Air Canada A320 accident at Halifax
I understand this is your best attempt at making this graph which looks good to me.
So in conclusion using your graph...
- The crew did not program the right flight path into the aircraft's FMCs because they were below the temperature corrected flight path.
- You can't rely on the radar altitude call out at 400' or 100' because of the terrain. In fact when the auto calls at 400' and 100' were given they were actually a lot closer to the ground then one would expect.
- The PM's call of "minimums, lights only" came at or slightly below the uncorrected cold temperature MDA, perhaps 50 to 60 feet below what the corrected MDA was on that night.
- The captain's call of "landing" came at an even lower uncorrected MDA.
- At approximately 150' above ground, both pilots have a "conversation" about the approach lights.
- Autopilot disconnect happens at less than 50' above ground. It would be interesting to know the A320's autopilot minimum descent limits are on a non precision approach.
- The captain's G/A initiation starts below the RWY's threshold altitude with the known consequences.
I am not an expert in crash analysis but it sure looks to me that the crew busted minimums without having the proper visual clues to continue below the MDA. This might have been further compounded by several technical errors from them in the way they programmed the FMCs (I'm not qualified on the A320) and did not apply the temperature corrected altitudes at least at the MDA.
So in conclusion using your graph...
- The crew did not program the right flight path into the aircraft's FMCs because they were below the temperature corrected flight path.
- You can't rely on the radar altitude call out at 400' or 100' because of the terrain. In fact when the auto calls at 400' and 100' were given they were actually a lot closer to the ground then one would expect.
- The PM's call of "minimums, lights only" came at or slightly below the uncorrected cold temperature MDA, perhaps 50 to 60 feet below what the corrected MDA was on that night.
- The captain's call of "landing" came at an even lower uncorrected MDA.
- At approximately 150' above ground, both pilots have a "conversation" about the approach lights.
- Autopilot disconnect happens at less than 50' above ground. It would be interesting to know the A320's autopilot minimum descent limits are on a non precision approach.
- The captain's G/A initiation starts below the RWY's threshold altitude with the known consequences.
I am not an expert in crash analysis but it sure looks to me that the crew busted minimums without having the proper visual clues to continue below the MDA. This might have been further compounded by several technical errors from them in the way they programmed the FMCs (I'm not qualified on the A320) and did not apply the temperature corrected altitudes at least at the MDA.
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From the TSB report: "As the aircraft descended, the actual flight path diverged from the desired profile as a result of wind variations. The divergence continued to increase throughout the approach. The airspeed was constant, and the vertical descent speed ranged between 700 and 800 feet per minute (fpm)."
The report analyses the calculations of the crew and finds them correct; the crew computed and presumably set a FPA of 3.5° (for an actual angle of 3.08°), but the FDR shows their actual path vs. indicated altitude was 3.77°. On a normal visual approach, the pilot will compensate as she flies the approach from MDA when the autopilot is turned off, so it's not usually an issue. TSB report Section 1.18.2 discusses the Airbus FPA guidance mode and the possible deviation.
The interesting part is that the airplane flew an actual 3.50° descent. Since the ADIRS also uses inertial inputs to determine height, and these are not affected by temperature, it is possible that the unit did actually do as programmed and steered the plane down an actual 3.5° slope, effectively ignoring the barometric deviation; this would be contrary to published documentation. (Undocumented behaviour is not uncommon in the software realm.)
The report also mentions in 1.18.3 that Airbus intially got the procedures wrong, as was discovered in 2009, and it was supposedly corrected by Air Canada and Airbus under Transport Canada's supervision.
I'm sure somebody at Airbus knows if my theory (ADIRS working inertial and non-barometric) or the TSB's "wind perturbation" theory is correct.
JJA4, I will try to confirm your conclusions or otherwise, but a major problem is that we can only go by the TSB report which raises MANY unanswered questions that I cover in the critique referenced previously.
