Airbus ALT*

[Newcomer2]

Hello!
Quick question: in my manual it says "do not select v/s or push to level off while in alt* "
Could someone explain why? All I can think of is that the aircraft may overshoot the altitude in that case (if so, why?), but is there another reason?
thanks!

[vilas]

ALT* is a capture phase with the set altitude. VS 0 or push to level is just that. It has nothing to do with altitude. If disturbed it will maintain VS0 at different altitude.

[Newcomer2]

Ok, but my manual doesn't mention V/S 0, just V/S. From what I understand you're not supposed to change the mode while in alt*. Let's say you're in OP climb, and just before reaching your target altitude you want to reduce the rate, you select V/S+500 without noticing you're in alt*. What can happen? Is there a risk of overshooting the altitude?

[Jesse Pinkman]

Newcomer2

V/S 0 is just another way of saying Push To Level. Pushing the V/S toggle demands V/S=0.

[Nightstop]

Pushing V/S Zero is an excellent method to reduce an excessive rate of climb or descent rapidly when you expect a TCAS RA will occur during ALT*, due traffic above or below. Once a reasonable rate is achieved, rearm ALT.

[tubby linton]

Alt* is what killed Nick Warner and others in an A330 as it had no speed protection.Pushing V/S=0 just shows a lack of SA of the traffic around you. Having flown an Airbus that had an impressive climb performance (A306) it was standard to minimise the climb rate well before the cleared altitude was approached.

[vilas]

Nightstop

No! During ALT* leave it alone it's too late. It's a capture phase where the rate of CLB or DES is flattening out. Even VS0 is not instant but gradual. You are likely to mess it up. When in a hurry people have played piano on the FCU. Pressing EXPED instead off ARM(ILS) then not knowing how to come out tried to press EXPED again but this time pressed ATHR causing THR LK, then trying to remove THR LK pressed ID on thrust levers driving thrust to CLB and busting speed and also causing GPWS terrain. Both seats were occupied by Training Captains.
TCAS does it's job well don't do anything last minute.

[Nightstop]

Both seats were occupied by Training Captains. That just goes to show that those who can’t do, teach 😉.

[vilas]

" those who have stopped learning have taken to teaching". Oscar Wild

[Nightstop]

No offence meant. This forum is not Bluecoat.

[FlightDetent]

No! During ALT* leave it alone it's too late.There is a chance. Actually, V/S = 0 is a way out and a decent choice. With 4000 fpm or alike it comes WAY too early and causes a whole lot of trouble.

Other methods, as you suggest, are actually futile and create even more confusion. V/S=0 is the way to go, unless you disconnect and remove FDs. In the heat of the moment, many forget the latter and you can guess the rest. For 1000-leveloff RA encounters without FDs, the statistics already spoke.

V/S = 0 is a trustworthy tool to get out of unwanted ALT*.

[tubby linton]

Do you remember the Armavia accident at Sochi in 2006 Flight Detent? The crew used the push to level off function and then engaged open climb within 30secs The accident report stated that by doing so the autopilot is allowed to use a more aggressive maximum value of 0.3g rather than the usual 0.15g.
The report is the only place I have ever seen that written but I have been more reticent to use this function after I was made aware of it.
https://www.bea.aero/docspa/2006/ek-9060502/pdf/ek-9060502.pdf

[Sergei.a320]

TorqueStripe

NO, you will capture Alt* as soon you have it in blue(magenta) on your FMA. If you overshot your FCU selected Altitude with use of V/S , Alt Blue(armed) will dissapear from FMA..

[Sergei.a320]

FlightDetent

I absolutely agree with you! It's worth nothing to push to lvl off, rather perform RA memory item ...
But if you are not sure where your VS 0 knob is, dont touch the "piano"...

[swh]

Newcomer2

If you want to reduce the V/S in ALT*, pull open climb. You will see a brief OP CLB then ALT*, with ALT blue, ie protected from a level bust. The second ALT* will be at a lower V/S as the climb to level off transition (ALT*) is recalculated.

