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A320 OP CLB behaviour

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A320 OP CLB behaviour

Old 2nd Oct 2019, 17:09
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Deleting restrictions to be able to use managed climb over open climb is the gold medal of putting SOP over common sense.
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Old 2nd Oct 2019, 17:15
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Originally Posted by hans brinker
Deleting restrictions to be able to use managed climb over open climb is the gold medal of putting SOP over common sense.
Hahaha! Could not agree more! A bit like guys going heads down in the MCDU to delete the 250kt speed constraint below FL100 instead of selecting the speed on the FCU... smh
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Old 2nd Oct 2019, 20:49
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Originally Posted by hans brinker
Deleting restrictions to be able to use managed climb over open climb is the gold medal of putting SOP over common sense.
Absolutely. I'm not entirely sure why we do it that way, I haven't been here long and this is just what they're doing. As far as I know there is no prohibition on using open climb instead.
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Old 2nd Oct 2019, 22:38
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Thumbs up

Originally Posted by hans brinker
Deleting restrictions to be able to use managed climb over open climb is the gold medal of putting SOP over common sense.
HAHAHAHA

This made my day! Well said, sir.

We need a "like" button on this forum.
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Old 3rd Oct 2019, 03:43
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NO doubt when possible managed modes should be used but when unrestricted climb has been given use of OP CLB is what it is for. To stay in CLB by deleting waypoint is creating laborious head down work because you have to ensure you are not deleting a wrong constraint. Climb and descent have a difference. CLB and OP CLB are same without constraints they don't track any vertical path but in descent even without constraints DES follows a path calculated all the way to 1000ft on approach. OP DES is used only when you want max rate of descent with idle thrust. If you deleted constraints in descent FMS will rework the path but nothing of that sort happens in climb.
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Old 3rd Oct 2019, 13:23
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Originally Posted by krismiler
The autothrust is quite slow to react to changes, it probably targeted the lower speed first by reducing power and then realised you wanted to climb so it increased power. It's a 1980s design and can't keep up with even a modern smartphone. You would have been better off waiting until the aircraft was properly established in the climb before winding the speed back or managing it.
I have the impression that the older A320s had a better A/THR response and spool up time. Did something change in the FADEC software? Both CFM and IAE engines at the previous companies that I’ve worked for spooled up faster and had better A/THR response than the current (new but still CEO) IAE engines that I’m flying now.
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Old 3rd Oct 2019, 21:21
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A previous operator had a number of aircraft that would exhibit this behaviour. Traditionally in open climb reducing speed would produce a pitch response to meet the target but one software fit would trigger the auto thrust to reduce thrust instead. I remember the first time I saw it there were a few expletives and why is it doing that. The software changed a few months later back to what I had been used to.
Open climb should be a speed based pitch mode with auto thrust commanding climb thrust, not the autothrust commanding speed
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Old 4th Oct 2019, 03:11
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Open climb should be a speed based pitch mode with auto thrust commanding climb thrust, not the autothrust commanding speed
Off course it is but the way it is initiated is through VS, speed in the background. The pitch up occurs to give you a pre set VS and thrust comes up to maintain speed till 95% N1 and then continues to THR CLB and speed maintanence is switched to pitch. Had it not been so and thrust would have moved to climb then to control speed the pitch up may have been too harsh. It's Airbus design I don't how Boeing does it.

Last edited by vilas; 4th Oct 2019 at 03:31.
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