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Emirates B777 gear collapse @ DXB?

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Emirates B777 gear collapse @ DXB?

Old 10th Aug 2016, 19:40
  #761 (permalink)  
 
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My 2 cents worth

Its a shame if it turns out that this accident was the result of an over zealous gear retraction. Why are we so keen to retract the gear in a all engines operating GA? Its the least important thing to be doing. Thrust is more important and mode confirmation is more important. I have seen crews in sims permit a focus on LG retraction distract them from the bigger ticket items.
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Old 10th Aug 2016, 20:13
  #762 (permalink)  
 
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Originally Posted by SOPS View Post
Maybe, just maybe, EK pilots should be allowed to hand fly more? I have an email, from a certain DCPB, that states ' hand flying has no value in this company' . This was from a 'ping' in the early days when I hand flew the aircraft above 5000 feet. ( What made it even funnier, was it was on a line check, and I was told by the TRE doing the check, ' the good thing about EK, as long as you brief non standard stuff, you can do it.) Learnt my lesson there.

Just my thoughts. (But DCPB I still have that email, signed by you )
You must be Ozie coz they like to fly "hand fly" and is nothing wrong with that as long as your PM is happy coz hand flying creates additional workload on PM especially in a busy environment...
However hand flying will not improve your knowledge of SOP's clearly not followed by 521 crew
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Old 10th Aug 2016, 20:25
  #763 (permalink)  
 
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Originally Posted by Lost in Saigon View Post
Gear retraction takes time.

I suspect the gear was still being retracted when the aircraft settled onto the runway.
I agree, gear down takes app 30 sec to complete and gear up app 20 sec, assuming they did retract gear in a GA...
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Old 10th Aug 2016, 20:31
  #764 (permalink)  
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Originally Posted by bobdxb View Post
I agree, gear down takes app 30 sec to complete and gear up app 20 sec, assuming they did retract gear in a GA...
Out of interest - does the logic allow a gear 'reversal'? - ie will it lower halfway through an 'up' - or is it flip-flop (toggle)?
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Old 10th Aug 2016, 20:36
  #765 (permalink)  

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Just read a basic report supposedly from one of the pilots on social media... please don't shoot the messenger. Was a few mins ago on twitter and I can't find it right now but this is roughly what it said.

During the flare an updraft caused the a/c to float past the end of the TDZ, G/A initiated with positive climb and gear up however speed then rapidly decayed below the top of the amber band due windshear. Windshear procedure was 'done' however the a/c then crash landed. Mayday declared at this stage and evacuation initiated.

Last edited by Paracab; 10th Aug 2016 at 21:22. Reason: spillingmistook
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Old 10th Aug 2016, 20:53
  #766 (permalink)  
 
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Originally Posted by Paracab View Post
Just read a basic report supposedly from one of the pilots on social media... please don't shoot the messenger. Was a few mins ago on twitter and I can't find it right now but this is roughly what it said.

During the flare an updraft caused the a/c to float past the end of the TDZ, G/A initiated with positive climb and gear up however speed then rapidly below the top of the amber band due windshear. Windshear procedure was 'done' however the a/c then crash landed. Mayday declared at this stage and evacucation initiated.
Well I don't see a 777 with both engine operating normally not get out of a windshear, especially being nowhere near MTOW. There muss be more to the story...
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Old 10th Aug 2016, 22:11
  #767 (permalink)  
 
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Perhaps the clue about the state of the landing gear is the lack of damage to the bottom of the engine?
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Old 10th Aug 2016, 22:20
  #768 (permalink)  
 
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Perhaps the clue about the state of the landing gear is the lack of damage to the bottom of the engine?
Which one?? The one we see on the left in passengers video whilst exiting that is burning on its bottom from having served as a landing skid.

or the one on the right that got run over and ended up on top of the rh wing?
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Old 10th Aug 2016, 22:25
  #769 (permalink)  
 
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Originally Posted by lomapaseo View Post
Which one?? The one we see on the left in passengers video whilst exiting that is burning on its bottom from having served as a landing skid.

or the one on the right that got run over and ended up on top of the rh wing?
Loma, I think he is referring to the left hand engine. If the wings were a bit "right wing down" and there was some drift to the right as it came down, depending on a bunch of factors there might be enough side load for the right gear to fail since it was coming down harder than usual ... as the right absorbs energy, and the RH engine does, and the right wing does .. maybe the LH MLG doesn't fail so the LH engine doesn't get as much punishment as the right?

This is all maybe and guessing, and I do not have enough pictures to look at as the plane slid down the runway to get a sense of its "flat" or "tilted" attitude to support that idea.
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Old 10th Aug 2016, 23:07
  #770 (permalink)  

 
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A familiar mistake ex Airbus pilots who have converted to Boeings make is to firewall the throttles forgetting to press the TOGA switch in the event of a go around. The result is the aircraft accelerates down an ILS if the autopilot is still engaged. I wonder if this could have been a factor here.
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Old 10th Aug 2016, 23:11
  #771 (permalink)  
 
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But presumably they would have been pulling back which would disconnect the autopilot (if you're fighting it) and this assumes Dubai has a backbeam.
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Old 10th Aug 2016, 23:17
  #772 (permalink)  
 
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Originally Posted by LIMA OR ALPHA JUNK View Post
A familiar mistake ex Airbus pilots who have converted to Boeings make is to firewall the throttles forgetting to press the TOGA switch in the event of a go around. The result is the aircraft accelerates down an ILS if the autopilot is still engaged. I wonder if this could have been a factor here.
PF is Boeing pilot not converted Airbus
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Old 10th Aug 2016, 23:22
  #773 (permalink)  

 
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Thanks - I did wonder if he had converted off Airbus but evidently not then. The Bailey article is probably the most plausible explanation then.
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Old 10th Aug 2016, 23:52
  #774 (permalink)  
 
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As a mere SLF, wondering if there are definite SOPs about deciding exactly what constitutes "positive rate/climb" before it can be called out? Does it have to be an ascent that lasts a certain amount of time and/or at a certain min rate of vertical speed for example, i.e. Not just a brief moment of lift such as off a bounce ?