[Mrmartinnico]

Unfortunately, it does not have to do with "over/under shooting the desired FCU alt", according to the FCOM:
"The ALT* and ALT CST* modes have internal V/S guidance that is a direct function of the difference between present altitude and the altitude target. The system switches automatically to ALT (altitude hold) when the altitude deviation becomes less than 20 ft." Taken from Autoflight, Flight Guidance, AP/FD Vertical Modes, Alt Acquire Mode.

Therefore, pushing V/S to level off, would command a level off (V/S 0) at the present altitude, instead of actually capturing the FCU ALT Target. On the other hand, selecting a V/S, eg: 100ft/min would only revert the vertical guidance to V/S + 100, which wouldn't capture the FCU altitude either.
Hope I'm not mistaken.

[FlightDetent]

tubby linton

(edited my original post)

I do very well, and the similarities with GF072 at Bahrain too. Also what geometric path of ALT* did to the A330 you rightfully mentioned. Definitely not an advocate V/S=0 for a makeshift go around, or doing 360 at low level instead of performing a proper one. Tons of Airbus presentations on that topic. Some tools at our disposal only need to be used when applicable and not when inappropriate.

True enough, the only other use case for V/S=0 I can think of is circle-to-land at 100 above MDA, really.

When gods of physics plays against us, with 4000 fpm climb rate you get ALT* at 2800 to go. Speed starts to drop, and you get TRAFFIC TRAFFIC against intruder 1k above the cleared level.

Push V/S=0, observe the nose drop with 0,3g unwinding VSI towards a reasonable value, dial +1500. Simples: one press and half-a-spin. Steady and predictable state results, neatly organized.


Reports of colleagues following the "outside of red arc" above the cleared level, towards the RA's target miss of 650 ft, are well known all over the world as a result of the full takeover option with their mind lagging behind.

The explanation behind OP CLB method sounds interesting, although my mind is playing tricks OP CLB is exactly what does not work.
Still feels unnatural at the first touch, OP CLB is something I'd normally associate with an unrestricted, more aggressive climb. VS=0 to interrupt the climb. The intuitiveness is opposite.

I did learn here about a trick where V/S=0 saves from further embarrassment if you got :E OP CLB instead of GS*, sounds interesting but for now it is an internet tip - so..

Any particular I painted myself into a corner stories about V/S=0 you're willing to share? Strictly anecdotal, of course. Do not get me wrong, I'd much prefer to heed the warning!

[vilas]

in my manual it says "do not select v/s or push to level off while in alt* "
​​​​​​when your manual specifically forbids something you don't do it because someone told you to. What happens if you did the answers are at variance. Discussion is OK but before actually doing it ask your company, may be Airbus through techrequest on Airbus world. I didn't suggest anything I just quoted an incident which was totally uncalled for but happened and was serious.

[pineteam]

Pushing V/S Zero is an excellent method to reduce an excessive rate of climb or descent rapidly when you expect a TCAS RA will occur during ALT*, due traffic above or below. Once a reasonable rate is achieved, rearm ALT.

I totally agree with you. This is common sense. Why would let have an RA if you can avoid it. This is not an escaping manoeuver just pilot technique to avoid triggering a RA. We had a case of TCAS RA both company traffic were on ALT*. I used vertical speed zero several times when I have excessive ROC/ROD especially on the NEO aircraft. It helps avoiding RA. It’s a mandatory occurence report here.

Also if you are doing NPA and you reach your FDP and you still on alt* You can not select FPA or VS. Pressing vertical speed zero allows this. Of course you can select an higher altitude then FPA. Both works.
I’m really curious to know why your company won’t allow to use vertical speed zero when in alt*.

[FlightDetent]

Though it's probably better formulated as a choice of technique to unlock ALT*. Not a decision between V/S=0 and nuisance RA, black-white.

