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B737 Go-Around tragedy. Pilot error all over again
https://mak-iac.org/upload/iblock/45...vq-bbn_eng.pdf
Suggestion. Those readers who prefer to quickly get to the nexus of accident reports should skip the peripheral information which forms a great part of this first class investigation. This is where speed reading skills come to the fore. Otherwise by the time you gets to the guts of what went wrong in what should have been a normal go-around in a Boeing 737, you will suffer from reading fatigue, despite numerous cups of coffee. One way or another, depending on your bent, eventually you will reach that part of the report where the investigation sets up a series of go-around scenarios in the simulator and had ten 737 pilots fly the same procedure in IMC. Those results are seriously thought provoking and I wouldn't mind betting a high percentage of current 737 pilots today would likely have similar results. Some would even crash. Designers of simulator training syllabi would do well to learn from this report and ensure ample time is allotted to teach IMC low level go-around procedures as part of type rating training and proficiency checks. |
Pages 96-100...
Worthy of notice, the seemingly lack of/ fake qualification of the accident PIC and the mention of "dubious flight schools" for some pilots in the experiment. |
How about this non-Max crash. Seems awfully suspicious: Flydubai Flight 981. Is there a problem with A/P in these birds?
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Is there a problem with A/P in these birds? See https://mak-iac.org/upload/iblock/45...vq-bbn_eng.pdf page 219. & https://mak-iac.org/upload/iblock/3d...a6-fdn_eng.pdf page 166. "2.4. On the possible impact of somatogravic illusions. Somatogravic illusions have been noted repeatedly as a contributing factor during investigations of aviation accidents and incidents which involved go-arounds." |
Hi Golden
But isn't the basics of instrument flying is to only trust your instruments and not your feelings. Humans have no instincts in the air. Somatogravic factor comes in when the pilot is trying a pitch change without looking at the PFD and as a result it is too shallow. In FlyDubai copilot didn't suffer it because he was monitoring the pitch and guiding the PF perfectly. Unfortunately the PF had gone into the realm of the irrational. AF447 no somatogravic illusion but again commanding a pitch without looking at PFD. This loss of scan causes the problem. These are also procedural errors. |
Originally Posted by vilas
(Post 10648353)
Hi Golden
But isn't the basics of instrument flying is to only trust your instruments and not your feelings...... How many times have you seen crews in the simulator performing something mildly stressful and they are both shouting over the "C chord" altitude alerter - neither of them even notice it is on until the work load is reduced? I suspect the somatogravic illusion stresses the crew member to such an extent that they don't read the PFD correctly or may even disbelieve it. |
It doesn't matter how often you you may have practiced in the simulator (all at 1g and within the pitch limit geometry of the motion) apparently the illusion is powerful and can take some crews by surprise. |
Originally Posted by vilas
(Post 10648940)
I don't think pilots are trained to tackle any illusions at all because they cannot be created in the simulator.
This 2016 powerpoint from Cathay Pacific Group Safety department https://flightsafety.org/wp-content/.../11/Ludlow.pdf sounds like their Military pilots have received SGI training experience in flight. (Slide 38). It also has some very good advice about briefings for SGI avoidance, use of Autopilot and using reduced thrust during Go Arounds when possible. FlyDubai had lots of holes in the cheese lined up that night: Tired crew after long holding delay, light aircraft, full GA power due WS warning, single AP approach resulting in AP disconnect on initiation of the GA, etc. If only they had briefed SGI as a threat.....? |
Somatogravic illusions have been noted repeatedly as a contributing factor during investigations of aviation accidents and incidents which involved go-arounds." One thing noticeable in many accident reports involving a go-around accident at night or in IMC, is that authors of these reports are quick to use somatogravic illusions as contributing factors when they know there is no way of proving these were positively identified as present. A get-out-of-jail free, card What many investigators fail to realise, if the truth be known, is that the majority of these accidents are simply caused by poor instrument flying skills on the part of the pilot - not necessarily by the little hairs in your ear canals. Investigators at loss to explain the cause of an accident, can simply blame the spectre of somatogravic illusions, as if that explains everything. Their report can now be signed off because no one can prove otherwise.. |
Originally Posted by Judd
(Post 10649297)
Funny that aircraft carrier pilots are not crashing all over the world during thousands of catapulted takeoffs and wave-offs (go arounds) every year. After all, you can not imagine a more severe acceleration in these aircraft.
One thing noticeable in many accident reports involving a go-around accident at night or in IMC, is that authors of these reports are quick to use somatogravic illusions as contributing factors when they know there is no way of proving these were positively identified as present. A get-out-of-jail free, card It even happens to well trained fighter pilots. There is no means of simulating rotations and accelerations in the sim, and I doubt many airlines do practice aircraft upsets in a real plane, so I wouldn't be so affirmative re this "poor instrument flying skills". |
Originally Posted by Judd
(Post 10649297)
Funny that aircraft carrier pilots are not crashing all over the world during thousands of catapulted takeoffs and wave-offs (go arounds) every year. After all, you can not imagine a more severe acceleration in these aircraft.
