Habsheim
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Well, that's the same PDF that I've got, downloaded from the same location.
And you're right, it clearly says "Annexe VII", on the first page of the DFDR listing. But then, on page 45, halfway through the DFDR data, there is "Annexe VIII".
That is weird. That cannot be what they had intended, and it certainly does not match the table of appendices. But at least it would explain why the real appendix 7 (supposedly describing the CVR/DFDR synchronization) failed to get published.
Regarding the English version, all I know is that Asseline, in a rant about what he only calls "the Béchet report", complains that this piece of crap was even translated into English and then distributed among potential Airbus customers worldwide. Or something like that. Oh well.
And you're right, it clearly says "Annexe VII", on the first page of the DFDR listing. But then, on page 45, halfway through the DFDR data, there is "Annexe VIII".
That is weird. That cannot be what they had intended, and it certainly does not match the table of appendices. But at least it would explain why the real appendix 7 (supposedly describing the CVR/DFDR synchronization) failed to get published.
Regarding the English version, all I know is that Asseline, in a rant about what he only calls "the Béchet report", complains that this piece of crap was even translated into English and then distributed among potential Airbus customers worldwide. Or something like that. Oh well.
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Annexes/Appendices are usually used for supporting data, not narrative. An overview of how the flight data recorder was retrieved is in the BEA report, and an even more detailed description is in the Airbus "Executive Summary" report, along with the inadvertent error made by Capt. Davis in reading the output. Notably, the ACI programme got this wrong too - it was not ATC's discrepancy with the CVR, it was a misinterpretation of the DFDR. Capt. Davis seems to have treated the DFDR's transmit/receive flag as referring to the call from ATC (which would be almost 5 seconds adrift from the ATC recording and unacceptable). In fact the DFDR does not flag incoming, only outgoing transmissions, and the DFDR referred to the crew's response (just shy of 1 second adrift from the ATC timestamp, and within the margin of error).
All this and more is in the Airbus document - I don't understand why CONF is asking me to repeat tons of it.
Capt. Davis appeared in the Black Box series which was broadcast in 1996 and was listed as a former AAIB investigator. The UK TV programme about Asseline in which Capt. Davis attempted to decipher the recordings was broadcast in about 1989/1990 if I recall correctly. The last document I can find referring to his being active with AAIB was his work on the Air India bombing in 1985.
Regarding the English version, all I know is that Asseline, in a rant about what he only calls "the Béchet report", complains that this piece of crap was even translated into English and then distributed among potential Airbus customers worldwide. Or something like that. Oh well.
Incidentally, according to Béchet himself in the ACI/Mayday programme, Capt. Asseline was initially very co-operative. It was only when it appeared the investigation was disproving his claims that the aircraft malfunctioned that he turned so savagely on them.
Last edited by DozyWannabe; 30th Jan 2014 at 16:30.
Thread Starter
Noske and Dozy,
Whoever did that PDF made a real pig's-ear of l'assemblage, as the page numbers of the Annexes are clearly not even close to being sequential. However, some of the missing ones in "Additif" could be because the drawings/photos might have been one-sided, and the copier didn't even notice (s)he'd copied the blank sides.
Then there's the original itself...
The contents of several of the Annexes do not correspond to the index. The chaos includes the fact that (as you say, Noske) Annexe VII is listed in the index as "Correlation...", presumably a narrative justification of the method used to synchronise the timings of CVR, DFDR, Basel ATC, and Habsheim ATC. It is missing from that PDF.
Instead, the first 3 "Tomes" of the DFDR print-out are erroneously headed Appendix VII, and Tomes 4 - 6 (correctly) as Appendix VIII.
Quote from DozyW:
"The formatting of the data is different between Annexes 7 and 8. I suspect Annexe 7 is the *output used to synchronise* the complete DFDR data params (in Annexe 8) with the CVR."
