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Asiana flight crash at San Francisco

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Asiana flight crash at San Francisco

Old 7th Jul 2013, 08:07
  #321 (permalink)  
 
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A1anx...
Who are the examiners that are allowing this to happen?
Seems to me that if you can't 'fly the plane' and not the computer, maybe you should get a desk job at Microsoft...

Last edited by Latte tester; 7th Jul 2013 at 08:08.
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Old 7th Jul 2013, 08:08
  #322 (permalink)  
 
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777 Autothrottle wake up

With the autothrottle armed, the autothrottle automatically activates if no autopilot or F/D is active or an autopilot or F/D is in VNAV XXX, ALT, V/S, or G/S, and:

• speed less than an FMC calculated value for one second

• thrust below reference thrust

• airplane altitude above 100 feet RA on approach, or airplane barometric altitude 400 feet above airport on takeoff

The autothrottle can support stall protection when 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 speed window, whichever is greater. The EICAS message AIRSPEED LOW displays.

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.

Note: During a descent in VNAV SPD, the autothrottle may activate in HOLD mode and will not support stall protection.
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Old 7th Jul 2013, 08:11
  #323 (permalink)  
 
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From my experience the 777 A/T is very good. Speed decay would not occur like this (viewing the speed alt data posted earlier).
...Unless, as has been mentioned above, the A/T is in HOLD mode, in which case A/T Wake Up is not active.

As there was no ILS, they may have been descending in FLCH or VNAV SPD, conditioned by a thousand ILS and RNAV approaches to expect the A/T to take care of the speed, for it to just stay at idle.

I've had students come to their upgrade with thousands of hours on the type, unaware of this "feature' of the AFDS.

ETA- Crossed posts with Douglas, who's quote summarizes it very well.

Last edited by Wizofoz; 7th Jul 2013 at 08:13.
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Old 7th Jul 2013, 08:13
  #324 (permalink)  
 
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Do you have a reference for that?
It is similar in Australia, no visual slope guidance means no commercial jets, however you can get a dispensation from CASA to be able to operate to an aerodrome with no slope guidance with various restrictions.
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Old 7th Jul 2013, 08:22
  #325 (permalink)  
 
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Australian RPT Regs for slope guidance (in place for 30+ years):

5.3 Unless otherwise approved in writing by CASA and subject to paragraph 5.4, an operator must not permit turbo-jet aeroplanes to use runways that are not equipped with electronic or visual approach slope guidance.
5.4 Paragraph 5.3 does not apply to runways at nominated alternate aerodromes.
There are dispensations but only for a very limited timeframe, and the captain has to be specifically approved.
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Old 7th Jul 2013, 08:23
  #326 (permalink)  
 
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Yep you are right Hoggsnortrupert

The 3nm/1000 ft works just fine - but only to the DME position.
If you can set the rwy threshold as a fix, then you can use the miles to go to that fix using 3nm/1000ft - of course corrected for height above MSL which was zero in this case !!

Last edited by Flingwing47; 7th Jul 2013 at 08:25. Reason: title
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Old 7th Jul 2013, 08:31
  #327 (permalink)  
 
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Are ALL western pilots RACIST or just PPRUNE?

I'm appalled at the racist comments in this thread several of which blame the crash on 'Asian' pilots.

If generalised racist comments about Asians are valid then entirely 'valid' observations can be made about Americans and Australians.

Could it be possibly relevant that:

* A fatigued crew has flown half way round the world
* SFO ATC changes the runway at the last minute
* The crew has to sidestep across on to a visual approach
* The new visual approach has a displaced threshold, no PAPI, no GS

But according to you racists it's entirely their fault because their eyes are the wrong shape...

Time will tell
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Old 7th Jul 2013, 08:33
  #328 (permalink)  
 
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ttowne 1267. Good call on the fuselage ignition source being friction, but if you look at the #2 engine, there is a lot of scorching on the fuselage around the ehaust and it is still attached by a solid-looking umbilical. If it was still getting fuel..... Well we saw with AF in Honolulu and more recently QF in SIN how difficult they are to stop (of which I normally strongly approve).

I've flown many times into SFO on 747 2/3/400, from the North, normally the Bay approach to RH visual cleared visual relatively high, and if you are not ready for getting into the descent fast, it's very easy to get into the high rate/low thrust area close in. 300' per mile has always worked for me and we were also taught on all the A/C I have flown (F27 and up) to know your stabilised 3' ROD on final.

Some good stuff on this post, the inspectors shoul be able to get the recorders, so all will be revealed.
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Old 7th Jul 2013, 08:36
  #329 (permalink)  
 
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re: A/T wakeup

Sounds like they may have been in the <100' RA inhibit zone when the speed decayed sufficient for activation – will the system 'kick in' if the RA subsequently goes back up above 100' threshold (as it appears happened here)?
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Old 7th Jul 2013, 08:37
  #330 (permalink)  
 
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Asiana flight crash at San Francisco

Suninmyeyes has probably got it close. It seems fairly obvious the aircraft got low and slow, impacting with a high angle of attack, the question of course is why that should happen on such a benign day.

