Turkish airliner crashes at Schiphol
THUNDERTAILED
Joined: Nov 1999
Posts: 340
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From: L200
BOAC - 'The RadAlt was not technically 'u/s' as far as the system goes' - ok - that explains why no disconnect of the A/P, thanks.
But why, if they were doing a single channel approach, would the A/T retard at all because the A/P would never get into FLARE mode? During a single-channel approach would it not maintain command MCP speed until it was disconnected?
But why, if they were doing a single channel approach, would the A/T retard at all because the A/P would never get into FLARE mode? During a single-channel approach would it not maintain command MCP speed until it was disconnected?
Joined: Jan 2006
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From: US
Ballsout - The position you've taken is the exact point many of us rail against. We call those people "Gods of the Glass". Automation is the answer.... Heaven help us if the glass fogs over. The overwhelming majority of approaches I fly or witness(as PM/PNF or jumpseating) are handflown, typically from somewhere around 5-10,000'. A significant percentage of them are also A/T off. All of this in some of the busiest airspace in the world(NYC/ORD/MIA/DFW/LAX). It's not 'gung ho', but your position that basic flying is considered 'gung ho' is scary.
DC-ATE/Rainboe - There's a significant difference when switching from a round dial a/c to tape displays. Once your experience level on the tapes increases it's no big deal, but the transition is tough, especially if it's book training or one simulator session(true story). Airspeed and altitude can't be read at a glance on tapes, unlike round dials.
Target fixation happens fast, and sneaks up on you. That's hopefully where experience pops up and the normal scan is resumed.
DC-ATE/Rainboe - There's a significant difference when switching from a round dial a/c to tape displays. Once your experience level on the tapes increases it's no big deal, but the transition is tough, especially if it's book training or one simulator session(true story). Airspeed and altitude can't be read at a glance on tapes, unlike round dials.
Target fixation happens fast, and sneaks up on you. That's hopefully where experience pops up and the normal scan is resumed.
THUNDERTAILED
Joined: Nov 1999
Posts: 340
Likes: 44
From: L200
BOAC - keep your hair on! I've read the thread, yes, I'm new on the 73 and I'm here to learn, like many here are. I know the A/P and the A/T are two different systems which are able to work in conjunction, I was under the impression that the A/T would only RETARD in this scenario (after G/S capture) if it were a dual channel approach and the flare maneuver had started. Also under the impression that if you left the A/T in until touchdown during a single channel appr it would maintain thrust for MCP speed until 2 secs after t/d after which it would disengage?
Per Ardua ad Astraeus
Joined: Mar 2000
Posts: 18,575
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From: UK
keep your hair on! I've read the thread, yes, I'm new on the 73 and I'm here to learn,
Topslide - perhaps we can negotiate a reduction on 2 wigs....?
THUNDERTAILED
Joined: Nov 1999
Posts: 340
Likes: 44
From: L200
Rainboe go and waste someone else's electrons, you sound like just the sort of captain nobody needs. I'm asking a question here, hopefully someone will be kind enough to answer it.
Of course I don't want to maintain 140 kts after touchdown, I am asking about the system logic. One of the disengagement criteria of the A/T is 2 sec after touchdown if you haven't already disengaged it.
Of course I don't want to maintain 140 kts after touchdown, I am asking about the system logic. One of the disengagement criteria of the A/T is 2 sec after touchdown if you haven't already disengaged it.
Joined: Oct 2002
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From: In my seat
Ballsout,
My God man, the attitude you have concerning flying an airline is exactly why so many low-houred colleges have no clue anymore about stick-and-rudder which is how the aircraft is designed to fly! It is designed to be flown raw-data, any other help is there to make your life easier if you want to, but if you can't fly your machine, then my dear man, you are risking the lives of your passengers and crew every time your main-gear lifts off the runway.
This accident seems more and more a reason to closely look into how far our piloting skills (not computer skills and button-pushing qualities) have decayed and how new-entrants need to be trained. I say again, a manual approach would have avoided this accident.
My God man, the attitude you have concerning flying an airline is exactly why so many low-houred colleges have no clue anymore about stick-and-rudder which is how the aircraft is designed to fly! It is designed to be flown raw-data, any other help is there to make your life easier if you want to, but if you can't fly your machine, then my dear man, you are risking the lives of your passengers and crew every time your main-gear lifts off the runway.
This accident seems more and more a reason to closely look into how far our piloting skills (not computer skills and button-pushing qualities) have decayed and how new-entrants need to be trained. I say again, a manual approach would have avoided this accident.
