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Asiana 777 crash at KSFO

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Asiana 777 crash at KSFO

Old 12th Jul 2013, 17:32
  #61 (permalink)  
 
Join Date: Apr 1999
Location: South of North
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Why would EK have to react to this accident?? They have been VERY proactive on the stabilized criteria front and, by and large, our crews do an excellent job!!

While you can't say it will never happen I believe the VAST majority of EK crews would have went around at 1000' but certainly by 500' when this crew was laterally off as well as vertically off (based on what the NTSB has said so far).

The comments regarding CRM are right on though!! I hope the cost cutting does not bring in non pilot (or non active pilot) instructors. The EK CRM course is the absolute best CRM I have seen and, in my opinion, probably an industry leader. ND, who runs it, is brilliant in his job and ,I hope, is not being hamstrung by new leadership.

This recent cost cutting is worrisome. EK has built a good system which they seem to be dismantling now.

The flying hour increase was the start of the narrow minded, short term cost measures.
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Old 13th Jul 2013, 09:11
  #62 (permalink)  
 
Join Date: Jun 2001
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Hmmmm....Sum Dum Fuk at NTSB is probably joining the ranks of the unemployed over that one...totally unacceptable...how embarrassing
Apparently the NTSB "Official" who confirmed the names was an unpaid intern!

You get what you pay for....
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Old 13th Jul 2013, 09:43
  #63 (permalink)  
 
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NTSB completes work at Asiana 777 crash site; no systems anomalies found

“During the approach, there were statements made in the cockpit, first about being over the glide path, then about being on the glide path, then about being under the glide path, Hersman explained, citing the CVR. One pilot has told investigators he realized the aircraft was too low at about 500 feet, or about 34 seconds to impact with SFO’s sea wall."

But even as the pilots were aware of being too high and then too low, they did not realize the 777’s speed had dropped from a target speed of 137 knots to 103 knots until seconds before impact, according to NTSB.

NTSB completes work at Asiana 777 crash site; no systems anomalies found | Safety content from ATWOnline
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Old 13th Jul 2013, 14:31
  #64 (permalink)  
 
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http://m.youtube.com/watch?feature=related&v=JhoAfgYhhs0
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Old 13th Jul 2013, 14:48
  #65 (permalink)  
 
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LMAO!!!

Capt. Sum Ting Wong


F***king Brillant!!!!!
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Old 14th Jul 2013, 12:55
  #66 (permalink)  
 
Join Date: Mar 2006
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Wizofoz:

Can you help me out here...imagine I am downwind descending in FLCH HOLD and ATC says “y'all make a visual approach now, follow xx”. I set 1000' on the MCP, disconnect the autopilot and perform one of my exemplary visual approaches. F/D off but PM leaves his on. We set a higher alt on the MCP when stabilised.
Will the autothrottle stay in HOLD?

PS -sorry guys they had 4 pilots because the trainee has to fly with a TRI, normally it would be 3 out to 12:30.
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Old 14th Jul 2013, 13:34
  #67 (permalink)  
 
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HPSOV L,

Yes, your speed will decay all the way into the amber band and you will eventually stall unless of course you are not automagic dependent, no AT wakeup, is my understanding.
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Old 14th Jul 2013, 13:41
  #68 (permalink)  
 
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feds correct- no A/T wakeup in that scenario- but further I think the speculation is the Asiana crew set the MCP alt to zero.
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Old 14th Jul 2013, 16:12
  #69 (permalink)  
 
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Crikey, they should get that fixed or put a sign up before someone has a nasty accident...
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Old 14th Jul 2013, 20:24
  #70 (permalink)  
 
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no A/T wakeup in that scenario- but further I think the speculation is the Asiana crew set the MCP alt to zero.
Minimum Maneuvering Speed
Indicates maneuver speed margin to stick shaker or low speed buffet. Top of the bar is the airspeed that provides:
1.3g maneuver capability to stick shaker with flaps down

EICAS message AIRSPEED LOW
Level: Caution
Aural: Beeper
Message Logic: Airspeed is below Minimum Maneuvering Speed

The autothrottle can support stall protection if armed and not activated. If speed decreases to near stick shaker activation, the autothrottle automatically activates in the appropriate mode (SPD or THR REF) and advances thrust to maintain minimum maneuvering speed (approximately the top of the amber band) or the speed set in the mode control panel speed window, whichever is greater.
Note: When the pitch mode is FLCH or TOGA, or the airplane is below 400 feet above the airport on takeoff, or below 100 feet radio altitude on approach, the autothrottle will not automatically activate.

The A/T ARM Switches looks like they were in OFF. Or the airplane went below Minimum Maneuvering Speed below 100 ft RA. But still AIRSPEED LOW + beeper + Caution at 100ft RA ...
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Old 14th Jul 2013, 20:35
  #71 (permalink)  
 
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Will the autothrottle stay in HOLD?
I will exclude the HOLD FLCH SPD unless the crew had a diabolic willing to set the MCP Speed below VREF30+10 (or+5). When in HOLD and the speed reaches the MCP speed automatically changes in THR to maintain the selected speed.
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Old 14th Jul 2013, 21:11
  #72 (permalink)  
 
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When in HOLD and the speed reaches the MCP speed automatically changes in THR to maintain the selected speed.
No it absolutely does not.