Many thanks for this most informative forum.
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Old 10th Aug 2016, 23:55
  #775 (permalink)  
 
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FWIW IMHO If gear was transition between up OR down and hydraulics are lost, gravity will normally lower the gear ( free fall ) if in flight. It may well be that the position in photo was the result of picking up the wing thus allowing the gear to fall even more since it was unlocked when fit hit the shan and plane came to rest .
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Old 11th Aug 2016, 00:34
  #776 (permalink)  
 
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Lack of understanding of Automation and how it behaves in a non normal situation is what has caused the recent accidents including the 777 accident in Dubai.

I can't agree with this statement. This is a contributory factor for sure, but the cause goes back further than that.


If you are flying the aircraft as every PF should be - that is monitoring attitude, airspeed, altitude, vertical speed & thrust - and only using the autoflight system as one of a number of aids to assist in that process, there would not be an issue as long as pilots were competent & adequately trained.


The problem is that in recent times pilots have started to abdicate their responsibility to the automatics & have ceased to monitor most, if not all, the basics. And the first two to go are airspeed & thrust. I have seen it many times over the years. Pilots tell the A/T system what they want via the MCP & then just expect the system to react correctly, without confirming and/or backing up to ensure that that is the case.


The bottom line is that it wouldn't matter if they didn't completely understand the automatics, as long as the continued to fly the aircraft at all times & remove or override the automatics manually if required. Of course it would be preferable if pilots did fully understand the automatic systems on the aircraft, but lack of understanding is not where the primary cause of these accidents lies.


It seems to me that some have become uncomfortable with the standard of their basic flying skills & have become reliant on the automatics to cover their shortfalls. The reasons for this are varied, but a number of accidents over the years has highlighted this problem. The Kenyan & Ethiopian B737 accidents come to mind, along with the Asiana B77 accident. Coupled with this, is the fact that two engine go-arounds are perhaps the worse performed exercises in the industry. This is common knowledge in the checking circles I have moved in, in the past.


The go-around procedure that has been used on all the Boeings I have flown, in all the airlines I have worked for, has always been the same.


1. PF calls "Going around - Flap 20 (B777)", hits TOGA & ensures that the thrust levers go forward - way forward, while pitching to the target pitch attitude or ensuring that the A/P is responding correctly
2. PNF selects the flap, verifies & calls "Positive climb(or rate)"
3. PF calls "Gear up - check thrust"
4. PNF selects gear up, checks that go-around thrust is set & calls "Thrust set".


Seems simple, but it gets messed up all the time in the sim & even in the aircraft. In this case it looks like the aircraft has settled back onto the runway with the gear in transit. It will be interesting to read the final report to see if anything was missed & whether or not environmental factors had a role to play in the outcome.

Last edited by Oakape; 11th Aug 2016 at 01:11.
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Old 11th Aug 2016, 01:02
  #777 (permalink)  
 
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Originally Posted by LIMA OR ALPHA JUNK View Post
The Bailey article is probably the most plausible explanation then.
Close enough about integration of humans and automatics...I think investigation will give more then just "rumors"
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Old 11th Aug 2016, 01:21
  #778 (permalink)  
 
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Originally Posted by Oakape View Post
1. PF calls "Going around - Flap 20 (B777)", hits TOGA & ensures that the thrust levers go forward - way forward, while pitching to the target pitch attitude or ensuring that the A/P is responding correctly
2. PNF selects the flap, verifies & calls "Positive climb(or rate)"
3. PF calls "Gear up - check thrust
4. PNF selects gear up, checks that go-around thrust is set & calls "Thrust set".
... and most probably they did all above, probably real trap was:
1. PF hand flying increasing workload for all
2. A/C touched rwy and rules of TOGA have changed
3. OAT very high, 996mb, tail wind
4. Additional drag of LDG gear in transition
.... you need to be a superman to save the day
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Old 11th Aug 2016, 01:30
  #779 (permalink)  
 
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Hearing the recordings, the tower controller was acting normal, while flights in front of EK521 were going around. For windshear? Why did tower not inform all approaching aircraft, instead the only thing he said was the high speed exit to expect. Apologies if this has already been discussed in the long topic.
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Old 11th Aug 2016, 01:44
  #780 (permalink)  
 
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The B777 has been flying for nearly 19 years. And therefore could be regarded as a fairly mature design. It's safety record is excellent, with few incidents directly attributable to the aircraft. There is a huge knowledge base out there of thousands of pilots with years of experience operating all over the world.

Surely by now any inherent faults would be known about and either corrected, or the pilots trained to deal with them.

Airbus had a number of incidents when the A320 was first introduced but that type was radically different from anything previously flown. Some design changes were made and training improved as operational experience grew. Today it's safety record is excellent, especially given that it operates multiple sectors per day into secondary airports with less experienced crews. The B737 also has an excellent record in the same operational environment as the A320 but relied on older, tried and proven technology rather than cutting edge new design.

When the final report comes out it's likely to show that once again the weak link in the safety chain is the human interface with the automation together with the age old "if it can go wrong, it will go wrong."
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