Flight envelope protection event involving an Airbus A320
This discussions might be invaluable - but only if there is something sensible said.
Comments such as "SA is the biggie here" and the "Superman philosophy" hardly contribute to a rational discussion about this.
I certainly was not there and do not work for this company, as are probably most of the posters, but the hindsight committee on this forum is clearly alive and well.
Comments such as "SA is the biggie here" and the "Superman philosophy" hardly contribute to a rational discussion about this.
I certainly was not there and do not work for this company, as are probably most of the posters, but the hindsight committee on this forum is clearly alive and well.
As a bus pilot I'm curious how the 737 handles an over speed with the A/P engaged?
It seems the me the Airbus logic of only providing increased elevator authority in 'Expedite Descent' mode to prevent an overspeed should also be provided anytime the speed is close to the barberpole in any descent mode, (maybe even climb, altitude capture logic etc permitting). The Airbus does not have an amber caution range for high speed like the 737, (again I do not know what the amber range on the 737 represents or it's effect on the AFCS, if any) rather, with the Airbus you are in the green or you are in the red. Over speed too much and only then will the A/P react (prior to this the A/T should have reduced, or the pilot intervened) In my view the Airbus managed modes are full of threats for newbies.
It seems the me the Airbus logic of only providing increased elevator authority in 'Expedite Descent' mode to prevent an overspeed should also be provided anytime the speed is close to the barberpole in any descent mode, (maybe even climb, altitude capture logic etc permitting). The Airbus does not have an amber caution range for high speed like the 737, (again I do not know what the amber range on the 737 represents or it's effect on the AFCS, if any) rather, with the Airbus you are in the green or you are in the red. Over speed too much and only then will the A/P react (prior to this the A/T should have reduced, or the pilot intervened) In my view the Airbus managed modes are full of threats for newbies.
The event was clearly the result of Mishandling of the primary controls during a normal encounter with changing wind conditions during climb.
The aircraft raw data in the Report shows the following.
The FO extended the speedbrakes and LEFT THEM EXTENDED extended for nearly 60 seconds until they were auto-retracted by the activation of Alpha Floor. The speedbrake lever eventually was selected to the retract position by the Captain on his return.
The FO selected the Thrust Levers to near idle (on the second occasion) just as the aircraft was entering (high) Alpha Protection. He did NOT select the Thrust Levers to TOGA in accordance with the FCOM procedure when Alpha Floor was activated. The Capt selected the throttles to Climb on his return.
The ATSB Report on the incident is woefully inadequate in addressing the primary and secondary causative issues and indicates a lack of understanding and thorough analysis.
There are very clear inadequate training issues to be addressed and they were not identified by the Report.
Good airmanship dictates that when using the speedbrakes it is advisable to always leave one's hand on the lever until they are retracted (except momentarily for other control selections) so as not to forget they are extended.
At high altitudes especially, speedbrakes should be the primary method used to prevent overspeed when excessive speed trends occur. Thrust reduction is not effective in the short term to stop an excessive speed trend close to Vmo and the engines take forever to spool up again from idle.
In case of actual overspeed, FCOM procedures should of course be followed... which normally includes Thrust Levers to Idle and Speedbrakes extend.
The FO exhibited classic symptoms of sensory overload...something that proper simulator training in high altidude speed excursions would easily address...
Alas I fear the message has being lost in the smoke and mirrors of the Auto Flight Modes understanding or non-understanding, usage or non-usage arguments.
The aircraft raw data in the Report shows the following.
The FO extended the speedbrakes and LEFT THEM EXTENDED extended for nearly 60 seconds until they were auto-retracted by the activation of Alpha Floor. The speedbrake lever eventually was selected to the retract position by the Captain on his return.
The FO selected the Thrust Levers to near idle (on the second occasion) just as the aircraft was entering (high) Alpha Protection. He did NOT select the Thrust Levers to TOGA in accordance with the FCOM procedure when Alpha Floor was activated. The Capt selected the throttles to Climb on his return.
The ATSB Report on the incident is woefully inadequate in addressing the primary and secondary causative issues and indicates a lack of understanding and thorough analysis.
There are very clear inadequate training issues to be addressed and they were not identified by the Report.
Good airmanship dictates that when using the speedbrakes it is advisable to always leave one's hand on the lever until they are retracted (except momentarily for other control selections) so as not to forget they are extended.
At high altitudes especially, speedbrakes should be the primary method used to prevent overspeed when excessive speed trends occur. Thrust reduction is not effective in the short term to stop an excessive speed trend close to Vmo and the engines take forever to spool up again from idle.
In case of actual overspeed, FCOM procedures should of course be followed... which normally includes Thrust Levers to Idle and Speedbrakes extend.
The FO exhibited classic symptoms of sensory overload...something that proper simulator training in high altidude speed excursions would easily address...
Alas I fear the message has being lost in the smoke and mirrors of the Auto Flight Modes understanding or non-understanding, usage or non-usage arguments.
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The FO exhibited classic symptoms of sensory overload...something that proper simulator training in high altidude speed excursions would easily address...
