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Air India Near Death Incident

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Air India Near Death Incident

Old 10th Oct 2010, 03:27
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cheers for that PJ2

Would have been interesting to know what actually was the automation target speed during that early level off and what exactly made the capt doubt about the validity of the autothrottle reaction.
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Old 10th Oct 2010, 04:04
  #22 (permalink)  
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faheel;

For my part I fully comprehend the rapidity with which these operations can occur. That's why the departure briefing is critical and the full use of the automation is required. I gave up hand-flying London departures years ago simply because the autoflight system did it better and more accurately. There is a time for manual flight and departing Heathrow is most definitely not one of them. While not quite the silliness of the DEL SID, the Compton departure off 23R often levels at 6000ft - a trap for young players or a crew that isn't on top of the game as that is also the transition altitude and one must remember to set standard pressure immediately upon being cleared higher. It can be even much busier elsewhere and I know you'll have experienced exactly that.

The fact that this pilot is having to resort to sharing information here on an anonymous aviation forum is not good, it is shameful and a condemnation of Air India's flight safety system and operational culture. I still have no responses to the questions I have asked and that, at this stage of the thread where it is certain that people in the know would have the answers but haven't said anything, is revealing.

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Old 10th Oct 2010, 04:32
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While the "report" mentions the possibility, the B777 autothrust does not reduce to prevent "overspeed" of the flaps - in fact no transport's autothrust I have flown does this. There is a load relief function which will accomplish this however. Autothrust is targeted for the FMS or selected speed. On the Airbus, (and I agree, it is a waste of bandwidth to turn this into an A vs B commentary), but the autothrust also targets "over and underspeed" flight circumstances.
The 744, in normal takeoff/climb modes, will prevent flap overspeed. Normally TO/GA is the selected pitch and autothrottle mode, and V2 is set in the MCP. When the autopilot/FD transitions from TO/GA to VNAV, the MCP speed window closes, and speed is controlled by pitch (either by the autopilot if engaged, or manually following guidance from the Flight Director). The current flap limit speed is set by the FMS as the limit speed, so flap overspeed protection IS provided.

HOWEVER, I have no experience in using the autopilot with such a low level-off altitude. I do not know for sure how well the 744 would handle it, so I tend to fly those manually at least until the airplane is stable at the level-off altitude. There are those in the 744 community who would recommend going directly to FLCH after 400' AGL in similar situations -- especially if VNAV ALT was not captured) to reduce the rate of climb and ensure the Autopilot/FD and autothrottles exit TO/GA. I would not disagree with that technique.

Frankly, in that situation the flap limit speed would be among the LEAST of my worries. Keeping above V2 and VERY close to the target altitude would be my primary concerns. ACARS WOULD immediately report the flap overspeed.

A couple hundred people were VERY lucky that there was a 3rd pair of eyes AND a 3rd brain at work on this flight.

In the US we at least have the NASA ASRS reporting program to use without fear of retribution. Many airlines have the ASAP program as well, but it's not confidential like ASRS is. It's too bad the situation is so bad over there in India...
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Old 10th Oct 2010, 06:36
  #24 (permalink)  
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The current flap limit speed is set by the FMS as the limit speed, so flap overspeed protection IS provided.
Thank you Intruder. Am I correct in understanding that the autothrust does not "see", on its own, the flap limiting speeds and will exceed flap speeds should the constraints not be in the FMS. I suspect that in FLCH, the flap speed would be exceeded, or do I have this wrong? The situation you describe is a good one, (Flap speeds in the FMS), however, I suspect the speed is controlled by pitch, not thrust, (which can be a problem in such an early capture) in terms of aircraft stability.

Such an early capture brings up another latent problem: The "Alt*" (altitude capture) characteristic, which, while first demonstrated tragically by the A330 at Toulouse, applies equally to Boeing. I wonder if this is what occurred here?

It depends upon how much the flap speed was exceeded by and what flap setting was out. I suspect more than a few here have exceeded flap speeds by a few knots for a few seconds. While not good for the slats/flaps and mainly for the flap support structure, a catastrophic failure of the flap system is not normally the result. In other words, such infrequent excursions aren't likely to damage them and in my view such an excursion wouldn't necessarily result in a decision to dump fuel and return to the airport. However, only the on-board crew can make that call, especially if the overspeed was substantial or for an extended period of time.

Anyway, all this is beside the point and off-topic. The main point here is very clear to all - a possible loss-of-control almost-certainly fatal accident avoided due to quick thinking. Now what?

PJ2
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Old 10th Oct 2010, 07:00
  #25 (permalink)  
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While I now fly the 777 and am in awe of the control/thrust/autopilot systems, this crew did something a DC-8 or B-727 crew would never had done.

They didn't control airspeed. Plain and simple. It's happening with increasing frequency these days - as our MD-10 in the high holding pattern showed a few years ago.

Open the speed edit box, set it at 200 knots, let the damn thing stabilize, see what you can do about cleaning up. Fly the damn airplane.
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Old 10th Oct 2010, 08:34
  #26 (permalink)  
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A salutory tale.