Never thought of the FDP / ALT* combination as such but in retrospect, that's what indeed happened many times. Often the last moment both pilots and the FDM recordings will agree upon :) when debriefed.

[Check Airman]

So we’re in ALT* and want to change the vertical speed. There’s a very simple 2 step process I’ve encountered that works very well.

1. red button…..push
2. airplane……..fly

In ALT*, Autothrust is in SPEED mode. If it does something weird, push the other red button and go on to step 2.

[pineteam]

Arf Check Airman, don’t you know that most pilots will freak out if you do so? I don’t want my colleagues to have an heart attack on the sound of the AP tripping off. :}

[Check Airman]

Better a heart attack than a 21 gun salute.

[pineteam]

Joke aside, although as you know, I’m all in for hand flying, in that context, pressing vertical speed is easy peasy and so far I never had an RA using this technique. With those guys who never hand fly in line, if you ask them to disconnect there is a high risk they will over react and pull some serious G force and hurt cabin crews and/or passengers. Happened before...

[vilas]

it has happened many times because no matter how much you love hand flying you don't have any experience of it at cruise altitudes which are in RVSM. So if it's done in panic there can be trouble. The aircraft is very sensitive due to less damping. The correction in pitch and roll has to be much smaller scale and one has to remember all that in a hurry. It's much simpler to be conventional than be exceptional.

[pineteam]

Agree with you Vilas, at high altitude, I would only consider disconnecting if I really have to for that reason.
Even at low altitude I follow Airbus recommendation going from managed mode to selected mode first. I can’t even remember the last time I had to disconnect AP for path recovery. The few times I do is for example on A320 to get the full speed brake if I’m high on profile. :p

[vilas]

Airbus has an app called TCAP(TCAS alert prevention) to avoid nuisance TCAS RAs. When installed it automatically adjusts the altitude capture law to reduce ROD/ROC to avoid RA. Those interested can read an article about it in Airbus Safety First issue 13 January 2012.

[FullWings]

I find this kind of discussion fascinating, because here we have a bunch of highly experienced type-rated pilots, all with a slightly different interpretation of how/why a feature works and what to do if it isn’t performing as you want. This is not a dig at any of you, but an example of how the UI and documentation of the same on many aeroplanes is far from ideal. Even between different operators there seems to be alternative ways of dealing with the situation.

Over in Boeing World, there is a very similar thing with ALT (no *) but it serves for capture and hold, with quite a few quirks for the unwary. There are phases of flight where pressing the brown button (does the same as the AB red one) is preferable to improv jazz on the MCP which may or may not have the desired result...

[Fursty Ferret]

No! During ALT* leave it alone it's too late.

Going to respectfully disagree here.

Consider the situation where you climb into an increasing headwind at high level and experience a transient increase in airspeed, leading to a high rate of climb. If ALT* engages at this point you could be several thousand feet below your target altitude with the speed about to wash off. VS 0 is a perfectly reasonable mode to consider at this point to manage the energy situation. You can re-engage climb or select a sensible VS once the energy of the aircraft is doing what you want. Pulling for VS will just put you back into ALT*.

If you realise that this is going to happen a better way to manage the situation is to select the airspeed or Mach at something close to VMO or MMO, so that if the headwind washes off you can just go back to your original speed instead of experimenting with the low speed protections.

[pineteam]

Good point Fursty Ferret! I have seen Vertical speed going over 6000 feet quite fast during climb on A320 Neo. It’s actually normal to see vertical speed going around 4 or 5000’/min at 250kt on the Neos especially if you don’t have the option of the Alternate Climb. Those engines are amazing. :cool:

[vilas]

FurstyMy comment was for routine ALT* situation. If faced with unusual situation appropriate intervention may be in order. I have no problem with that. The second aspect is about something specifically not recommended in FCOM(poster's) being routinely brushed aside by line pilot. That I definite have problem with it. There what I suggested is a safe way to go about.