IF auto-throttle wake-up engages, it puts the A/T into SPD mode, and either targets a speed just outside the low speed amber band if the selected speed is INSIDE the amber band, OR targets the bugged speed if the bug is OUTSIDE the amber band.

BUT- Auto-throttle wake-up does NOT function when the A/T is in HOLD (Typically when climbing or descending in FLCH or VNAV SPD)

THAT is consistent with what you quoted here-

Note: When the pitch mode is FLCH or TOGA, or the airplane is below 400 feet above the airport on take-off, or below 100 feet radio altitude on approach, the auto-throttle will not automatically activate.
The NTSB has confirmed the A/T switches were in "ARM"- so being in FLCH and thus with A/T in "Hold" seems a likely scenario.

Yes. they would have gotten an "Airspeed Low" EICAS- but seem to have been slow to respond to it.

Last edited by Wizofoz; 15th Jul 2013 at 06:16.
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Old 15th Jul 2013, 03:54
  #73 (permalink)  
 
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'Tis true someone needs to review their FCOM...

"FOR A START THR does not act to maintain a speed- it sets the power to whatever is the currently annunciated maximum thrust on the Thrust Rating Panel"

Wrong.

It would be "THR REF" that does that. "THR" applies power as required by the current mode - you have no idea what amount that will be.

Last edited by Dropp the Pilot; 15th Jul 2013 at 03:55.
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Old 15th Jul 2013, 04:21
  #74 (permalink)  
 
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I'm still a little alarmed that the concept of this trap had never occured to me.

1. I deduce that talk of autothrottle wakeup in HOLD mode is perhaps misleading as it is already 'awake'- ie: it is already activated in HOLD mode. Maybe this is the crux of why there is no stall protection logic.


2. Could the accident aircraft have been in VNAV SPD with 0' or a MAA set on the MCP?

"Note: During a descent in VNAV SPD, the autothrottle may activate in HOLD mode and will not support stall protection"

Last edited by HPSOV L; 15th Jul 2013 at 04:49.
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Old 15th Jul 2013, 04:52
  #75 (permalink)  
 
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I'm still a little alarmed that the concept of this trap had never occured to me.

1. I deduce that talk of autothrottle wakeup in HOLD mode is perhaps misleading as it is already 'awake'- ie: it is already activated in HOLD mode. Maybe this is the crux of why there is no stall protection logic.


2. Could the accident aircraft have been in VNAV SPD with 0' or a MAA set on the MCP?

"Note: During a descent in VNAV SPD, the autothrottle may activate in HOLD mode and will not support stall protection"


3. Am I correct in saying that if there is no altitude set on the MCP for FLCH to capture you effectively have no autothrottle? And that the only way to regain the autothrottle is to change modes or turn the f/ds off, whereby the autothrottle mode changes to SPD?
The sad thing is, the A/T is virtually identical the 757/767, and almost all the little traps existed when I flew that as well. All these traps were demonstrated when I did my 757 course 12 years ago, by experienced trainers with many many years of TRI/TRE experience.
Sadly inspite of the inevitable well meaning protestations of a few, my 777 course lacked the depth of understanding to even delve close to the depth I encountered previously, the net result being a lower level of systems knowledge.
I pity the guys who continue to baffle themselves in the hold using VNAV who scratch their heads when the thing decides to climb....
It must be a real shock for an aeerboos convert.
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Old 15th Jul 2013, 06:15
  #76 (permalink)  
 
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"FOR A START THR does not act to maintain a speed- it sets the power to whatever is the currently annunciated maximum thrust on the Thrust Rating Panel"

Wrong.

It would be "THR REF" that does that. "THR" applies power as required by the current mode - you have no idea what amount that will be.
Quite correct- thanks for the pick up.
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Old 15th Jul 2013, 07:57
  #77 (permalink)  
 
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You guys who weren't shown this 'feature', did you do your training with EK? I'm curious because I was definitely shown during initial at least twice, and I've seen it again doing manual handling. I bet we'll all be seeing it in the near future. For what it's worth, the TRE told me 'If the FMA says HOLD, that means hold the thrust levers with your hand'. I suppose it's a little geeky, but I do just religiously. My 2 dirhams........
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Old 15th Jul 2013, 09:36
  #78 (permalink)  
 
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It is most definately was a part of the initial TR at EK (8yrs ago), and it still is!
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Old 15th Jul 2013, 11:44
  #79 (permalink)  
 
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I spent 9 joyous years at EK and, with respect, I don't recall it being pointed out to me.
Lets be clear we are talking about a rare but conceivable situation where you have transitioned to a manual approach with a certain MCP and F/D configuration. In this particular case you may intuitively incorrectly assume you are in SPD mode and/or that stall protection is available.
Not to confused with understanding what FLCH HOLD means.
No comments please about FMA monitoring etc! Not the point...
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Old 15th Jul 2013, 12:07
  #80 (permalink)  
 
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Not to confused with understanding what FLCH HOLD means.
No comments please about FMA monitoring etc! Not the point...
I respectfully disagree. It doesn't matter what MCP or F/D mode you are in. If the first word on the FMA is 'HOLD', the A/T is on but it will not 'wake up' and it offers no stall protection. There are a few different modes that will cause A/T HOLD and none are:
rare but conceivable
Maybe I'm missing your point?
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