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Airbus ALT*

Old 22nd May 2021, 09:54
  #41 (permalink)  
 
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Thanks vilas - I am aware now

We never had it, so I have not flown it.
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Old 22nd May 2021, 09:54
  #42 (permalink)  

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Which is nice but reactive. More traffic friendly altitude capture would be better, preemptive.

The experience is mirrored that when the VS actually is excessive the ALT* latches way too early, around the 2000 feet distance even. Why not then, yes, have the ALT* perform the smoothing.

@Uplinker PANS-OPS strongly advises against messing with the AP modes for every single level off.
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Old 22nd May 2021, 09:56
  #43 (permalink)  

Only half a speed-brake
 
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Uplinker

We have it on some but are not allowed to use it. And the smart thing keeps reactivating FDs all the time. 🤦‍♂️

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Old 22nd May 2021, 15:49
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When the whole fleet is not equipped it is safer not allow it's use than expect pilots to remember every aircraft. Same is the case with AP/FD TCAS. Airlines forbid it's use unless the whole fleet is modified with it.
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Old 22nd May 2021, 16:48
  #45 (permalink)  
 
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Different things there in my view. AP/FD TCAS is something that announces its existence very clearly and early on, with a TA you get TCAS blue, if its there, let the system do its job, if its not use the "old" procedure. No need to wait for a whole fleet to be modified, especially as retrofitting is so expensive that it is basically economically unviable to do so.
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Old 22nd May 2021, 16:51
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Hi Vilas , there is any final report of the occurrence where the two pilots where playing the piano on FCU ? Should be an interesting read .
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Old 22nd May 2021, 17:46
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It's a very interesting incident, worth a discussion on PP.
https://livingsafelywithhumanerror.wordpress.com › ...
Descent below minimum permitted altitude, final report – Living ...
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Old 22nd May 2021, 22:40
  #48 (permalink)  
 
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Thank you Vilas !
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Old 23rd May 2021, 03:23
  #49 (permalink)  
 
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FlightDetent, thank you very much for your detailed explanation on your post#39!!
Love this kind of information.
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Old 23rd May 2021, 08:16
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vilas

This is final report from ATSB

https://www.atsb.gov.au/publications...r/ao-2015-048/
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Old 23rd May 2021, 10:03
  #51 (permalink)  
 
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Thanks Vilas .Very dangerous on every airplane pushing buttons without know what they will do , but specially on the Bus , one wrong selection and you can generate a sequence of mistake one after the other.
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Old 23rd May 2021, 10:20
  #52 (permalink)  

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Originally Posted by AAIB
The PF responded to the rapidly increasing thrust by applying pitch-down inputs on the sidestick (point 6). The PF did not recall applying pitch-down input during post occurrence interviews, but did recall thinking that the aircraft was pitching up.
Yes. Also watch out for speedtape confusion with flaps out. The red barber pole descends from above towards the target. Historically pilots are trained to fly the needle, not the scale behind it.

It can be reproduced in the sim.

But it is a scary read, thank you vilas. Namely the crew's recollection of NOT hearing any terrain warning.

Last edited by FlightDetent; 23rd May 2021 at 12:22.
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Old 23rd May 2021, 11:08
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The Capt while passing through 4700ft to 3000ftaccidentally engaged EXPED and he wanted to cancel it. The irony is, first he didn't have to because ALT* would have engaged in perhaps 30secs. automatically cancelling it. OK he wanted to cancel it by pushing EXPED again but that is the only action that wasn't going to do it. Any other action on FCU(except HDG) pull speed/pull or push ALT/push or pull VS would have done it but he by mistake he went for ATHR. Then ID button and hell brakes loose. ATSB report is an exercise in being politically correct. The only reason for the incident is insufficient or half knowledge of EXPED function. Had he known how to come out, it wouldn't have happened. But ATSB runs the whole gamut of human factors, ergonomics but not the real cause. The important lesson always read before pulling or pushing.[/QUOTE]
Actually I was wrong about the details of the incidence. It was even more totally uncalled for. The Capt pressed EXPED descending to 3000ft passing 3600ft. AP was on and ALT* happened immediately and aircraft levelled off. So all was fine. The Pilot didn't seem to have noticed ALT on the FMA and pressed EXPED to cancel it which was wrong for three reasons, first it's not designed that way, second EXPED had already changed to ALT, third there was no target altitude to either activate EXPED. OK! He made another mistake and pressed ATHR instead. But that wouldn't change anything just reengage on the FCU. But now he makes the real mistake of unnecessarily clicking off AP and ATHR. This Click, click could have taken their life.

Last edited by vilas; 25th May 2021 at 12:56.
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Old 24th May 2021, 10:33
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I have just read this ATSB report - good grief. What the hell were they playing at?

I would suggest the following problems not mentioned by the report:

It would seem to me that PF's eyesight was below regulation if he could not see clearly enough and pressed EXPED instead of APPR, and then a few moments later pressed A/THR by mistake. And/or his hand-eye coordination was very poor.

Secondly, PF seemed not to be looking at, nor understanding his PFD, because he pitched forward in response to forward acceleration, believing he was pitching up - a classic rookie pilot mistake. Or maybe poor eyesight again? Reference is made to flight in cloud and lack of an external horizon, and we see this cited fairly often in accidents. We are supposed to be IFR pilots. We rely on and (should) fly by visual reference to our PFD.

Then PF was obviously confused by the auto-thrust lever logic.

