2 Attachment(s)
Originally Posted by BugSmasher1960
(Post 9474751)
It's starting to look like one of those accidents where a number of opportunities existed to "fix the immediate problem":
1. If the TOGA function is inhibited due to A/C being on ground then get an automated voice to call out "MANUAL THRUST REQUIRED" or some other warning. 2. Or "Don't inhibit TOGA operation if nose wheel isn't on the ground" (or would that be more dangerous if hit accidentally at the wrong time?) 3. Pilots change SOP to shadow thrust levers Probably a few more minor variations as well. Here are two examples: |
Muscle memory shouldn't be 'click TOGA'. It should be - power up, It seems to be a link in the chain that has contributed to the accident when linked alongside wind-shear, possible fatigue, etc |
Compressor stall - I agree. I use - 'advance throttles, click TOGA' instead of 'click TOGA, verify throttles advance'.
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Lost In Saigon, fundamentally flawed procedure because there is no call to either command the setting of, or checking that GA thrust has actually been set. At least, if all else fails, a blurted-out call that tells the PM to set (or check) that GA thrust has been achieved will (hopefully) save the day. Similarly, if the PM has to make a call "Thrust set" then there is a better chance he/she will actually do it. I assume you do it on every takeoff; why not on a GA?
Compressor stall - I agree. I use - 'advance throttles, click TOGA' instead of 'click TOGA, verify throttles advance'. |
I remember a story,recounted to me by one of the protagonists,many years ago.Reminded me to ALWAYS keep my hands on the thrust levers,during commanded thrust changes,and I have passed it on,time and again.
Boeing 757,white hat brigade,take off phase... Just after climb thrust called for,the PM called "engine failure",the PF confirmed and began the memory item procedure...When he arrived at the thrust lever,he found it already closed.:confused: I believe,at that time,FLCH was the preferred method,for climb thrust,and before speed increase for flap retraction.(!). The left hand thrust lever had remained at takeoff thrust due some FADEC or physical obstruction problem,resulting in the speed mode of FLIGHTLEVEL CHANGE,commanding the only moveable thrust lever to adjust the overall thrust to maintain the FMC speed command...BINGO!!!!! A better demonstration of the wisdom of the hands-on approach,I can't imagine. RAT 5.. I think we were neighbours..130 hours in one month,?.FTLs, where provision of IRS allowed the 8 hour limit to be extended somewhat,and then some! |
Perhaps there is need for Gear-Up Inhibit logic.
If ( on 2 engine) if not at least one engine spooled up and producing 90% thrust, stop gear from coming up. If 4 engines, at least 3 engines not at nn% thrust stop gear from coming up.... Well, something like that just might help next time. |
Originally Posted by RiSq
(Post 9474510)
To be fair - the over reliance on Automation is a vicious circle.
A lot of carriers discourage manual flying and I know of some that will actively punish those that break such SOPs. The swing of that is, when the automation fails, its a case of crash and burn (Pardon the pun) Truth is - to these airlines, you (Pilot), Me (PAX) don't really matter - the only time we do is when one bites the dust and lets face it - it's easier to blame the dead crew than actually get a handle on the core issues - probably cheaper too! Training - Manual Flying - Working hours. It all stems back to a capitalist market, where profit is more important than safety. The irony is, the big carriers would rather spend millions of dollars trying to repair a Hull to avoid a write off then they would on training crew and improving safety. It seems bizarre to me that one major, at least, prohibits manual thrust operation BUT allows despatch with AT Inop. The captain of the A320 which lost its cowls, had never, according to the AAIB report, flown the ac with manual thrust and then had to resort to split, PF PNF, speed control. If an airline is employing captains who can't decide where and when to do a little hand flying to maintain skills they have the wrong people in the LHS! ......or perhaps they have the wrong people making such management decisions! |
Originally Posted by Lost in Saigon
(Post 9474922)
I bet most airlines' SOP already have a requirement for both the flying pilot, and the non-flying pilot, to each verify that sufficient go-around thrust is set.
Here are two examples: Is that the best place for it, in light of what we've just witnessed? |
1. If the TOGA function is inhibited due to A/C being on ground then get an automated voice to call out "MANUAL THRUST REQUIRED" or some other warning. A completely dead button is one of the least useful things on an aircraft. |
How about this for a solution...call the FMA? This wouldn't of happened had there been an SOP for them to do so. I currently fly the 767...go around procedure here is "go-around...3GA (read off the FMA)...Flap 20". If there was no auto throttle you would notice very early in the piece. Seems a lot more logical to have this be standard practice than come up with some silly "keep the gear down" procedure or some of the other creative ideas I've read.
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Fix the machine before attempting to 'fix' the human.