I think not. In fact the most valuable point of correlation between DFDR and CVR probably occurs at TGEN 266 in Tome 5, which (as HN39 pointed out some time ago) is defined in the Airbus 1991 report as being 1244:31 GMT. That point (and hopefully at least one other) would have been used to insert a time stamp on the CVR transcript, as the CVR does not record any time stamp of its own, but (fortunately) runs at a steady speed. The correlation is the DFDR's discrete of the co-pilot's brief transmission on VHF1 (see also the CVR). So Tome 5 is essential in the correlation process.
BTW, I wasn't aware that Ray Davis, formerly of the AIB/AAIB, was a pilot, as you seem to be implying. At Farnborough in the 1980s, he was known simply as Ray Davis.
Whoever did that PDF made a real pig's-ear of l'assemblage, as the page numbers of the Annexes are clearly not even close to being sequential. However, some of the missing ones in "Additif" could be because the drawings/photos might have been one-sided, and the copier didn't even notice (s)he'd copied the blank sides.
Then there's the original itself...
The contents of several of the Annexes do not correspond to the index. The chaos includes the fact that (as you say, Noske) Annexe VII is listed in the index as "Correlation...", presumably a narrative justification of the method used to synchronise the timings of CVR, DFDR, Basel ATC, and Habsheim ATC. It is missing from that PDF.
Instead, the first 3 "Tomes" of the DFDR print-out are erroneously headed Appendix VII, and Tomes 4 - 6 (correctly) as Appendix VIII.
Quote from DozyW:
"The formatting of the data is different between Annexes 7 and 8. I suspect Annexe 7 is the *output used to synchronise* the complete DFDR data params (in Annexe 8) with the CVR."
I think not. In fact the most valuable point of correlation between DFDR and CVR probably occurs at TGEN 266 in Tome 5, which (as HN39 pointed out some time ago) is defined in the Airbus 1991 report as being 1244:31 GMT. That point (and hopefully at least one other) would have been used to insert a time stamp on the CVR transcript, as the CVR does not record any time stamp of its own, but (fortunately) runs at a steady speed. The correlation is the DFDR's discrete of the co-pilot's brief transmission on VHF1 (see also the CVR). So Tome 5 is essential in the correlation process.
BTW, I wasn't aware that Ray Davis, formerly of the AIB/AAIB, was a pilot, as you seem to be implying. At Farnborough in the 1980s, he was known simply as Ray Davis.
Last edited by Chris Scott; 1st Feb 2014 at 09:55. Reason: (In)discrete spelling.. Syntax error corrected in para 3.
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Regarding the PDF, it looks like the "additif" section consisted of double-sided pages, and either a blank page was left in situ on the side with the even numbered pages, or the scanner was incorrectly set up. This only seems to apply to that section however.
EDIT : Ouch - it looks like another scan hopper mistake was made in the original report Annexes - the pages between 26 and 32 seem to have been loaded initially in reverse, then almost random order. It does return to sequential order after that and no pages appear to be missing.
As I do regarding Mr. Davis above, we all need to be careful when "presuming" things about which we lack firm supporting evidence - I guess the only way to confirm the status of Annexe VII (which I'm still not convinced is erroneous) would be to write to the BEA themselves and ask.
Last edited by DozyWannabe; 30th Jan 2014 at 18:55.
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Originally Posted by Chris Scott
Instead, the first 3 "Tomes" of the DFDR print-out are erroneously headed Appendix VII, and Tomes 4 - 6 (correctly) as Appendix VIII.
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I will repost the link provided by noske:
About the correlation, the plain text of the report explains how the CVR was exploited (§1.11.1.1):
But no explanation of how CVR and DFDR were correlated; there is OTOH a mention saying it was good (§ 1.11.2):
Btw., for anyone frustrated with the poor quality PDF of the BEA report, here's a HTML version of it: Habsheim F-GFKC
Pour obtenir une chronologie précise, la vitesse de défilement de la bande a d'abord été recalée ŕ l'aide de la fréquence 400 Hz de l'alimentation électrique de bord qui apparaît dans le spectre enregistré. Ensuite, les enregistrements des émissions radio ont été corrélés avec ceux des fréquences du contrôle de la circulation aérienne (ces derniers comportent une piste horaire).
Enfin, la cohérence des données issues de l'exploitation du CVR, du DFDR et de certains moyens externes (photographies, bandes vidéo...) peut ętre qualifiée d'excellente.
