AA757 Near Stall - Recovery Caused Injuries
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Some questions about the formula/diagram:
- LWBN and LT do seem to have the same direction, whereas I would expect the LT to be downward in the diagram, otherwise the sign in the formula should be different. Just like TZT and TZD do have different signs in the formula. So, I think, it works out fine, though it's confusing.
- The Datum location is irrelevant for Moment calculation, as long as there is no rotation, though once rotation sets in, it needs to be in the rotation point, to let the Moment calculation work. The formula does suggest a general purpose validity, and does not suggest a zero angular velocity/acceleration. Correct ?
- LWBN and LT do seem to have the same direction, whereas I would expect the LT to be downward in the diagram, otherwise the sign in the formula should be different. Just like TZT and TZD do have different signs in the formula. So, I think, it works out fine, though it's confusing.
- The Datum location is irrelevant for Moment calculation, as long as there is no rotation, though once rotation sets in, it needs to be in the rotation point, to let the Moment calculation work. The formula does suggest a general purpose validity, and does not suggest a zero angular velocity/acceleration. Correct ?
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“… some sort of parallel universe a few years ago - one in which pilots don't know how to fly, or scan their instruments?”
“… no aircraft accidents in history prior to 2015, and no recorded occurrences of pilot error.“
‘Safety’ depends on context, the viewpoint, as chosen by the observer.
‘Safety’ as something to have, to be; or as all of the activities undertaken every day, and not as imagined.
‘A Statistical Analysis of Commercial Aviation Accidents 1958 - 2021’
https://accidentstats.airbus.com/sit...-1958-2021.pdf
Page 17
“… no aircraft accidents in history prior to 2015, and no recorded occurrences of pilot error.“
‘Safety’ depends on context, the viewpoint, as chosen by the observer.
‘Safety’ as something to have, to be; or as all of the activities undertaken every day, and not as imagined.
‘A Statistical Analysis of Commercial Aviation Accidents 1958 - 2021’
https://accidentstats.airbus.com/sit...-1958-2021.pdf
Page 17
Oh, OK then. So nobody else is worried that supposedly trained and qualified pilots - even Captains - are crashing or nearly crashing because of very very basic piloting mistakes or omissions?
Fair enough.
Fair enough.
ALF5071H makes a valid observation that over time flight safety has improved markedly, and that is true, the concerns and the historical improvements are not mutually exclusive.
Aviation systems of display, alerting, warning, and design have improved greatly over time, yaay. Planes don't fail structurally as they used to do, and pilots don't get lost as often as they did.... What we are left with exposes the obvious issues of crew-centric matters, both good and bad. Whether basic competency has altered over time is not confirmed, the weighting of events that competency is questioned is more evident. Even without empirical proof that there is a change, that a children of the magenta really is a factor, the system response to the residual events remains inadequate.
Further observations from the safety statistics.
A comparison between different generations of aircraft strongly suggests that technology has improved safety. However, as the new generation aircraft are still crewed in the conventional sense, then the technology and associated training will have reduced the human contribution in incidents. There are fewer accidents overall, the human contribution has reduced, i.e. pilots of gen 3-4 aircraft appear more capable - better matched competency - the combination of man and machine.
Exceptions would be in older generations where there are many gen 3 aircraft which were designed as gen 2, but with system updates pretend to be gen 3; e.g. B 737, F100, ARJ, and B 757.
The perceived training and proficiency issues in current operations with older generation aircraft could be due to crews being exposed to other factors, e.g. older aircraft in a new aircraft operational environments.
Also that safety management has moved away from accidents (very few of them), to focus on events, which previously could have been accepted as normal, and not necessarily ‘unsafe’ depending on outcome.
Modern aircraft with event auto reporting or FDR analysis might proportionately identify more safety events, but are not less safe because of knowledge and investigation.
Operations without reporting could experience the same event, remaining unknown, similarly not less safe.
The industry assumes too much about the human contribution, the ability to manage changes in design, training, and operation, particularly in older aircraft; there is a mismatch in man-machine (and operational situation) competency where substandard operation is inappropriately focussed on the human.
Safety is not so much about where a line is drawn it depends on who draws it, interpretations, judgement after fact.
A comparison between different generations of aircraft strongly suggests that technology has improved safety. However, as the new generation aircraft are still crewed in the conventional sense, then the technology and associated training will have reduced the human contribution in incidents. There are fewer accidents overall, the human contribution has reduced, i.e. pilots of gen 3-4 aircraft appear more capable - better matched competency - the combination of man and machine.
Exceptions would be in older generations where there are many gen 3 aircraft which were designed as gen 2, but with system updates pretend to be gen 3; e.g. B 737, F100, ARJ, and B 757.
The perceived training and proficiency issues in current operations with older generation aircraft could be due to crews being exposed to other factors, e.g. older aircraft in a new aircraft operational environments.
Also that safety management has moved away from accidents (very few of them), to focus on events, which previously could have been accepted as normal, and not necessarily ‘unsafe’ depending on outcome.
Modern aircraft with event auto reporting or FDR analysis might proportionately identify more safety events, but are not less safe because of knowledge and investigation.
Operations without reporting could experience the same event, remaining unknown, similarly not less safe.
The industry assumes too much about the human contribution, the ability to manage changes in design, training, and operation, particularly in older aircraft; there is a mismatch in man-machine (and operational situation) competency where substandard operation is inappropriately focussed on the human.
Safety is not so much about where a line is drawn it depends on who draws it, interpretations, judgement after fact.