Per Ardua ad Astraeus
Joined: Mar 2000
Posts: 18,575
Likes: 4
From: UK
AS - serious question. What stage of '737 training' are you at after the L200 time? Depending on your answer, I may need to place your airline on my personal 'nofly' list.
A/T disengages 2 secs after touchdown following RETARD. If it had not retarded, you would be emulating that AB that killed everyone by flying off the end somewhere at 90+kts with power on. (Yet another breakdown in BASIC FLYING SKILLS!!)
I do NOT know if it will:-
a) Try to maintain target speed
b) then disconnect 2 secs after touchdown if it does not RETARD, and I am also NOT interested since I would be FLYING the damn thing and it will not happen on my watch.
A/T disengages 2 secs after touchdown following RETARD. If it had not retarded, you would be emulating that AB that killed everyone by flying off the end somewhere at 90+kts with power on. (Yet another breakdown in BASIC FLYING SKILLS!!)
I do NOT know if it will:-
a) Try to maintain target speed
b) then disconnect 2 secs after touchdown if it does not RETARD, and I am also NOT interested since I would be FLYING the damn thing and it will not happen on my watch.
Joined: Aug 2008
Posts: 1
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From: Netherlands
The question is, why did the crew react soo late, How was there schedule, were they fatigued. Why were previous faults not recorded in Tec/log? It is easy to lay blame to the crew, but one should ask better why they reacted like they did?
A RA fault alone does not lead to a catastrophe like this.
A RA fault alone does not lead to a catastrophe like this.
THUNDERTAILED
Joined: Nov 1999
Posts: 340
Likes: 44
From: L200
BOAC - 2 months. Thanks for answering my question, which you of course knew was hypothetical. As I said before, I was interested in the the system logic and its dependencies. Actually I have Vol 2 open in front of me and read the automatic flight chapter and this thread before asking those questions. I'm often wrong - which is why I ask to learn.
Thanks again.
Thanks again.
Joined: Jul 2008
Posts: 2
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From: PNW
LRRA Fault Detection
Not a pilot (Dad was, now retired) but an RF engineer.
Crew comments aside, I hope the final report provides more focus on the fault detection algorithym used on the LRRA systems and Boeing's requirements for self-fault detection.
Either there was an internal fault with the radio electronics themselves, or a fault developed in the transmission path (antenna & cabling). My understanding is that the RA is calibrated to read zero when on the ground on the gear. If the fault was internal to the electronics, this should have been trivial to code for and detect. Should the fault have delveloped in the 'dumb' portion of the system (cable and antenna) there are easy ways to test and detect that would not interfere with the normal active operation of the system - specifically monitoring VSWR and/or doing TDR tests on the system.
It just seems that a -7 to -8 foot reading could have been more gracefully handled in system design.
Crew comments aside, I hope the final report provides more focus on the fault detection algorithym used on the LRRA systems and Boeing's requirements for self-fault detection.
Either there was an internal fault with the radio electronics themselves, or a fault developed in the transmission path (antenna & cabling). My understanding is that the RA is calibrated to read zero when on the ground on the gear. If the fault was internal to the electronics, this should have been trivial to code for and detect. Should the fault have delveloped in the 'dumb' portion of the system (cable and antenna) there are easy ways to test and detect that would not interfere with the normal active operation of the system - specifically monitoring VSWR and/or doing TDR tests on the system.
It just seems that a -7 to -8 foot reading could have been more gracefully handled in system design.
Per Ardua ad Astraeus
Joined: Mar 2000
Posts: 18,575
Likes: 4
From: UK
Southern - as RB says, if it relates to this thread and you have looked for the answer already, fire away. Generally we crusties only get angry when ridiculous posts are made here when previous info has not been looked at and c**p is repeated endlessy . If it is a non-thread related query, and you are not a commercial pilot, go to Spectators or Questions or Tech if you are, and we will try to answer it in a civil manner. Promise.
Wellington - they were NOT in cloud according to the briefing - cloudbase 700'. Metar given as "4500 Br Bkn007 Ovc008 " I reckon I'd see the ground from there - and, up or down would be instantly recognisable and they were supposedly trained to know. ..............almost RAF low flying weather......
Wellington - they were NOT in cloud according to the briefing - cloudbase 700'. Metar given as "4500 Br Bkn007 Ovc008 " I reckon I'd see the ground from there - and, up or down would be instantly recognisable and they were supposedly trained to know. ..............almost RAF low flying weather......