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roulishollandais - This is getting a bit tiresome. The truth is that in all likelihood it is Capt. Asseline who is mistaken about there being a conspiracy/cover-up. He'd have probably realised this himself had certain parties not convinced him to pursue the angle for their own interests.
AZR - As HN39/Chris Scott pointed out earlier, in the Airbus supplementary report, page 17/33 the example given uses two VHF 1 transmissions to synchronise the timings:
CVR time 12H 44' 17" equated to DFDR time TGEN 252
CVR time 12H 44' 31" equated to DFDR time TGEN 266
CVR time 12H 44' 31" equated to DFDR time TGEN 266
Last edited by DozyWannabe; 30th Jan 2014 at 22:07.
Thread Starter
The co-pilot's VHF 1 transmission at 1244:31 (TGEN 266) is particularly good, IMO, because it is so brief and easily defined: "Recu."
They probably needed another as close to TGEN 000 as possible, in which case there should be a good opportunity at the beginning of the T/O. The CVR transcript shows "Ca roule 296 Q" (probably spoken as "Ca roule deux-cent quatre-vingt-seize quebec"?) with a retro time-stamp of 1240:44, which presumably coincides with a DFDR discrete starting at about TGEN 039.
Brief, knee-jerk acknowledgements are unlikely to be preceded by a pause with the Tx key already open. Transmissions requiring thought might be.
However, what the CVR transcript does not reveal is that (IIRC) the CVR has separate channels for each pilot's Tx, and each pilot's Rx, as well as the area microphone. Therefore, I would expect the co-pilot's Tx channel to pick up the sound of the transmit key being opened and closed. If so, the CVR keying event would be well within the one-second accuracy provided by the DFDR discretes.
Quote from HN39:
"In the html version of the Journal Officiel de la Republique Tomes 1 through 6 are in Appendix VIII, but Appendix no.7 is still missing."
Yes, the HTML version is so much better. Apart from the missing Annexe VIII, the only gripes are the lack of page numbering, and the Habsheim airfield plate being just as blurred as the PDF. The shambolic "Additif" section is not needed. I'm wondering if the PDF might have been created from an early draft of the Report.
They probably needed another as close to TGEN 000 as possible, in which case there should be a good opportunity at the beginning of the T/O. The CVR transcript shows "Ca roule 296 Q" (probably spoken as "Ca roule deux-cent quatre-vingt-seize quebec"?) with a retro time-stamp of 1240:44, which presumably coincides with a DFDR discrete starting at about TGEN 039.
Brief, knee-jerk acknowledgements are unlikely to be preceded by a pause with the Tx key already open. Transmissions requiring thought might be.
However, what the CVR transcript does not reveal is that (IIRC) the CVR has separate channels for each pilot's Tx, and each pilot's Rx, as well as the area microphone. Therefore, I would expect the co-pilot's Tx channel to pick up the sound of the transmit key being opened and closed. If so, the CVR keying event would be well within the one-second accuracy provided by the DFDR discretes.
Quote from HN39:
"In the html version of the Journal Officiel de la Republique Tomes 1 through 6 are in Appendix VIII, but Appendix no.7 is still missing."
Yes, the HTML version is so much better. Apart from the missing Annexe VIII, the only gripes are the lack of page numbering, and the Habsheim airfield plate being just as blurred as the PDF. The shambolic "Additif" section is not needed. I'm wondering if the PDF might have been created from an early draft of the Report.
Thread Starter
Quote from Dozy Wannabe:
"Agreed, but given their fast-and-high state, wouldn't those turns [to adjust track for Rwy 02] have provided at least some opportunity to slow down and thus manage the descent more precisely, whereas a straight-in to the 34 grass strip make slowing down and managing altitude precisely more difficult?"
As I wrote, there was little scope to increase the track distance from 3.5 nm. A sharp S-turn starting at 200 kts would have been impossible. So, for reasons I have already explained, the switch of runway made no significant difference. Ultimately, the essence of a descent for a direct approach is energy management, particularly on a jet, and energy was too high throughout.