PG
Originally Posted by Ned Gerblansky
Unless the crew is supplemented, at some stage in a long sector a pilot will leave to go to the toilet. The pilot remaining will then be single pilot, obviously. To those who say that 2 pilots should be on the flight deck for a level change, I question what happens when ATS say "Due crossing traffic climb NOW to F360"? Do you reply "Unable due captain having a leak", and then accept the 90 degree turn? What does the captain think when they feel the aircraft change heading in that scenario? Personally I would cease "splashing the boots" and get back into the cockpit and ask "What were you thinking?!!"
Nunc est bibendum
Due crossing traffic climb NOW to F360
Let's be honest though, how often does this sort of clearance arise? I've had less than a handful in the last 19 years. It's not clear that this was the circumstances in this case.
Which brings me back to point 1. An understanding of 'least risk'. As an ex cadet, two years in the back seat of a 744 at least gave me some pretty good exposure to the demonstration of this before I then did F/O training.
We all make mistakes (as I did making a climb in much more benign circumstances) and it's important to learn from them in terms of the specifics. However unless we go back a step from the physical errors made and loom at the cultural and other non technical aspects of these sorts of events (which it doesn't appear the ATSB report delves into) then we're missing half of the lesson and to my mind probably the most critical part- the part that stops these things or similar from happening in the first instance.
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As an ex cadet, two years in the back seat of a 744 at least gave me some pretty good exposure to the demonstration of this before I then did F/O training.
The guy in the left seat is finding himself single pilot on many occasions when the flight goes "off script". I think the Australian public deserves better than that...but unfortunately this program is more about industrial agendas than pilot shortages.
I hear this issue (cadet overload) is a regular occurrence and was a causal factor in an incident with a flight departing YBSU recently without any V Speeds in the box...
PG
FlexibleResponse
Thats a wind up right?? You wouldn't wanna do that in a heavy 321 or 320 for that matter.
The speed brakes retract at a slower rate at high speeds which makes getting rid of them even tricker if the whole thing is botched up.
Since this wee mishap, the SOP has changed to speed brakes 'as required'
And no need for the cadet bashing, it wasn't a cadet.
At high altitudes especially, speedbrakes should be the primary method used to prevent overspeed when excessive speed trends occur.
The speed brakes retract at a slower rate at high speeds which makes getting rid of them even tricker if the whole thing is botched up.
Since this wee mishap, the SOP has changed to speed brakes 'as required'
And no need for the cadet bashing, it wasn't a cadet.
I wanna get in the Sim with Superman, he'll know what to do
Pretty much everything we do day-to-day is covered somewhere in the FCTM & other Doc's but sometimes there's nothing like experience & common sense to deal with an odd situation, both these traits are of a variable nature.
The Sim is the best place to practice this stuff with a grey bearded old salt of a Capt, not out on the line.
Wmk2
Pretty much everything we do day-to-day is covered somewhere in the FCTM & other Doc's but sometimes there's nothing like experience & common sense to deal with an odd situation, both these traits are of a variable nature.
The Sim is the best place to practice this stuff with a grey bearded old salt of a Capt, not out on the line.
Wmk2
Originally Posted by GA Driver
Thats a wind up right?? You wouldn't wanna do that in a heavy 321 or 320 for that matter.
The speed brakes retract at a slower rate at high speeds which makes getting rid of them even tricker if the whole thing is botched up.
Since this wee mishap, the SOP has changed to speed brakes 'as required'
The speed brakes retract at a slower rate at high speeds which makes getting rid of them even tricker if the whole thing is botched up.
Since this wee mishap, the SOP has changed to speed brakes 'as required'
My airbus SOP says keep the AP ON, Speedbrake.
Of course in a climb with the AT targeting a CLB N1 target, not speed, something must be done about the THR; ALT would put it into SPD mode and reduce it nicely, speedbrake as required.
Nunc est bibendum
And no need for the cadet bashing, it wasn't a cadet.
GA Driver: It's changed to speed brakes 'as required' because initially it said speed brakes 'full', which has the issue of slow retraction, but also the increase in VLS.
I know you'd never let it get to this, but just out of curiosity on descent (managed) you see a 20+kt speed trend vector, (high on slope, increasing tailwind, whatever the cause) you are already at target 320kt SPD +20kt (say 340 heading for 350kt Vmo. Are you saying you wouldn't use speed brake in the first instance? (Push speed / v/s zero ain't gonna cut it in time), would you be advocating exp desc, or manual flight before SPD brake?
I know you'd never let it get to this, but just out of curiosity on descent (managed) you see a 20+kt speed trend vector, (high on slope, increasing tailwind, whatever the cause) you are already at target 320kt SPD +20kt (say 340 heading for 350kt Vmo. Are you saying you wouldn't use speed brake in the first instance? (Push speed / v/s zero ain't gonna cut it in time), would you be advocating exp desc, or manual flight before SPD brake?
This type of event has been discussed in detail before.
Keeping the autopilot connected is important, because of the reduced longitudinal stability at high alt.
As an aside, exactly the same thing has happened before in my company on a big airbus over the himalayas. Same thing (tho they were in level flight). The skipper was also out of the flight deck on a comfort break. FO got into alpha prot and ended up descending a couple of thousand feet (triggering a TCAS RA on the way down).
