Go Back  PPRuNe Forums > Flight Deck Forums > Rumours & News
Reload this Page >

TransAsia in the water?

Rumours & News Reporting Points that may affect our jobs or lives as professional pilots. Also, items that may be of interest to professional pilots.

TransAsia in the water?

Old 6th Feb 2015, 23:37
  #341 (permalink)  
 
Join Date: Nov 2000
Location: Canada
Posts: 513
If the story is accurate, it is an amazing route to take.

TransAsia says all its 71 ATR aircraft pilots face skills test following crash
PUBLISHED ON FEB 6, 2015 10:26 PM Dec 6, 2014. Taiwan's TransAsia Airways said Friday all its 71 ATR pilots will have to take a flight skills test following its second deadly accident in seven months. -- PHOTO: EPA

TAIPEI (AFP) - Taiwan's TransAsia Airways said Friday all its 71 ATR pilots will have to take a flight skills test following its second deadly accident in seven months.

In a statement, the airline said "71 pilots on its fleet of 10 ATR planes will be required to do a test by the Civil Aeronautics Administration and a professional unit to make sure they are all qualified on their jobs."

- See more at: TransAsia says all its 71 ATR aircraft pilots face skills test following crash - East Asia News & Top Stories - The Straits Times
Longtimer is offline  
Old 7th Feb 2015, 00:22
  #342 (permalink)  
 
Join Date: Dec 2000
Location: On the equator
Posts: 1,292
Originally Posted by Longtimer View Post

In a statement, the airline said "71 pilots on its fleet of 10 ATR planes will be required to do a test by the Civil Aeronautics Administration and a professional unit to make sure they are all qualified on their jobs."
Errm, excuse me, but shouldn't that have been done before they were employed by the airline? A bit too late once they're on the line to find later that they're not "qualified on their jobs".
training wheels is offline  
Old 7th Feb 2015, 00:31
  #343 (permalink)  
 
Join Date: Dec 2000
Location: On the equator
Posts: 1,292
Originally Posted by avionimc View Post
#327

With PT6 engines, in case of suspected engine problems, both power levers stay or go to TOGA [or appropriate] power.

Why would "one" throttle be retarded in an ATR?
It's a memory item action for securing a failed engine, but NOT a fully working engine. The power lever (they're not called throttles btw) is brought to Flight ldle and Condition Level to feather and then to fuel cut-off of the AFFECTED engine.

It's obvious they mis-identified the failed engine and that there was poor CRM, because before making such actions, the PNF who is performing the actions needs to confirm with the PF that the Power Lever and Condition Lever is that of the affected engine, whilst the PF continues to fly the aircraft.
training wheels is offline  
Old 7th Feb 2015, 00:41
  #344 (permalink)  
 
Join Date: Mar 2011
Location: Around
Posts: 49
#327

With PT6 engines, in case of suspected engine problems, both power levers stay or go to TOGA [or appropriate] power.

Why would "one" throttle be retarded in an ATR?
Because it's not a PT6 . The ATR is a very deifferent beast compared to most TP in its operation.

Also be aware it's standard ATR procedure (right or wrong) that PF manipulates the PL during the memo items. From there the PNF takes over and does the CL and Bleed.
BO0M is offline  
Old 7th Feb 2015, 00:41
  #345 (permalink)  
 
Join Date: Feb 2015
Location: Florida
Posts: 4
Well, if they're check airmen then whatever they did was the right procedure.
KenM is offline  
Old 7th Feb 2015, 01:04
  #346 (permalink)  
 
Join Date: Dec 2004
Location: In Hyperspace...
Posts: 395
Hello Ka6crpe,

I've based my supposition primarily on the data published from the FDR trace and the FlightRadar24 ADS-B returns, and they seem to roughly correlate. I've only used what I've seen in the videos / stills as secondary data to confirm or discard thoughts based on the other data.

Whilst I've no doubt that the final few seconds involved a deepening stall culminating in wing drop, I don't believe it was flown from TOD in stalled conditions - and I theorised as much yesterday, before the FDR trace was released.

Did you take perspective / parallax aspects into account when you did your visual analysis, and what did you use as your reference point in the vids to derive the angles from? I don't mean to dismiss your thoughts at all - you could easily be right and I wrong, in a paucity of a complete data set.