The A320 was/is a conventional, medium-sized jet, perhaps marginally more slippery than a B737. The FBW computerisation makes no difference whatsoever to the mechanics of manoeuvrability or descent management. Ideally (and with a degree of hindsight), the PF should not have accelerated to 200 kt in transit. Having sensibly retained the T/O flap setting of 1+F, he could have maintained 'S' speed (about 182 kt at that weight). In need of drag, the L/G could have been extended about 10 seconds earlier, as soon as the field was in sight, and Flaps 2 simultaneously. But their workload was high, and continuing straight in (rather than joining the airfield circuit) was one of the decisions that they may have been pondering in the years since.
"Agreed, but given their fast-and-high state, wouldn't those turns [to adjust track for Rwy 02] have provided at least some opportunity to slow down and thus manage the descent more precisely, whereas a straight-in to the 34 grass strip make slowing down and managing altitude precisely more difficult?"
As I wrote, there was little scope to increase the track distance from 3.5 nm. A sharp S-turn starting at 200 kts would have been impossible. So, for reasons I have already explained, the switch of runway made no significant difference. Ultimately, the essence of a descent for a direct approach is energy management, particularly on a jet, and energy was too high throughout.
The A320 was/is a conventional, medium-sized jet, perhaps marginally more slippery than a B737. The FBW computerisation makes no difference whatsoever to the mechanics of manoeuvrability or descent management. Ideally (and with a degree of hindsight), the PF should not have accelerated to 200 kt in transit. Having sensibly retained the T/O flap setting of 1+F, he could have maintained 'S' speed (about 182 kt at that weight). In need of drag, the L/G could have been extended about 10 seconds earlier, as soon as the field was in sight, and Flaps 2 simultaneously. But their workload was high, and continuing straight in (rather than joining the airfield circuit) was one of the decisions that they may have been pondering in the years since.
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Dozy (re: #433) Thanks 
Grouches may point (and be right) that it's still missing in the "official" report (at least in the PDF version). I suggest the idea to go to a library to check a (really) official paper copy would do, for those interested.
(and remember: don't feed...)
Yes, that sounds right for a native
Grouches may point (and be right) that it's still missing in the "official" report (at least in the PDF version). I suggest the idea to go to a library to check a (really) official paper copy would do, for those interested.(and remember: don't feed...)
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Originally Posted by Chris Scott
The contents of several of the Annexes do not all correspond to the index. The chaos includes the fact that (as you say, Noske) Annexe VII is listed in the index as "Correlation...", presumably a narrative justification of the method used to synchronise the timings of CVR, DFDR, Basel ATC, and Habsheim ATC. It is missing from that PDF.
- Annexe 5 - Every single transmission between Basel ATC and ACF296Q has a timestamp but no FDR listing is provided for the period.
- Annexe 5 - Only a few transmission between Habsheim ATC and ACF296Q have a timestamp for the precise period a FDR listing is published.
No wonder Annexe 7 there is none.
But take a part of Annexe 8 to label it 7 ... why not.
Thread Starter
Linktrained,
"Habsheim was 25 years ago but still some of the lessons are there to be learned by newbies (as well as by one 86 year old !)"
Yes, it's said that when you stop learning, it's time to stop. Some of us are still learning, even though we already did...
"Today might be different !"
A little, but the basics are the same - only people's perceptions and expectations have changed. The air remains as fickle and fascinating as ever.
Check your PMs?
"Habsheim was 25 years ago but still some of the lessons are there to be learned by newbies (as well as by one 86 year old !)"
Yes, it's said that when you stop learning, it's time to stop. Some of us are still learning, even though we already did...
"Today might be different !"
A little, but the basics are the same - only people's perceptions and expectations have changed. The air remains as fickle and fascinating as ever.
Check your PMs?
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rudderrudderrat
Quote
It appears to me that the aircraft was deliberately flown below 50 RA with the speed allowed to wash off, apparently waiting for Alpha Floor to "save the day". Unquote
I think that was precisely it. Everyone seems to have missed it - no mention from Chris Scott about it either.
He forgot below 100 feet.