Disconnect the AP at your peril.
Keeping the autopilot connected is important, because of the reduced longitudinal stability at high alt.
As an aside, exactly the same thing has happened before in my company on a big airbus over the himalayas. Same thing (tho they were in level flight). The skipper was also out of the flight deck on a comfort break. FO got into alpha prot and ended up descending a couple of thousand feet (triggering a TCAS RA on the way down).
Disconnect the AP at your peril.
Don't forget you can increase the A/P pitch authority by using the speed brake. You only need to crack it for the increased authority.
Boomerang, crack the speed brake and select a slower speed, say 300 initially, then use speed brake as required. The increased pitch authority will do the rest.... Maybe.. And if it doesn't who cares.
A320 tested Vd is 380 kts and M0.86. Accept the Overspeed. She won't fall apart.
Boomerang, crack the speed brake and select a slower speed, say 300 initially, then use speed brake as required. The increased pitch authority will do the rest.... Maybe.. And if it doesn't who cares.
A320 tested Vd is 380 kts and M0.86. Accept the Overspeed. She won't fall apart.
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Its really important to keep Autopilot on , just wind speed back to about .75 and watch and wait.if it goes beyond the red so be it , the wings do not detach at the red line. Had one drift up to 360kts once no issues only a tech log entry and quick inspection. The speed brake drill was not in affect then.
I'm with you. Bula, I was just curious as to what GA Driver was trying to get at. At least in our company speed brake use is the FCOM method for handling an overspeed.
As Keg suggests, the key here is also all the things that lead up to the overspeed, threat/error management etc. That's harder to teach I guess than an FCOM procedure, certainly, it takes more time, and with a bit of time you get to observe such things on the line with an experienced pilot alongside you. If you are unlucky it happens on day 1, when the Captain has gone to the loo.(I have no idea what the situation or experience levels were on this incident)
I'm lucky I have 8 years and counting of observation on the magical mystery bus so far :-) and I'm still learning
As Keg suggests, the key here is also all the things that lead up to the overspeed, threat/error management etc. That's harder to teach I guess than an FCOM procedure, certainly, it takes more time, and with a bit of time you get to observe such things on the line with an experienced pilot alongside you. If you are unlucky it happens on day 1, when the Captain has gone to the loo.(I have no idea what the situation or experience levels were on this incident)
I'm lucky I have 8 years and counting of observation on the magical mystery bus so far :-) and I'm still learning
Boomerang absolutely agree with your methodology with the set of circumstances you suggest i.e. on descent with tailwinds etc etc. But even that can depend on where in the descent you are.
I was responding more to flexible response's statement about 'especially at high altitude' and seeing the topic of this thread is climbing from 360-380 I strongly disagree that use of speed brakes at that altitude should be the primary method as was posted, thats all.
I guess it will come down to what you see at the time as to the crews reactions, but on the day to day ops I see, usually I don't have that flexibility of a blanket 'speed brake in the cruise' at the weights/altitudes I see.
I obviously have no clue on who operates what type in this thread, but I do know the 320 and particularly 321 is a lot different than the big 330 on this very issue. 330 didn't seem to have any troubles throwing out the anchor. Just some food for thought.
I was responding more to flexible response's statement about 'especially at high altitude' and seeing the topic of this thread is climbing from 360-380 I strongly disagree that use of speed brakes at that altitude should be the primary method as was posted, thats all.
I guess it will come down to what you see at the time as to the crews reactions, but on the day to day ops I see, usually I don't have that flexibility of a blanket 'speed brake in the cruise' at the weights/altitudes I see.
I obviously have no clue on who operates what type in this thread, but I do know the 320 and particularly 321 is a lot different than the big 330 on this very issue. 330 didn't seem to have any troubles throwing out the anchor. Just some food for thought.
Last edited by GA Driver; 30th Jun 2014 at 07:26. Reason: Sppheeling x2
Lastly, was this incident caused by the F/O trying changing level using V/S? That only works on descent, in climb you stall, or get close.
I do agree though that most of the time VS is not a good idea for climbing, and certainly in this case it appears it was not the most appropriate mode.
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Good to see great discussion
Some gems of wisdom have appeared, in no particular order I'd like to:
hats off to Flexible Response for the airmanship issue of keeping your hand on the S/B lever until you are finished with it.
gold stars to GA driver and Bula about use of the S/B particularly at high altitude. That red zipper will jump on you faster than a Thai F/A raiding the food cart.
thumbs down to Der Fred - anything can be taught in the SIM - that's why they were invented. It's just that you need the willingness and the budget to do the training.
Cheers,
Ned
hats off to Flexible Response for the airmanship issue of keeping your hand on the S/B lever until you are finished with it.
gold stars to GA driver and Bula about use of the S/B particularly at high altitude. That red zipper will jump on you faster than a Thai F/A raiding the food cart.
thumbs down to Der Fred - anything can be taught in the SIM - that's why they were invented. It's just that you need the willingness and the budget to do the training.
Cheers,
Ned