It seems we are off on a few incorrect tangents, however?

1) Reading 'Lesson f' suggests the Captain was not an ex-pat, so some of the comments here may not be applicable

2) It does indeed sound like the 'alt*' event which I know from the 737 well. A low-level level off is by no means unusual and needs to be carefully briefed due to this. It can be common in Tel Aviv. It is easily handled as a crew.

3) The 'CVR download' in JFK would be a waste of time unless our poster had pulled the CB which would, it seems, have been a death sentence.

4) The intitial reaction of the Captain in disconnecting the A/T is understandable but not excusable. The Captain should have expected, briefed and known what would happen. It is "Lesson 1" in how to deal with automation - if it appears to be malfunctioning turn it off and revert to basic flying skills The latter part did not happen.

The demonstrable existence of such fear of reporting is of serous concern. Surely an FDR would be fitted and that could have been downloaded? If we are in yet another 'culture/status' driven area of operations then some international body needs to wake up.
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Old 10th Oct 2010, 08:37
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What actually happened here is that the AFDS captured the low leveloff very early (evidence FMA VNAV ALT). The AFDS sub-mode (not displayed on modern Boeings or Airbusses) is V/S. In this sub-mode the AFDS tries to follow a parabolic arc to level off at the captured altitude using pitch control. The A/THR has speed but is respecting only the low speed limit. VFE is ignored in this submode.
As suggested, the best way (but not the only way) to handle a low level off with automation is revert to FLCH. This puts the A/THR back in charge of the speed, not guarding it.
I too have been given the low level off at DEL. I rejected it and sat on the runway until I was given a more reasonable level off.
Like PJ2 I wonder about the SMS at AI.
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Old 10th Oct 2010, 08:47
  #28 (permalink)  
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3-wire - do not fly to Nice - you'd be there all day waiting on 04
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Old 10th Oct 2010, 09:08
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I am not saying all automation is bad, quite the contrary, it is great to have, however it seems that a lot of crew simply slip 'out of the loop' accidently with the fixed mindset of letting the AP fly - especially near the ground.

What happened to hand flying to 10000ft, or at least the initial portion of the SID?

Maybe it's just me, but in a two-man flt deck there should be plenty of capacity for one the hand-fly and the other to run checklists and radios.

I am not saying people should hand-fly in crap weather conditions for the sake of it, but they should certainly be prepared to do so at any time. If both get preoccupied with checklists or the autopilot, none is monitoring the actual flying.

Think about it this way... we'd have probably read about this in the papers wouldn't it have been for the SIC on the jump.
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Old 10th Oct 2010, 09:18
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What actually happened here is that the AFDS captured the low leveloff very early (evidence FMA VNAV ALT). The AFDS sub-mode (not displayed on modern Boeings or Airbusses) is V/S. In this sub-mode the AFDS tries to follow a parabolic arc to level off at the captured altitude using pitch control. The A/THR has speed but is respecting only the low speed limit. VFE is ignored in this submode.
You may be correct for the 777, but not for the 744, according to the books I have. VNAV ALT is a VNAV mode, not a V/S mode, and the autothrottles go to SPD mode when VNAV ALT is captured. Target speed would be MCP speed if the window is open, or FMS commanded speed (could be V2+10 or accelerating, depending on altitude) if the window is closed. The FMS still provides high- and low-speed protection when the MCP speed window is closed.


PJ2:

The autothrottles don't "see" anything on their own. They are controlled and limited by the FMC.

In FLCH the speed is controlled by the MCP window, since it opens automatically when FLCH is selected. IIRC, flap limit speeds are not honored when the MCP speed window is open.
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Old 10th Oct 2010, 09:31
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Few years back, i was on descent into Mumbai and cleared to 11000ft. Indian Airlines Airbus was cleared to climb to 9000. To cut the story short, he climbed through it and hell broke loose. Hard RA and we climbed out of the way. Whew!
I filed a report and rang the chief pilot, who begged me not to file the report. Something about having an ace up the sleeve, next time the authorities did an audit on the compay.
I resigned and had left India within the week!
When i left India, the number was up to 35 near misses a year. I sometimes wonder how many WERENT reported!
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Old 10th Oct 2010, 09:43
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<<the Compton departure off 23R often levels at 6000ft >>

Now there's a man who hasn't been to Heathrow for 50 years as 23R simply does not exist. "Often levels at 6000ft"?? If I recall correctly all except one of the the Heathrow SIDs level at 6000ft and that has been the case for donkeys years.
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Old 10th Oct 2010, 10:05
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Im gonna deviate abit....

ITS been a coupla years since i flew the big bird, but I vaguely remember that the B777 A/Ts are never really off...and at Vls(low speed) they kick in just enough to maintain speed at or slightly above Low speed Buffett irrespective of their posn ie off or armed....any to clarify?
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Old 10th Oct 2010, 10:19
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if it appears to be malfunctioning turn it off and revert to basic flying skills The latter part did not happen.
same applies to if you do no longer understand what it does. With all the automation and its submodes this happens faster and more often than we all like. The one pilot who pretends this has never happened or will never happen to him, due to his superior system knowledge is simply a liar.