Can somebody check my maths (never one of my strong points), but looking at the graph on page 14 in the link, in 1961 there were 9 hull losses per year and around 1 million flights. In 2017, there were 35.8 million flights per year. If the same accident rate had persisted, there would have been 346.5 hull losses in 2017 https://accidentstats.airbus.com/sit...-1958-2021.pdf
A stunning improvement by any measure even though there remains much to be done to improve crew training. Any thoughts or corrections?
A stunning improvement by any measure even though there remains much to be done to improve crew training. Any thoughts or corrections?
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Bottom line. On occasion, there is an issue where the aircraft is not maintaining the desired airspeed despite the pilots expecting it to do so. On rare occasion, this will happen during the briefing. On even rarer occasion, the pilot who is receiving the briefing while flying the aircraft will not be properly monitoring the airspeed.
Therefore, I suggest that the pilot doing the briefing make occasional, quick glances at the instruments while giving the briefing. Every 30 seconds or so might work out well as a good balance beteeen briefing and double checking.
Admittedly, one may be less vigilant when briefing during the cruise phase of flight, but vigilance should definitely be increased anytime a briefing is happening after top of descent.
Therefore, I suggest that the pilot doing the briefing make occasional, quick glances at the instruments while giving the briefing. Every 30 seconds or so might work out well as a good balance beteeen briefing and double checking.
Admittedly, one may be less vigilant when briefing during the cruise phase of flight, but vigilance should definitely be increased anytime a briefing is happening after top of descent.
Last edited by punkalouver; 23rd May 2022 at 11:31.
"Mildly" Eccentric Stardriver
punkalouver. I love your suggestion that pilots should check the instruments every so often while briefing. Whatever happened to "check; cross refer; check again"? Something I remember from famil 1, which in my case is some 57 years ago.
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I think it will be effective. When I see incidents happen, I am interested in solutions that a pilot can use to prevent it from happening again. Comments about how pilots are not as good as they used to be or sometimes the frequent blame management idea provide little to no assistance to the pilot pilot interested in a solution for their next flight.
Can somebody check my maths (never one of my strong points), but looking at the graph on page 14 in the link, in 1961 there were 9 hull losses per year and around 1 million flights. In 2017, there were 35.8 million flights per year. If the same accident rate had persisted, there would have been 346.5 hull losses in 2017 https://accidentstats.airbus.com/sit...-1958-2021.pdf
A stunning improvement by any measure even though there remains much to be done to improve crew training. Any thoughts or corrections?
A stunning improvement by any measure even though there remains much to be done to improve crew training. Any thoughts or corrections?
The concern in the early 70's was that the rates of losses were so high that the expected expansion of global aviation would result in unacceptable headlines every day, as you indicate. EGPWS/TAWS/TCAS/EFIS/ECAM-EICAS/GNSS etc helped, and additional protective warning modes were added to warning systems, which also became conditional to assist the crew in making appropriate decisions.
The crew have been losing control of aircraft since the start of aviation, the concern remains that loss of control generally results from a failure of SA and we have much more advanced tools for the crews to mitigate that yet it continues. The losses in most cases make depressing reading with very few novel manners of losing the plot being disclosed. The HITL is still the current most effective way of mitigating the gap between planned design behavior and system reliability. Automation inherently places the human into a process that they are less effective at over time, that of monitoring, and frequently that is a primary factor in the divergence from the desired state to the actual state. The recovery from an anomalous state often is at the end of the spectrum of responses from nothing or inadequate through to excessively aggressive with possible adverse consequences, e.g., Lauda's TR event was time-critical, AA587 needed a gentle response, both events had critical information that was not self-evident before the event which in hindsight resulted in changes to procedures. SR111 is another case where there was a mismatch of procedures and needs, which generated some changes post-event.
Competency in dealing with recognition of time-sensitive anomalies is a challenge but offers potential relief from such things as 260 kt low flying on takeoff, or wild rides in recovery from upsets.
Much like the '70s. management needs to look to new initiatives to reduce the residual events severities that exist now with current aircraft operations. Some stuff will remain depressing, like the turning off of all IRS's in IMC conditions... hard to mitigate unfathomable actions. Deliberate unlawful actions by the crew need more response than has occurred to date, and remain a blight on the industry. Post 9/11, the compliance with security protocols when audited varied from excellent to patchy, so protection from crew-caused illegal actions could also be variable depending on how seriously mitigation protocols (if any) are taken.
But you do look up from the plate or MCDU and glance at the PFD and engine instruments every so often as you brief - (even though you are on automatics) - surely?
Would it not be better to do your briefing when in the cruise shortly before top of descent when everything is quiet? That way it would be much easier to 'mind the shop' while going through the charts and plates. Then, only minor updates would be necessary later. Much better to plan ahead and sequence activities to avoid peaks of workload and/or distractions. A counsel of perfection I know but it can be done.
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Remember something. When the PF hands over control to start briefing, he has become the PM(Pilot Monitoring). Why would you stop monitoring whether it is while briefing or eating or filling out the logbook, etc.
Only half a speed-brake
WTHeck are we discussing here, sounds like the widebodies have a dedicated and separate briefing classroom or what? And 757 ain't one.
Last edited by FlightDetent; 24th May 2022 at 21:39.
@ punkalouver; exactly. Of course the main approach briefing should be completed before TOD. Not doing so was their first hole in the cheese.
Not monitoring the aircraft or the instruments was their second.
Not monitoring the aircraft or the instruments was their second.
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Not so quickly
It's just too easy to be a keyboard warrior. Thousands and thousands of safe flights everyday so I don't think it's appropriate to deduce from isolated incidents that pilots these days don't know how to scan and fly. Lessons to be learned for sure but no need to dramatize and generalize, I think.