[FlightDetent]

:DSo we’re in ALT* and want to change the vertical speed. There’s a very simple 2 step process I’ve encountered that works very well.

1. red button…..push
2. airplane……..fly

In ALT*, Autothrust is in SPEED mode. If it does something weird, push the other red button and go on to step 2.Never heard of that option before, very grateful for you sharing the wisdom. :D

[tubby linton]

As we are discussing high climb and descents rates this is pertinent-
ICAO Annex 6 (4.4.10):
Aeroplane operating procedures for rates of climb and descent
Recommendation.— Unless otherwise specified in an air traffic control instruction, to avoid unnecessary airborne collision avoidance system (ACAS II) resolution advisories in aircraft at or approaching adjacent altitudes or flight levels, operators should specify procedures by which an aeroplane climbing or descending to an assigned altitude or flight level, especially with an autopilot engaged, may do so at a rate less than 8 m/sec or 1 500 ft/min (depending on the instrumentation available) throughout the last 300 m (1 000 ft) of climb or descent to the assigned level when the pilot is made aware of another aircraft at or approaching an adjacent altitude or flight level.

[vilas]

I forgot to mention that in some countries it's SOP to reduce vertical speed to 1000ft/mt within last 2000ft to level off. So the TA are avoided.
tubby
The VS recommendations differ within different authorities.

https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/896x381/screenshot_20210521_225209_2_ea6308713617198d15bef4a68a1e7c6 39cd05bba.png

[FlightDetent]

You can add Spain to the list, for manoeuvring in TMAs (simplified). At least that actually makes sense.

Once it's understood there's ONE technical specification and MULTIPLE regulatory restrictions, it becomes more apparent what a freak show this is.

Some entries in the table above are not even factual. Why is the FAA displayed as 500-1500? The threshold for traffic A flying level and B coming to 1000 above/below is 1700 fpm (35 sec above FL200) at the 1000 separation point - assuming the other traffic is there in the cross-hairs and without any gradual ALT capture of the one manoeuvring.

[FlightDetent]

Technical specifications, ACAS ver. 7.0

https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/405x251/snippet_tcas_thresholds_b0946c204bcda9adf2c6d8b85f34cda8f774 d71b.png
https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/640x311/snippet_tcas_manoeuvres_0b24bbea56843083d8300906c17fc4c7b310 cb76.png

[pineteam]

Thanks for sharing FlightDetent. Can you explain the right side of the table ? DMOD?
And maybe give another 2 examples with different altitudes please.
if at high altitude the TAU is higher therefore it should be easier to trigger a TA or RA if excessive ROC/ROD compare to low altitude?

[FlightDetent]

Ok, those tables are still somewhat simplified and I cannot vouch the values are truly identical with 7.1 or whatever is the latest. Secondly, I prefer not to hijack this ALT* V/S = 0 stuff, but as I already broke the first glass...

1) The right column shows the absolute (shortest) distance limit. Normally ACAS calculates the "closest point of approach" from the vector geometry and then warns at a pre-determined time threshold. That does not work at all for closely parallel trajectories, where CPA is minutes ahead but you'd be getting physically too close. DMOD (Distance-MODification) works in the lateral plane, imagine same-level traffic converging far ahead. Similar distance threshold exists in vertical plane (IIRC @ FL200+: TA=850 ft, RA=650 ft).

3) Agreed. Higher up the logic is more sensitive, asking for larger protective bubbles around respective traffic.

2) It's easy to calculate. FL160, one traffic at level, the other descending.

---
With 2000 to go before the cleared level, aiming to systematically avoid TA which is enough of a distraction.Limit V/S = 4000 fpm (rate) = 3000 ft (to-go distance + separation) / 45 sec (TAU TA) * 60 sec (per minute)
-->> Descending with 4000 fpm gets you TRAFFIC, TRAFFIC audio call 2000 ft before clearance limit.

