you don't know what it is. Their meaning of expedite might be different to yours. They'll want to have you crossing a level by such a point or time. They may not have run a computation at your current ROC. They just want to ensure that you'll achieve a level within their plan, hence expedite. Find out what the goal is and then advise if you can achieve it. Also have an answer as to what you can achieve at the critical point/time then ATC can work around that. They can vector you, issue a re-clearance level, or shift the other traffic. It may be the call is to achieve a standard silent handover level to another sector. If you can't make it ATC can liaise with that sector and find out what is acceptable.
Rather than second guess ATC use good CRM and ask a question to help the team work with effective teamwork.
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matthewgamm
You should know that use of Green Dot speed to expedite climb is only recommended below FL250. Above FL250 it is turbulence speed. Since you are already at turbulence speed you are not in a position to oblige the ATC. You have on your MCDU PERF page the ETA to the cleared level in time as well as the distance. So just say "Unable" and give that(ETAs) to ATC and let them do their job.
You should know that use of Green Dot speed to expedite climb is only recommended below FL250. Above FL250 it is turbulence speed. Since you are already at turbulence speed you are not in a position to oblige the ATC. You have on your MCDU PERF page the ETA to the cleared level in time as well as the distance. So just say "Unable" and give that(ETAs) to ATC and let them do their job.
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Hopefully you will have an altitude to expedite through. If you're on lower levels (below 250) and the level ATC wants you through quickly is not above that level you could use expedite climb. Be aware of how high is the altitude ATC wants you through vs the altitude you're currently crossing. There's no point in climbing at green dot speed for a couple thousand feet, just reduce your speed accordingly. If you're at higher FL's watch your speed don't get too slow, keep a safe margin from VLS, especially if in or expecting turbulence. In this case, do the best you can keeping in mind your speed and advise ATC of your rate of climb so they know what your airplane is capable of and they can plan accordingly. As always, in this last case, it's best to err on the safe side regarding your ROC. Don't get over optimistic