Happy to discuss...
TheInquisitor is offline  
Old 7th Feb 2015, 01:05
  #347 (permalink)  
 
Join Date: Feb 2015
Location: yankton, sd
Posts: 290
boom...how is this engine different? I mean I understand the stages, but in operation, if engine 1 is producing thrust, and engine 2 has something wrong, why touch power lever on 1?

I would protect it from moving. I think most of us would.

Certainly if you were below Vmca, you might retard #1, but unless there was a good reason, why touch it?
skyhighfallguy is offline  
Old 7th Feb 2015, 01:28
  #348 (permalink)  
 
Join Date: Jul 2013
Location: New Zealand
Age: 67
Posts: 74
TheInquisitor, OK I see where we are differing. I based my fully stalled comment on the video in post 326, which is in the last few seconds of flight from building height and lower, not from TOD. I thought I had made that clear when I referenced "...in that video", but maybe I did leave too much room for interetation.

To get the angle of descent I took the point at which the top of the cockpit crossed the horizon to where it crossed the building imediately in front (at the 26 second mark). It is not quite square on but is certainly less than 30 degrees of parallax, so the error would not be too great. I allowed a full 30 degrees in my estimate, hence the comment that the actual descent may have been at a greater angle than my estimated 14 degrees.

That video from the dash cam in post #8 appears to pick up the aircraft as it passes that same building and is 5 seconds to impact.
Ka6crpe is offline  
Old 7th Feb 2015, 01:30
  #349 (permalink)  
 
Join Date: Sep 1998
Location: The Swan Downunder
Posts: 575
This is looking like second stage power turbine failure to me, itís easy to miss identify an engine failure in this condition and not something we train for since simulators generally donít accommodate this condition.
How we monitor the condition of this turbine is when takeoff torque is within 2% of target torque for takeoff check, assuming this was within allowable limits at takeoff then as the second stage turbine degrades the torque will fall away until it drops to the auto feather trigger value, usually around 50%.
This is where the confusion starts, the gas generator is still functioning normally the feathered propeller is still being driven by the seriously degraded engine, you would expect to see a prop rpm in the order of 30 to 40 percent and a torque value quite possibly exceeding 100%, with no engine failure indications apparent, if all your looking at is the torque gauges, left at say around 98% right engine more than that and an airplane performing as it should on one engine, one can begin to see if we are honest how easily it is to misidentify an underperforming engine, particularly if you.ve never seen this condition before.
Xeptu is offline  
Old 7th Feb 2015, 01:38
  #350 (permalink)  
ZFT
N4790P
 
Join Date: Jun 2002
Location: Asia
Age: 70
Posts: 2,053
Quote:
Originally Posted by Longtimer

In a statement, the airline said "71 pilots on its fleet of 10 ATR planes will be required to do a test by the Civil Aeronautics Administration and a professional unit to make sure they are all qualified on their jobs."


Errm, excuse me, but shouldn't that have been done before they were employed by the airline? A bit too late once they're on the line to find later that they're not "qualified on their jobs".
IF this crew did misidentify the engine then the airline is at least recognising there is a significant training issue to be addressed.

Somehow, I think they may be more to it then this though and they shouldn't be crucified just yet.

(I don't know if the July 2014 accident report has been published yet but both the airline and the Taiwanese regulator will know that it was a totally avoidable accident and that may well have a bearing on the (training and checking) recommendations from this accident too)
ZFT is online now  
Old 7th Feb 2015, 01:39
  #351 (permalink)  
 
Join Date: Dec 2004
Location: In Hyperspace...
Posts: 395
Ka6crpe - Agreed, within those bounds - if one looks again at the 'height' traces both on FDR and FR24, you can see a significant 'dip' towards the end - which may correlate with the portion of the video you analysed?

Useful, I feel, for 'end-game' analysis - but maybe less useful in determining causality?

Perhaps it's an indication of the human tendency to concentrate on the 'spectacular' (which the videos representing a few seconds certainly were!) - as opposed to the relatively dull linear analysis of some 2-3 mins worth of flight...

Whatever the conclusion, I have to say that in 25 years as an aviator, I have never before seen such close-up and detailed video evidence, followed by such a rapid release of FDR data - on top of the relatively new phenomenon of ADS-B derived traces, too...

I'm not sure yet whether it's a good or bad thing that we are somehow able to be sitting here, only 3 days after an accident, doing an 'amateur' (albeit as interested and deeply-connected professionals) analysis of an accident sequence.... to my knowledge, it is unprecedented.
TheInquisitor is offline  
Old 7th Feb 2015, 01:51
  #352 (permalink)  
 
Join Date: Dec 2004
Location: In Hyperspace...
Posts: 395
Xeptu,

Thanks for the in-depth tech info.