He most likely applied full back press on the stick, waiting, as you said for Alpha Floor to kick in - it did not, aircraft THOUGHT IT WAS LANDING - too.
No alpha floor, no toga to boot. = No noisy climb out.
Had he have done all the above at >100` RA then we would not be having this thread.
Quote
It appears to me that the aircraft was deliberately flown below 50 RA with the speed allowed to wash off, apparently waiting for Alpha Floor to "save the day". Unquote
I think that was precisely it. Everyone seems to have missed it - no mention from Chris Scott about it either.
He forgot below 100 feet.
He most likely applied full back press on the stick, waiting, as you said for Alpha Floor to kick in - it did not, aircraft THOUGHT IT WAS LANDING - too.
No alpha floor, no toga to boot. = No noisy climb out.
Had he have done all the above at >100` RA then we would not be having this thread.
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Originally Posted by rudderruddererat
the aircraft was deliberately flown below 50 RA with the speed allowed to wash off,
That has been pointed by the expert Max Venet at the trial,. He asked too to cut these trees computing with a patented Venet software the path (one addition or one substraction for each tree ($$$$...).
But these trees were unknown from the pilots who previewed to fly over the other runway. I studied the VAL chart and discovered that the grass ruway was already illegal for light single engine airclub planes... Today that runway no more exists...
Question is : did Asseline DELIBERATELY ovefly these seldom trees? Really I don't think it.
Thread Starter
le Bosquet
Bon soir roulis,
The copse ("bosquet") that they overflew, causing the two-second ramp of radio altimeter readings, was just outside the airfield boundary, and roughly south-east of the Rwy 02 threshold. At that time, they were in a gentle right turn (about 10 deg of bank) to line up with the grass Rwy 34R.
The current satellite map shows a fairly large wooded area south-east of the airfield, and (assuming it already existed in 1988) they probably overflew the west corner of it. As they had not been briefed of the existence of the wood at the north boundary, it seems unlikely that they would have known of the wood to the south-east.
The two readings indicating the "copse" were 32 ft at TGEN 313 (t -21 seconds) and 24 ft at TGEN 314 (t -20 sec). The reading recorded at the next second was 60 ft, and the a/c did not level off until about t -13 sec, by which time I estimate it had passed abeam the Rwy 34L grass threshold, and was just short of the Rwy 34R grass threshold.
At level-off (TGEN 321, or t -13 sec), the rad alt showed a height of 40 ft. At the same time, the pressure altitude was +869 ft, from which I calculate the pilots' altimeters (set to the QFE of 984 hPa) would have been indicating about 60 ft.
The copse ("bosquet") that they overflew, causing the two-second ramp of radio altimeter readings, was just outside the airfield boundary, and roughly south-east of the Rwy 02 threshold. At that time, they were in a gentle right turn (about 10 deg of bank) to line up with the grass Rwy 34R.
The current satellite map shows a fairly large wooded area south-east of the airfield, and (assuming it already existed in 1988) they probably overflew the west corner of it. As they had not been briefed of the existence of the wood at the north boundary, it seems unlikely that they would have known of the wood to the south-east.
The two readings indicating the "copse" were 32 ft at TGEN 313 (t -21 seconds) and 24 ft at TGEN 314 (t -20 sec). The reading recorded at the next second was 60 ft, and the a/c did not level off until about t -13 sec, by which time I estimate it had passed abeam the Rwy 34L grass threshold, and was just short of the Rwy 34R grass threshold.
At level-off (TGEN 321, or t -13 sec), the rad alt showed a height of 40 ft. At the same time, the pressure altitude was +869 ft, from which I calculate the pilots' altimeters (set to the QFE of 984 hPa) would have been indicating about 60 ft.
Last edited by Chris Scott; 10th Feb 2014 at 23:28. Reason: Last para added.
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Quote
It appears to me that the aircraft was deliberately flown below 50 RA with the speed allowed to wash off, apparently waiting for Alpha Floor to "save the day". Unquote
I think that was precisely it. Everyone seems to have missed it - no mention from Chris Scott about it either.