Concerning reverting to basic skills, now there's a thing that scares me most. I've seen too much absence of such skills recently as to believe in coincidence.

We will never have automatics that are fool proof, we will never completely and continuously be aware of all modes and features of automation. We should, at least for the foreseeable future, still be able to revert to basics and reengage automatics once stabilised. This beeing neglected in basic and enhanced training, and thus lost forever, will lead to such incidents happen more often.

The perpetuous call for even more protections and automatics will always only cure some symptoms, but not aviations malaise -> lack of skill and experience.
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Old 10th Oct 2010, 10:46
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If the airline doesn't have Flight Data Analysis (FOQA) don't fly with it or on it.
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Old 10th Oct 2010, 11:04
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Having flown the 777 for the company involved I can believe something like this could have happened, however some things need clearing up in regard to 777 operations. After T/O after acceleration height, FMA changes from TOGA to THR REF/LNAV/VNAV SPD ie. A/Ts set reference thrust on the engines, LNAV captures and VNAV speed is maintained by pitch attitude through the A/P or F/D which at this point is 230 knots (flaps 5 speed minus 5 knots) this speed is indicated as the target airspeed above the ASI (speed window is closed). If at this point FLCH is selected, again THR REF and LNAV unchanged, and FLCH is engaged, speed window opens indicating a target airpseed of 250 knots (below 10,000') and A/P or F/D maintains airspeed throught pictch angle.
There is no need to hand fly low level hold downs, the A/P has logic to anticipate this in FLCH or VNAV, and in fact at heavy weights close to the ground automation makes sense (even more so in that part of the world where manual proficiency is not maintained).
The 777 does have low speed protection even with the A/Ts selected off, and they would have enagaged automatically to prevent speed decreasing to near Vs (which even at heavy weights would be closer to 100 knots than 200 knots with flaps 15 still set). When the aircraft was accelerated using manual thrust and still climbing in FLCH the A/P would have mainted 250 during the climb, and any overspped condition would have been prevented by the load relief system.
To suggest pulling a CVR CB at the begginng of a 15hr flight is probably not prudent, as anything could happen after this point that could need to be recorded (ie. incident on approach), and the FDR would record all the parameters and selections anyway.
A valuable lesson learned hopefully for the crew involved, and I would expect that someone would notify the airline so that they can prevent it happening again.
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Old 10th Oct 2010, 11:59
  #37 (permalink)  

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Safety

Just a thought, but shouldn't the best and more experienced crews be those selected for operations such as B777 Delhi-JFK? The report suggests a combination of incompetence and inexperience in the front 2 seats of this particular near-disaster. With a consequent cover-up to boot.

I fear that nepotism over-rules ability-based qualification for "good" jobs in many countries like India and in many airlines similar to Air India. I am being direct and politically incorrect here, but am by no means having a pop at AI specifically. I just believe that the democratic systems in place in major US/North European/Antipodean carriers have little or no place for nepotism. Their safety records reflect this.
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Old 10th Oct 2010, 12:03
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"Often levels at 6000ft"?? If I recall correctly all except one of the the Heathrow SIDs level at 6000ft and that has been the case for donkeys years.
Yup, that is what I recall as well...and we normally did just that, nearly every time, hand flown did not present a particular problem....even the First Officer could do this quite well, so....what's the beef?

DEL, on the other hand, is obtuse in the extreme with ATC demands...expect the unexpected.
Par for the course.
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Old 10th Oct 2010, 12:17
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On a B777 you can not pull the CVR circuit breaker.

It is not located in the cockpit, the CB is in the electronics bay below the cockpit. You need to open a hatch in the floor at door 1L and don't forget to bring your portable oxygen when you go in there during flight.

Frankly I don't understand WHY the CVR CB is located THERE. beats me. Ask Boeing.
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Old 10th Oct 2010, 12:51
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Furthermore, it's against of the SOPs on majority of the airlines to go manual at will.
The SOPs at most carriers are a guide for safe flight under normal circumstances and do not constrain common sense.

There are situations, as described in this low altitude level-off, in-a-turn, fast-moving scenario, where the automatics may not have been set properly, or for whatever reason may not deliver the required profile. A common mistake I have noticed by many new pilots is their obvious hesitation in disconnecting the automatics and going manual. Their first impulse is always an attempt to correct the flight profile with more automatics.

After the THY B738 stall and crash at AMS, Boeing has clearly stated: "When the automatic systems do not perform as expected, the PF should reduce the level of automation to ensure that proper control of the airplane is maintained. The PF should not attempt to restore higher levels of automation until after aircraft control is assured."

Practical reality suggests that pilots should not be trained to have an aversion of hand flying the machine at will.
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