Assuming pilots reduced the rate and continued with 2000 fpm instead of 4k,DIST = 1500 feet = 2000 fpm (rate) / 60 sec (per min) * 45 sec (TAU TA)
-->> TA "traffic, traffic" re-activates when 500 feet above the cleared level = 1500 feet from CPA (other traffic). Assuming the other plane is still there.
DIST = 1000 feet = 2000 fpm (rate) / 60 sec (per min) * 30 sec (TAU RA)
-->> a hard RA fires at 1000 before the CPA itself!. Exactly at your 1000 ft separation clearance limit = you need a level bust for it to sound - any sort of altitude capture will prevent it.---

Play around with the numbers, the final discovery is far from surprising. The original guidance provided from Airbus to its pilots (different from, or badly misquoted in table at post #35) is optimal.

when actually there is intruding traffic

if the V/S is excessive call "Check V/S" 2000 before target alt
do something so that
within the last 1000 ft before level off the V/S is not greater than 1500 fpm.

but do not change anything unless there was actual traffic.


Is it not overly conservative then? No, keep good room when the other plane is not level but manoeuvring against you (in line with ATC clearance).

[Uplinker]

.........in some countries it's SOP to reduce vertical speed to 1000ft/mt within last 2000ft to level off. So the TA are avoided.

It wasn't SOP with any of the airlines I flew for, but we all did it anyway - especially in busy TMAs. I still think it's odd that manufacturers never modified their software to perform this function automatically when TCAS came in and TA/RAs became a possibility.

Having to intervene just before the point of ALT capture every time is both a pain and a potential level bust.
But on Airbus; setting 1000'/min and pulling V/S before ALT* is surely much easier? ALT will still capture.

[vilas]

Uplinker

you are aware Airbus has made TCAP but it doesn't come as a standard equipment on A320. You got to perhaps pay for it.

[Uplinker]

Thanks vilas - I am aware now :ok:

We never had it, so I have not flown it.

[FlightDetent]

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.

[FlightDetent]

Uplinker

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

[vilas]

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.

[Denti]

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.

[Nick 1]

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 .

[vilas]

Nick 1
It's a very interesting incident, worth a discussion on PP.
https://livingsafelywithhumanerror.wordpress.com › ...
Descent below minimum permitted altitude, final report – Living ...

[Nick 1]

Thank you Vilas !

[pineteam]

FlightDetent, thank you very much for your detailed explanation on your post#39!!
Love this kind of information.

[vilas]

vilas

This is final report from ATSB

https://www.atsb.gov.au/publications/investigation_reports/2015/aair/ao-2015-048/

[Nick 1]

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.

[FlightDetent]

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.

[vilas]

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.

[Uplinker]

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?

[vilas]

He was also a training Captain.

[CaptainMongo]

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?

[Check Airman]

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.

[vilas]

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.

[FlightDetent]

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!

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. :E

[Check Airman]

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.

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.

[vilas]

We all have have likes and dislikes for some procedures, systems but it's safer to follow nevertheless because we are not aware of the complete thought process behind that. Also we may not know someone may have tried it differently with some unpleasant occurrences. Anyway learning never stops.

[Uplinker]

Both training Captains. WTF ?? I am sorry, but I hope they are both stripped pf their titles and returned to ranks..

........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. ”
I agree with Captain Mongo; The report comment that this guy's poor vision was not a factor is bull****. (We've all hit the wrong button, but not twice in a row) - coupled with him obviously not being able to focus on his PFD or the Engine N1/EPR gauges. This guy was operationally blind and should have been put out to grass

Nor could he even fly manually, FFS !! He was type rated, so he had studied the Airbus, passed exams about the Airbus controls, including auto-thrust, so he knew how it worked. Excuse my invective, but It pisses me off that people like this who can't fly and can't see get the plumb jobs, but mortals like us who do understand Airbus and can fly, don't get a look-in because of the seniority system and office politics. :mad:

@ Check Airman :ok: We've all been there. Every day is a learning day.