It would be difficult to change (and guarantee) the behaviour of thousands of pilots flying a particular type, but it is easier to change the logic of the auto throttle system in a few hundred aircraft, and at a lower cost (but who's cost?). Technical cost now vs escalating damage to the product name. Perhaps in this accident we have the one operator who has sufficient 'clout' to persuade the manufacturer to think again. |
Originally Posted by RetiredBA/BY
(Post 9475138)
Just WHY do some carriers discourage manual flying, surely an essential element to maintain flying skills to enable them to deal with the unexpected, but possible.
It seems bizarre to me that one major, at least, prohibits manual thrust operation BUT allows despatch with AT Inop. The captain of the A320 which lost its cowls, had never, according to the AAIB report, flown the ac with manual thrust and then had to resort to split, PF PNF, speed control. If an airline is employing captains who can't decide where and when to do a little hand flying to maintain skills they have the wrong people in the LHS! ......or perhaps they have the wrong people making such management decisions! I couldn't agree more. |
David Kaminsky-Morrow in Flight Global gives a useful reminder of what we know so far. It's dated 11 Aug, so apols if you've already noted it - I couldn't find it mentioned here.
https://www.flightglobal.com/news/ar...0120000000taAh airsound |
Originally Posted by PEI_3721
(Post 9475415)
Perhaps in this accident we have the one operator who has sufficient 'clout' to persuade the manufacturer to think again.
(1) Show that the landing gear were down (not up, not in transit) during the Go Around from decision point to impact with the ground. That is as yet not determined as a fact of the case one way or the other, though the initial report of "gear collapsed" (?) may be found to have relevance ... or not. (2) Determine whether or not the engines responded as expected and as required during the Go Around once the decision to Go Around was made. Looking forward to the findings of the investigation. |
Capn Bloggs - "Hmm, clicking and verifying movement definitely confirms TOGA has been engaged; pushing up then clicking doesn't confirm TOGA unless you also refer to the engine instruments/thrust limit. If you remove your hand (for, say, controllability) the throttles might come back if TOGA did not engage..."
Controllability? There's no need to remove your hand from the throttles at that time. HOTAS is still a concept applicable to today's flying. |
Lonewolf, caution noted; there was no intent to chase solutions for this event, which may only have limited value as accidents are rarely repeated in every detail.
We can wait until the 'facts' are available, but all that might do is confirm what happened during this accident, and provide little guidance as to avoiding the next one. However, from the discussions in this forum there appears to be strong evidence for safety concerns about the AT system. The greater the level of safety in aviation the more the need to pay attention to 'small' issues. |
Originally Posted by PEI_3721
(Post 9475667)
The greater the level of safety in aviation the more the need to pay attention to 'small' issues.
|
Lonewolf, we agree about the pilot out of the loop.
The need is to address the total man-machine-environment system. Generally the industry has a good record with AT systems; I know of at least one other aircraft which had similar logic to that in the 777, but, now 23 yrs on, without any problems. What strikes me as a difference is the 'recent' need to consider bounced landings, particularly in larger aircraft, and thence using automatics to trigger a simple manoeuvre (environment-design-training/behaviour). Why a difference, what has changed, why, apparently, is this only a problem with larger aircraft ??? |
Originally Posted by PEI_3721
(Post 9475927)
Lonewolf, we agree about the pilot out of the loop.
The need is to address the total man-machine-environment system. Generally the industry has a good record with AT systems; I know of at least one other aircraft which had similar logic to that in the 777, but, now 23 yrs on, without any problems. What strikes me as a difference is the 'recent' need to consider bounced landings, particularly in larger aircraft, and thence using automatics to trigger a simple manoeuvre (environment-design-training/behaviour). Why a difference, what has changed, why, apparently, is this only a problem with larger aircraft ??? |
I have some serious doubts that "the machine" is the issue. In the past 20 years, what has changed more: how the industry prepares pilots to fly, or the machines themselves? The B777's TOGA inhibit function has been with us for a long time. It was designed and certified that way for a reason, over 20 years ago. Some airlines recognised the 'problem' many years ago and have trained their pilots accordingly. My employer has been doing it for over 10 years and the associated procedures are in our B777 FCOM. Why aren't other airlines doing the same? You can hardly blame the aircraft if the pilots that fly it haven't been properly trained. We train V1 cuts, missed approaches from the minima and other 'canned' manoeuvres until the cows come home. Perhaps it's about time airline training started to incorporate some of the other, less traditional, 'events' that are likely to catch people out? How about engine failures at other points during the take-off profile, eg during rotate, V2, thrust reduction? Missed approaches from somewhere other than the minima, eg on the runway (rejected landing), from an altitude above the missed approach altitude? The assumption has always been that a pilot who is competent at flying a V1 cut or a missed approach from the minima will be well prepared for these other types of events. That may have been true once upon a time, when aircraft were much less sophisticated. It is not true nowadays, when there is much more reliance on automatic systems and their various idiosyncrasies. Aircraft design has moved on in leaps and bounds. Have our training/checking systems kept up? |
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