It seems to me that PF was not very au fait with the Airbus, and/or was tired or confused as well as having poor eyesight and poor scan. He seemed to be out of his depth when things departed from normal, and could not seem to recover. How was he a Captain?

The cockpit lighting was very low. I have flown with people who do this and don't understand them. Again, we should be flying by our instruments, so having them too dimly lit is dangerous.

Two Captains were flying together and the PM Captain found it hard to speak up or take control - Why? Because of the loss of face? How was the PM a Captain?
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Old 24th May 2021, 11:55
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He was also a training Captain.
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Old 24th May 2021, 14:26
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Both PF and PM were training Captains.

WRT vision:

”The PF held a current Class 1 medical certificate, and as a condition of that certificate was required to wear distance vision correction and have available reading correction. These vision requirements were determined to have not influenced the occurrence. ”

Having reading correction available while being required to wear distance vision correction is nonsense. What does a pilot do with those restrictions on a medical? Switch glasses every time you look inside the cockpit?
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Old 24th May 2021, 15:45
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I suppose the only thing the PF did right was to disconnect the AP when the aircraft wasn’t doing what he wanted. But then for whatever reason, (eyesight, lack of proficiency?) things continued downhill.

I also fault Airbus for the thrust lever design. Had they been “conventional”, the whole bit with thrust lock then climb wouldn’t have been a factor.
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Old 24th May 2021, 17:26
  #58 (permalink)  
 
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Aircraft wasn't doing what he wanted? That's a joke. It exactly did what he asked. If he didn't know how to ask then it's his fault. It's mentioned in his earlier checks that he has a habit to select something in a hurry. Click, click doesn't work unless you know what is happening and what you want to do. A/C is diving, thrust has hit climb, speed is increasing, you don't know what to do with AP. OK slam the thrust closed, knock the AP off and level off.
I also fault Airbus for the thrust lever design. Had they been “conventional”, the whole bit with thrust lock then climb wouldn’t have been a factor.
But then it wouldn't be called Airbus but perhaps B MAX. Boeing is conventional but still they crashed it in SFO, nobody had any idea what conventional ATHR was doing, another in Dubai go around they had no idea what they needed to do for touch down GA. NTSB, FAA asked Boeing to have look at thrust hold. They will keep looking but aren't going to do anything. Pilot flying has to learn and remember.
Look Airbus is Airbus it's easy but definitely different. Guy who transitions on to it has to learn about it. What ATHR does or doesn't is not a secret it's there in the manual, it's taught. What about the PM why didn't he do something? Perhaps he also had no idea. This is the problem with CRM. Unless copilot is well trained he is not going to overrule the more experienced captain. There was only one problem the capt didn't know how to cancel EXPED, period. Had he pulled any FCU button the flight would have ended without any excitement.

Last edited by vilas; 24th May 2021 at 17:38.
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Old 24th May 2021, 17:50
  #59 (permalink)  

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Attempting to stop it from doing something unsuitable does not cut it.

The key point here is you tell the aircraft to do what you need it to. But that you must know yourself in the first place.

Pitch 2,5°
N1 = 55%

Thrust levers being in the cargo compartment, controlled by Bluetooth and aft galley coffee maker pressure for all I know, no difference!

Originally Posted by vilas
What ATHR does or doesn't is not a secret it's there in the manual on the instrument panel, centre DU.
Fixed that for you.
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Old 25th May 2021, 04:42
  #60 (permalink)  
 
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Originally Posted by vilas View Post
Aircraft wasn't doing what he wanted? That's a joke. It exactly did what he asked. If he didn't know how to ask then it's his fault. It's mentioned in his earlier checks that he has a habit to select something in a hurry. Click, click doesn't work unless you know what is happening and what you want to do. A/C is diving, thrust has hit climb, speed is increasing, you don't know what to do with AP. OK slam the thrust closed, knock the AP off and level off.
Sorry. I should've been more clear. It was doing exactly as he asked it to do- just not what he intended it to do. I agree that the initial problem was entirely his fault (pressing EXPD instead of APPR). We've all pushed the wrong button at some point. He had an incident because of what happened after the mistake was realised.

Originally Posted by vilas View Post
But then it wouldn't be called Airbus but perhaps B MAX. Boeing is conventional but still they crashed it in SFO, nobody had any idea what conventional ATHR was doing, another in Dubai go around they had no idea what they needed to do for touch down GA. NTSB, FAA asked Boeing to have look at thrust hold. They will keep looking but aren't going to do anything. Pilot flying has to learn and remember.
Look Airbus is Airbus it's easy but definitely different. Guy who transitions on to it has to learn about it. What ATHR does or doesn't is not a secret it's there in the manual, it's taught. What about the PM why didn't he do something? Perhaps he also had no idea. This is the problem with CRM. Unless copilot is well trained he is not going to overrule the more experienced captain. There was only one problem the capt didn't know how to cancel EXPED, period. Had he pulled any FCU button the flight would have ended without any excitement.
I stand by my comment. No design is perfect. The fact is that disconnecting autothrust is usually a two step process. Boeing, Douglas etc have a system that isn't that broken. Airbus decided to fix it, and it sometimes leads to unnecessary confusion.

As an aside vilas, if you recall, I've long thought reading FMAs aloud was a silly idea- to put it mildly. I was wrong. I've had a come-to-Jesus moment that involved some paperwork. Lesson learned.
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