It appears to me that the aircraft was deliberately flown below 50 RA with the speed allowed to wash off, apparently waiting for Alpha Floor to "save the day". Unquote
I think that was precisely it. Everyone seems to have missed it - no mention from Chris Scott about it either.
Regarding the online version of the report, I made the following observations:
- Looking at the PDF properties, the online PDF version was created on the 10th June 2008 and last modified (presumably uploaded) on the 12th
- The PDF Producer field lists "Acrobat Distiller 8" for Windows. Acrobat Distiller is usually used for converting existing digital documents in the PostScript format to PDF
- This therefore implies that the document was scanned some time before it was converted for the web. It's entirely possible that the original PostScript file was scanned years prior to conversion and uploading
- A random sampling of documents from the site of a similar vintage shows that the conversion and upload was performed in bulk batches
- The same random sampling indicates that the documents of similar vintage are of similar fidelity to the Habsheim report, including a similar number of scanning errors
- It should also be noted that (for example) online NTSB reports of a similar vintage are of similar fidelity, being image-centric PDFs and equally troublesome to extract textual data from electronically
The BEA's search form indicates that there are currently 2,256 individual documents in their web-accessible archive. It seems reasonable to infer that to proof-read and correct each of these documents individually would be a mammoth task in terms of man-hours and expense. That the accessible reports from the NTSB and UK AAIB of a similar vintage are also of a similar quality indicates that these archives are supplied "as-is", and some scanning/conversion errors are to be expected.
Furthermore, the appendices/"annexes" of such reports are intended for use only as reference data for the reports themselves. They are not intended for use as the basis of amateur investigations, nor should their content be criticised by amateur investigators for being unable to suit their specific needs.
It must be borne in mind that when this version of the report was published in April 1990, the web existed only as a paper proposal at CERN. The report itself is obviously aimed purely at the print medium, and the CVR transcript could be condensed via word processing in a way that the DFDR output could not. That the DFDR output included in the appendices deals with the immediate precursors of the accident sequence only, and earlier analysis is provided in the narrative makes sense if one takes this into account.
There is absolutely no evidence to suggest that this particular report, either in general or with specific regard to the archival version available online, was intentionally rendered difficult to interpret - it is simply an artifact of its time.
@roulishollandais - in addition to Chris Scott's answer above, it's worth reiterating that overflying the copse of trees made no difference to the behaviour of the aircraft.
Thread Starter
Alpha-Floor inhibition
Quote from rudderrudderrat:
"It appears to me that the aircraft was deliberately flown below 50 RA with the speed allowed to wash off, apparently waiting for Alpha Floor to 'save the day'. "
Response from Natstrackalpha:
"I think that was precisely it. Everyone seems to have missed it - no mention from Chris Scott about it either."
Welcome, Natstrackalpha. For Airbus FBW pilots and long-term readers of Habsheim discussions, Alpha-Floor inhibition below 100R (100 ft on the radio-altimeter) is a given. The trigger for this thread occurred on AF447 Thread 11, in which we were briefly discussing the inhibition criteria. I rashly cited Habsheim, and CONF_iture had to remind me that the captain had clearly briefed that he would inhibit (disable) Alpha Floor manually to cater for his plan to achieve a stabilised Alpha-max at 100ft on the QFE - at which the height on the rad-alt might be higher or lower than 100R. My reply was copied to form the first post of this Habsheim thread, which was instigated by CONF_iture (see his post #2). Re Alpha-Floor inhibition, I refer you to my first and last paragraphs.
Regarding the flypast as executed, you will have noted that it was flown well below 100R, and (as Dozy Wannabe writes above) it is not entirely clear whether the captain ever carried out his briefed manual inhibition of Alpha Floor.
It is not unreasonable to speculate that, notwithstanding the briefing recorded on the CVR, Capt Asseline may have planned to fly below 100ft all along. This was certainly not incompetence, because his height-keeping after level-off at t -13 (see my post to roulishollandais above) was remarkably accurate – whether you study the baro readings, or the heights recorded from the rad-alt. Although he did lose height, it amounted to no more than 10 ft on his baro-altimeter, and the same on the rad-alt. He has stated that he was using only his baro altimeter throughout, and claims that it must have been giving false readings, but – other than his own testimony – I’m not aware of any evidence to support that.