Can you see anything from the FDR trace that indicates this as a possibility? From my (admittedly, non-type-expert) analysis, I can see little wrong with either engine prior to the #2 autofeather.

...which leads us back to the first of my '2 mysteries' postulation above... Why did the #2 autofeather, and what triggered the 'flameout' detection when the engine appears not to have flamed out at all?

I would also be very interested to know what type / company SOPs are with regards to a/p engagement - were they likely to be hand-flying, or relying on the automatics?

I ask because from experience, I cannot fathom how a misdiagnosis of which engine has failed can occur in a twin TP that is being hand-flown.
TheInquisitor is offline  
Old 7th Feb 2015, 01:52
  #353 (permalink)  
 
Join Date: May 2001
Location: NZ
Posts: 656
BO0M,

ATR SOP is for the PM/NFP to action all checklist items, upon confirmation from the PF, whose primary job is aircraft flightpath maintenance i.e. Flying the plane
Sqwark2000 is offline  
Old 7th Feb 2015, 02:30
  #354 (permalink)  
 
Join Date: Mar 2011
Location: Around
Posts: 49
BO0M,

ATR SOP is for the PM/NFP to action all checklist items, upon confirmation from the PF, whose primary job is aircraft flightpath maintenance i.e. Flying the plane
Sorry to say this S2K but you have this one wrong. Yes the NZ operation has that SOP which was gained via a NTO to ATR many moons ago. However the FCTM that ATC produce to operators world wide has PF controlling the PL in the flame out situation.

Upside, count yourself lucky you have good SOPs.
BO0M is offline  
Old 7th Feb 2015, 02:31
  #355 (permalink)  
 
Join Date: Oct 2008
Location: NY
Posts: 38
Fly the plane. Don't touch ANYTHING! Take a breath, count a few, and take it from there....

Yanking levers and all that, well, we see how that worked out....
OD100 is offline  
Old 7th Feb 2015, 04:26
  #356 (permalink)  
 
Join Date: Jul 2008
Location: USA
Posts: 21
@olasek, Thanks for posting the data.

Last edited by noalign; 7th Feb 2015 at 10:48. Reason: I'll just watch.
noalign is offline  
Old 7th Feb 2015, 04:49
  #357 (permalink)  
 
Join Date: Nov 2005
Location: JAKARTA
Posts: 16
prior to check pilot in simulator TAIWAN DCA should check FDTL. in transasia
cris95123 is offline  
Old 7th Feb 2015, 05:49
  #358 (permalink)  
 
Join Date: Jun 2006
Location: Canada
Posts: 15
Dead foot/dead engine

Curious. And forgive if this comes across over-simplified (I've never flown a twin bigger than a 402).
When the right engine went to auto-feather, would there not be pronounced yaw to the right, resulting in left rudder input, and a dead-foot/dead engine clue to guide correct identification and shutdown?
Or on the ATR is the yaw not that pronounced?
Many thanks, all.
avroarrow is offline  
Old 7th Feb 2015, 05:52
  #359 (permalink)  
 
Join Date: Jul 2013
Location: bangko
Posts: 20
Oooops

Its clear they shut down the wrong engine

Its clear they realized this late in the gane and turned the fuel lever on and started engine 1. It did spool up, but too late
skippybangkok is offline  
Old 7th Feb 2015, 06:24
  #360 (permalink)  
 
Join Date: Feb 2015
Location: Front Left
Posts: 19
I think its is pretty clear that the crew shut down the wrong engine, #1.

But what happened to ENG #2?

Unless there are some timing issues (Sample rate) on the DFDR traces released it doesn't make any sense.

The triggering condition for ATPCS is one TQ < 18%. But according to the DFDR the engine was already feathered by the time TQ #2 dropped below 18%, that sould rule out an standard ATPCS sequence, unless there are timing issues with DFDR data.

The only uncommanded feathering of a propeller on an ATR I have head about involved the incorrect installation of the prop itself, in which the mechanics omitted installing the stepped pin, which after a few flights resulting in loss of oil pressure to the prop which then by design will feather.

But that would initially lead to a massive over torque on affected engine, and even if the DFDR data does indicate an initial TQ 2 increase, its very hard to tell from the low res scale provided.
Royale is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.