One thing noticeable in many accident reports involving a go-around accident at night or in IMC, is that authors of these reports are quick to use somatogravic illusions as contributing factors when they know there is no way of proving these were positively identified as present. A get-out-of-jail free, card What many investigators fail to realise, if the truth be known, is that the majority of these accidents are simply caused by poor instrument flying skills on the part of the pilot - not necessarily by the little hairs in your ear canals. Investigators at loss to explain the cause of an accident, can simply blame the spectre of somatogravic illusions, as if that explains everything. Their report can now be signed off because no one can prove otherwise.. |
Somatogravic illusion could be avoided or at least minimized by performing a soft go around. Many skippers believe they need to keep MAX power until thrust reduction which leads to having way too much energy with all engines running. On Airbus a small tap to TOGA then back to climb detent when appropriate (or Flex/MCT detent if equipped with the Soft Go Around) will make the go around much safer. Less chance of illusion, overspeed and altitude burst.
The recommendation to perform soft go around can be found in the Airbus Safety First magazine #23. |
Fly Arpt
so I wouldn't be so affirmative re this "poor instrument flying skills". Somatogravic illusion could be avoided or at least minimized by performing a soft go around. |
Sure Vilas. It’s all about good sense and judgement. A320 especially the Neos are overpowered. , climb power on any A320 would give you more than 2000 feet /min which is more than required to comply with the mininum climb gradient. I have seen a fo going around at 800 feet ( it was a NPA), set TOGA and kept it until alt*. We were climbing around 4000 feet/min on A321. Alt* was triggered with a very high pitch and he immediately set climb power. As a result the speed dropped below VLS cause of the ALT* logic. It was not that serious but completely avoidable by keeping toga slightly longer or by having decided to perform a soft go around using climb power immediately after tapping TOGA. We had another case where the crew were instructed to go around, the Fo as PF immediately set TOGA but only pitch like 5/7 degrees up probably because of Somatogravic illusion. Captain failed to take over in time and due to the very high acceleration by using TOGA, they overspeed the flaps. I’m convinced if they had performed a soft go around they would not have overspeed. My point is of course we should be able to fly with TOGA; Some cases TOGA would be the safest option and monitoring is the key but why would you make your life more complicated when you don’t have to. Especially during a go around where most of the time you don’t expect it,and probably poorly prepared as in the simulator most go around are done in single engine which is much easier in term of energy management. Plus the fact that many skippers do not fly raw data anymore, how could you expect them to perform a safe go around with TOGA... |
We had another case where the crew were instructed to go around, the Fo as PF immediately set TOGA but only pitch like 5/7 degrees up probably because of Somatogravic illusion. |
Originally Posted by pineteam
(Post 10649392)
Somatogravic illusion could be avoided or at least minimized by performing a soft go around. Many skippers believe they need to keep MAX power until thrust reduction which leads to having way too much energy with all engines running. On Airbus a small tap to TOGA then back to climb detent when appropriate (or Flex/MCT detent if equipped with the Soft Go Around) will make the go around much safer. Less chance of illusion, overspeed and altitude burst.
The recommendation to perform soft go around can be found in the Airbus Safety First magazine #23. |
Goldenrivett, # 4
However, from page 169 “the complex analysis of all the information available, stated above, is the evidence that, most probably, both the intense forward repositions of the control column up to the initiation of the stabilizer trim to nose-down and the trim itself, had not been attributable to the PF (the PIC) having been affected by the “pitch-up” illusion.” “… the investigation team is of the opinion that the potential occurrence of the somatogravic “pitch-up illusion” did not have crucial importance as far as the onset of the accident situation is concerned. In the progress of the accident situation the pitch-up illusion might have had some impact on the long-time keeping the trim switches pressed to nose-down.” The issue of trim and continued forward pitch is discussed in the primary thread on the accident - https://www.pprune.org/rumours-news/...eport-out.html and specifically at https://www.pprune.org/rumours-news/...l#post10642086 Centaurus, is the issue of trim / pitch feel something which can be identified in simulation in the 737. |
During Instrument flying traning pilots are trained to manoeuvre the aircraft accurately purely according to the instrument indications. When a GA requires 15° pitch up but is executed at 4 or degrees isn't it poor flying? I will again say that it all starts with giving pitch inputs without looking at the attitude indicator. Training and awareness is key to survival in my opinion. When I have experienced it the problem is not one of poor instrument flying skills, nor lack of scan. It is a problem of perceived conflicting information. The sense that you are pitching nose high, almost to vertical, is so strong that the other sensed cue ( visual) of an AH at 15 degrees nose up is difficult to believe. The conflicting sensed information takes some processing and a decision has to be made to ignore the seat of the pants and go against every fibre in your body and maintain the AH pitch required. The second time you make this decision is much much easier than the first. Solid training and awareness of the illusion is key to being able to make the correct decision. A brief twenty minutes prior ( not that I’ve ever done this) would be hugely beneficial in avoiding the hazards of SI. |
Originally Posted by 73qanda
(Post 10649869)
I suspect you have never experienced SI. Training and awareness is key to survival in my opinion. When I have experienced it the problem is not one of poor instrument flying skills, nor lack of scan. It is a problem of perceived conflicting information. The sense that you are pitching nose high, almost to vertical, is so strong that the other sensed cue ( visual) of an AH at 15 degrees nose up is difficult to believe. The conflicting sensed information takes some processing and a decision has to be made to ignore the seat of the pants and go against every fibre in your body and maintain the AH pitch required. The second time you make this decision is much much easier than the first. Solid training and awareness of the illusion is key to being able to make the correct decision. |
We are made aware so that we don't react by feelings but to reality on the instruments which according to you is almost impossible. We get used to the sensation of pitch from pressure in our back and butt which agree with the ADI. In the real world, with an unexpected acceleration from full TOGA power and a light aircraft - then there can be a sensation / visual mismatch which can cause confusion. |
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