You argue that, if they had flown the flypast above 100R, Alpha Floor would have prevented the accident. But at that height, they would have cleared the treetops anyway - provided TOGA had been selected manually in time to stop the inevitable sink with flight-idle at Alpha-max.
BTW, how's the conversion going?
"It appears to me that the aircraft was deliberately flown below 50 RA with the speed allowed to wash off, apparently waiting for Alpha Floor to 'save the day'. "
Response from Natstrackalpha:
"I think that was precisely it. Everyone seems to have missed it - no mention from Chris Scott about it either."
Welcome, Natstrackalpha. For Airbus FBW pilots and long-term readers of Habsheim discussions, Alpha-Floor inhibition below 100R (100 ft on the radio-altimeter) is a given. The trigger for this thread occurred on AF447 Thread 11, in which we were briefly discussing the inhibition criteria. I rashly cited Habsheim, and CONF_iture had to remind me that the captain had clearly briefed that he would inhibit (disable) Alpha Floor manually to cater for his plan to achieve a stabilised Alpha-max at 100ft on the QFE - at which the height on the rad-alt might be higher or lower than 100R. My reply was copied to form the first post of this Habsheim thread, which was instigated by CONF_iture (see his post #2). Re Alpha-Floor inhibition, I refer you to my first and last paragraphs.
Regarding the flypast as executed, you will have noted that it was flown well below 100R, and (as Dozy Wannabe writes above) it is not entirely clear whether the captain ever carried out his briefed manual inhibition of Alpha Floor.
It is not unreasonable to speculate that, notwithstanding the briefing recorded on the CVR, Capt Asseline may have planned to fly below 100ft all along. This was certainly not incompetence, because his height-keeping after level-off at t -13 (see my post to roulishollandais above) was remarkably accurate – whether you study the baro readings, or the heights recorded from the rad-alt. Although he did lose height, it amounted to no more than 10 ft on his baro-altimeter, and the same on the rad-alt. He has stated that he was using only his baro altimeter throughout, and claims that it must have been giving false readings, but – other than his own testimony – I’m not aware of any evidence to support that.
You argue that, if they had flown the flypast above 100R, Alpha Floor would have prevented the accident. But at that height, they would have cleared the treetops anyway - provided TOGA had been selected manually in time to stop the inevitable sink with flight-idle at Alpha-max.
BTW, how's the conversion going?
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Regarding competency, I think it would have been impossible for a pilot to be selected for that role without being a very competent hand-flyer, and you're right about his holding the altitude fairly stable. However on this occasion it was his decision-making that fell short - a consequence of which was substandard thrust and speed management.
As you've said before, there was ample opportunity to circle, descend and then achieve a more stable short final - I believe that the old "press-on-itis" psychology had a hand in their not doing so.
Last edited by DozyWannabe; 11th Feb 2014 at 13:06.
From the "light" peanut gallery @ Doze and Chris....
Yep, Doze, "pride" gets in the way one or two times, but usually only once. Our aviation mistress is harsh in that regard.
The "press on" attitude may apply in combat, but otherwise it is not a smart thing regardless of how good your "hands" are. I know about the combat reference from one mission, but I digress.
Let's face it, the dude had a poor setup and tried to "save" it. In any other plane at that time, he would likely have stalled and crashed right in front of everybody there. The "magic" protections and limiters can only do so much, and flying at the "limits" when carrying SLF and such is not very "professional" to this old pilot.
Yep, Doze, "pride" gets in the way one or two times, but usually only once. Our aviation mistress is harsh in that regard.
The "press on" attitude may apply in combat, but otherwise it is not a smart thing regardless of how good your "hands" are. I know about the combat reference from one mission, but I digress.
Let's face it, the dude had a poor setup and tried to "save" it. In any other plane at that time, he would likely have stalled and crashed right in front of everybody there. The "magic" protections and limiters can only do so much, and flying at the "limits" when carrying SLF and such is not very "professional" to this old pilot.