My guess is that the crew were relying on the A/T to control their speed and failed to notice it wasn't . I know there will be howls,especially from those gents who flew older stuff about poor flying skills but I think that those of us who are completely honest with ourselves and fly modern aircraft like the 777 and the Airbus would admit that scanning the engine indications has almost dropped out of the scan pattern and that speed is perhaps not as well scanned as it should be.

Not for one second saying this is how it SHOULD be just being realistic. For most operators the crews are forbidden from practising A/T off approaches ( despite a U/S A/T not being a no dispatch item).

So my guess would be that the A/T was in a mode which did not auto wake up or had dropped out or been disconnected and the crew failed to notice the speed decay. A cognitive failure could also cause someone to press the A/T disconnect on the side of the thrust lever rather than the TOGA on the front of the thrust lever.
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Old 7th Jul 2013, 08:39
  #331 (permalink)  
 
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Flingwing47, it is easy enough to add or subtract altitude to account for the difference in distance between the runway threshold and the DME. A very basic example is if the DME is 0.5 NM beyond the threshold then you should use DME distance x 300 - 150'. You can also get anal about threshold crossing heights and touchdown points but given it is just a rough guide I don't see that as being necessary!
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Old 7th Jul 2013, 08:40
  #332 (permalink)  
 
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Similar rule in NZ (from NZ CAR Part 121):

(b) A holder of an air operator certificate must ensure that an aeroplane performing an air operation under the authority of the holder's certificate does not use an aerodrome for landing or taking-off unless the aerodrome has—

(1) rescue fire equipment that is appropriate to the aeroplane type and is acceptable to the Director; and

(2) for turbojet and turbofan powered aeroplanes, an operating visual approach slope indicator system, except when the aeroplane is performing a precision instrument approach that includes glideslope guidance.
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Old 7th Jul 2013, 08:41
  #333 (permalink)  
 
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Regardless of the final analysis of this crash, it is time that the lack of automated low airspeed warning on approach is addressed. A stick shake at just before the stall is useless on short final. Average line crews have repeatedly proved they are incapable of reliably manually monitoring airspeed when their normal operating mode is ATS or A/T. Modern Nav is quite capable of calculating airspeed and I propose that a suitable audio warning system should be integrated that corelates energy/speed relative to config and approach speed, NOT just Vstall! Just my opinion.
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Old 7th Jul 2013, 08:43
  #334 (permalink)  
 
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Ah get with it !

This flight had a heavy crew! 4 pilots !

Do you honestly think that none of these qualified 4 pilots observed a speed decay and decided not to speak up ?
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Old 7th Jul 2013, 08:43
  #335 (permalink)  
 
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FlightAware data

Does anyone know how accurate the FlightAware data is and where it actually comes from? The last two data points for the accident aircraft have very slow speeds of 109 and 85 knots. Although the altitude still reads as one or two hundred feet I'm wondering if the aircraft was actually on the ground at that point and was sliding to a stop, or if they were airborne and stalling, or if the data just isn't good enough to be drawing any conclusions from it at all.

This is the data I'm talking about: Flight Track Log ? AAR214 ? 06-Jul-2013 ? RKSI / ICN - KSFO ? FlightAware
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Old 7th Jul 2013, 08:44
  #336 (permalink)  
 
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The "40 years in aviation" expert on US MSNBC tonight, ex PanAm captain Tom Bunn has just posted this:

Asiana Crash At San Francisco - National Fear of Flying | Examiner.com

In there he states, "As to height, there is more than adequate guidance; the runway sends ILS signals that show whether or not the plane is on the proper glide path. There is also a visual device to provide proper glide path information."

Seems the Capt needs to check his NOTAMS. Amazing how TV puts on such shallow publicity seekers
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Old 7th Jul 2013, 08:46
  #337 (permalink)  
 
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From the pics on the Reuters site, what looks to be the battered remains of the other engine is well forward of the nose, and on the other side of the runway.
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Old 7th Jul 2013, 08:46
  #338 (permalink)  
 
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no glide slope nor papi?

it is apparent that there was no glide slope nor papi available, in Italy our civil aviation authority has a rule that no landing can be carried by a jet plane without papi especially if the approach is done at night or over featureless surfaces like water...
I think this rule is a legacy of one particular accident :

Alitalia Flight 4128 - Wikipedia, the free encyclopedia
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Old 7th Jul 2013, 08:47
  #339 (permalink)  
 
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A pumps, the Colgan Dash 8 had two qualified crew who failed to note a speed decay and once it was pointed out to them by the stall warning system, failed to do anything constructive to recover. There have also been FOs who have silently sta there watching their captain fly them into the ground. So yeah, I think sometimes you can have a situation where 4 qualified crew could either not notice a speed decay or if they do, not speak up about it. People are unreliable machines.
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Old 7th Jul 2013, 08:55
  #340 (permalink)  
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Asiana CEO quoted as saying there was no 'engine problem'.

EDIT: Correction "No mechanical problems"

Last edited by BOAC; 7th Jul 2013 at 08:56.
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