[Nick 1]

Here is my , flaps 2 selected speed close to loc capture pushed speed managed but , approach fase was not active !
Speed start increase fast , was like a slap in my face , what is doing ? Disconnect a/p call for flap 1 , disconnected a/thr call for flap zero level off
i passed the localizer , atc where shouting at us but we where new in the Airbus and fighting to trying to understand what was the problem , i still remember the 4/5 second of startle I experienced .
Later in bad i felt like an idiot thinking at the event , why I did not just pull for selected speed right after the push ......but you know Airbus is a different dog , sometimes you need to be bitten to learn .

[FlightDetent]

4 to 5 seconds startle is probably not something you can roll back in Airbus. Up to three perhaps, personal experience from both sides.

Side note, after LOC* the approach phase self-activates.

I was blessed with good instructors on the 737 who trained me properly that an illuminated MCP button means it can be de-actiavated. Whereas what mode actually is active
​​​​ needs to be checked by constant review of the FMA.

Never had an issue not noticing the managed speed jumping up, because the speed tape was the focus. Mixing up speed / heading / altitude selectors - different story, that takes longer than 3 seconds at times. :ouch:

For A/THR disconnect, the instinctive way is the easiest. Put the thrust where you need it to, and then click-off. I do understand the setup of the incident flight was far more complex than that.

In my overall opinion, full escape from the automation trap needs more hands-on training than is being done. I am a great fan of slowly decreasing the level of automation instead of an instinctive and mostly premature all-disconnect. Yet when it needs to be done it needs to be done properly. All off, set pitch and power FDs off! Quickly and decisively.

Very often some sort of feature is left engaged by error of either ommision or bright idea. Which backfires by making the situatuon hard to read, process and prioritise.

My last flop was as simple as keeping the FDs on when doing a 90 deg hard avoidance turn having just disconnected the AP for urgency. Just to wait for the PM to select a proper heading target while I banked towards the safe side... error of a bright idea. 😟 The pitch bar with ALT* and A/THR in CLB did the killing.

[vilas]

Actually I was incorrect about the details of the incident. It was even more totally uncalled for. The capt pressed EXPED Instead of APP by mistake passing 3600ft to target altitude of 3000ft. He didn't have to cancel it because ALT* engaged immediately and aircraft had levelled off. End of story. But he didn't check the FMA and tried to push EXPED again to cancel it and again by mistake pressed ATHR causing ATHR to go in THR LK. So? just re engage by pressing ATHR again. Again would have been end of story. Unless he went for AP switch this time. But since he had enough of the FCU, for no reason whatsoever went for the click, click. That was actually the blunder which could have killed everybody.

[FredFlintstone]

As a newbie to Airbus myself, something said to me in the sim still rings true.

“An inexperienced Airbus pilot will say what’s it doing now, whilst an experienced Airbus pilot will say it does that sometimes”

I miss my 747-400!

[vilas]

I also switched to A320 after being a training Captain on B747 classic. This incident is due to ignorance of the pilot, nothing to do with the aircraft. When you fly a new machine you have to know it well to be truly comfortable not the comfort that comes out of ignorance. You read my earlier post. This fellow commits blunders after blunders without any requirement and you bring some strange comment perhaps from guy who also knew very little. China Airline pilot in a 747 dealing with a single engine failure did a complete barol role. So what wise crack would you have for that?

[pineteam]

Side note, after LOC* the approach phase self-activates.

My last flop was as simple as keeping the FDs on when doing a 90 deg hard avoidance turn having just disconnected the AP for urgency. Just to wait for the PM to select a proper heading target while I banked towards the safe side... error of a bright idea. 😟 The pitch bar with ALT* and A/THR in CLB did the killing.

Did not know it will self activate when in Loc*! Thank you for that.
I don’t understand what went wrong in your situation described above.
you disconnect AP and disregard FDs and start banking. if the FMA was on ALT* The A/THR must have been in SPEED mode and not in CLB thrust anymore??

[vilas]

Side note, after LOC* the approach phase self-activates.
LOC* doesn't activate APP phase but the overflying the D in NAV mode does it and LOC* is also taken as NAV. If flight plan is not sequenced LOC will be captured without activation of approach phase.

[CaptainMongo]

… This incident is due to ignorance of the pilot, nothing to do with the aircraft. When you fly a new machine you have to know it well to be truly comfortable not the comfort that comes out of ignorance. …


Very true words Vilas. I describe it as a “curious lack of curiosity.”

Some pilots, when they note the airplane didn’t do something they expected it to do, just shrug their shoulders and move along. Most pilots want to find out why it did something they didn’t expect.

[FlightDetent]

LOC* doesn't activate APP phase but the overflying the D in NAV mode does it and LOC* is also taken as NAV. If flight plan is not sequenced LOC will be captured without activation of approach phase.That sounds like the proper explanation.

Assuming vectors, i.e. HDG lateral mode: Clear the unnecessary waypoints with or without using the DCT-TO (rad-in), but continue on HDG. Joining LOC* the FMGS starts looking for the DECEL - again - (already past) and APCH phase gets activated.

When I first heard about it, it did not sound quite right. Background memories of LOC* definitely NOT saving me from no APCH phase. :E

[FlightDetent]

what went wrong in your situation described above.
you disconnect AP and disregard FDs and start banking. if the FMA was on ALT* The A/THR must have been in SPEED mode and not in CLB thrust anymore??You're right, I mixed up the description. But it was not the automation failing (it never does) that went wrong, the human side got behind the airplane and missed things. I'm convinced less automation then might have been beneficial. No need to monitor it, no need to follow it, no need to announce it, no need to command adjustments and clarify them with PM, etc. ... you have more time to watch the bank properly...

Also I learned that night "left" and "right" can actually be indecipherable. Always thought that sometimes they come strangely close by the sound of it, but never believed 3 focused people already aware of a misunderstanding could not figure it out.

[Speedwinner]

What happens if we takeoff with 100ft in the altitude window. What will haben with the athr and the modes of the autopilot?FD?

[enzino]

I guess it stays in Take Off Phase until ACC ALT. Anyway A/THR is armed in FLX or TOGA and it engages when thrust levers are moved to the CLB detent. Who does that at 100 ft?

[sonicbum]

What happens if we takeoff with 100ft in the altitude window.

Should be:

1) A level bust
2) An ASR
3) Tea and biscuits with safety

[CVividasku]

If I believe the trainer simulator that I just tried, if you do that, you will remain in SRS forever.
The airplane will not accelerate nor will it let you pull speed and choose another one, except if you engage another vertical mode.
Apparently, if you set the altimeter target above your altitude too late, that is after the acceleration altitude, the clb alt blue modes do not engage, you remain in SRS but in one case I simulated I kept SRS alt blue. So when the airplane reached the level I had chosen, the airplane levelled off from SRS to ALT*.

It sounds realistic but that may just be the sim.

[vilas]

Should be:

1) A level bust
2) An ASR
3) Tea and biscuits with safety
SRS once engaged on takeoff only disengages at acceleration altitude unless you engage another vertical mode. It doesn't seem to react to FCU altitude if below acceleration altitude unless you pull climb or VS.

[Speedwinner]

Ok so the Airbus will disregard the 100 ft and do the normal acceleration after takeoff with managed climb without alt target?

[pineteam]

Ok so the Airbus will disregard the 100 ft and do the normal acceleration after takeoff with managed climb without alt target?

Yes. ALT* can not engage below 400 feet RA. I believe you will stay in SRS mode until acceleration altitude then Vertical speed mode until pilot action.

[sonicbum]

SRS once engaged on takeoff only disengages at acceleration altitude unless you engage another vertical mode. It doesn't seem to react to FCU altitude if below acceleration altitude unless you pull climb or VS.

Correct.
I believe You quoted the wrong post though 😅