The flight path was programmed according to AC's procedures, as far as I can tell. However there are questions about what the temp-corrected angle should have been; the descent initiation point; a rounding error (exact angle could not be set); and how "wind variations" could have affected the FPA actually flown. Also in my opinion although it seems nuts not to have any crosschecks on the way down, the way Air Canada implemented temperature corrections made this difficult. Overall one can only say that the crew seem to have actually conducted the instrument descent in accordance with the SOPs they had been given. (Report para 1.18.3). There is no question the the flight path achieved did not bring the aircraft to the correct point, and this was not detected by the crew. But who was responsible for that is not clear.
Correct. The terrain profile on my chart was a screen grab from the TSB presentation crosschecked against Google Earth.
Correct as possible without FDR/CVR
Likewise.
Disconnect was about 30ft above threshold elevation, 16 ft above touchdown zone elevation. The minimum autopilot height was MDA -50 but the report does not say whether the MDA had been entered in the FMC or whether the crew observed the "disconnect A/P" warning - one of the many failings in the report.
Close to or below. Certainly below the TDZ elevation.
But the report is quite specific that "the crew" had the legally required visual reference at the MDA. The crew actually followed the law and their procedures and still crashed! But nobody was killed. I wonder if that is why the report has been able to get away with not even mentioning any of the implications of that astonishing fact. This time, it wasn't all the crew's responsibility - so whose was it?
I am not an expert in crash analysis but it sure looks to me that the crew busted minimums without having the proper visual clues to continue below the MDA. This might have been further compounded by several technical errors from them in the way they programmed the FMCs (I'm not qualified on the A320) and did not apply the temperature corrected altitudes at least at the MDA.
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But the report is quite specific that "the crew" had the legally required visual reference at the MDA.
Sure? How is that visual reference defined? If it is simply 'approach lights' that IMHO is insufficient; unless it assumes that there pilots are responsible for determining that 'approach lights' are not car park or highway lights. If so, that requires the pilots to know exactly what type of approach lights they expect to see at MDA and how much of then defines 'approach lights'. Because here is not correlation between MDA and approach light length and viability, it is difficult to assess what you might see at MDA. So to define what is legal and what is not is beyond grey area; it is deep in the most & fog of uncertainty. That is not what you need so close to invisible ground. 'Hoping' that the lights you see will guide you to a safe landing on the runway should not be the name of our game. We and the pax need more certainty.
Sure? How is that visual reference defined? If it is simply 'approach lights' that IMHO is insufficient; unless it assumes that there pilots are responsible for determining that 'approach lights' are not car park or highway lights. If so, that requires the pilots to know exactly what type of approach lights they expect to see at MDA and how much of then defines 'approach lights'. Because here is not correlation between MDA and approach light length and viability, it is difficult to assess what you might see at MDA. So to define what is legal and what is not is beyond grey area; it is deep in the most & fog of uncertainty. That is not what you need so close to invisible ground. 'Hoping' that the lights you see will guide you to a safe landing on the runway should not be the name of our game. We and the pax need more certainty.
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The TSB seems quite certain as to the legality. From section 2.5 of the report: "As the aircraft reached the calculated MDA, both crew members observed some approach lights. These cues meet the criteria for required visual reference per the Air Canada Flight Operations Manual, the Transport Canada Aeronautical Information Manual, and the Canada Air Pilot general pages."
Thanks for the info Musician but I am really confused by the FMCs in the Airbus.
Seems like a very complicated system just to have some sort of VPATH during an approach. It reminds me of the Air France A320 crash during an approach in France near Strasbourg IIRC... tell me it wasn't the same type of error here?
Maybe the TSB is convinced that both pilots saw the approach lights but I remain a skeptic especially if the graph provided slast is correct in its time lines.
Does anyone with Airbus 320 experience know what the minimum altitude for autopilot use (AFM limitation) is on this type of approach (non precision) for the A320?
Seems like a very complicated system just to have some sort of VPATH during an approach. It reminds me of the Air France A320 crash during an approach in France near Strasbourg IIRC... tell me it wasn't the same type of error here?
Maybe the TSB is convinced that both pilots saw the approach lights but I remain a skeptic especially if the graph provided slast is correct in its time lines.
Does anyone with Airbus 320 experience know what the minimum altitude for autopilot use (AFM limitation) is on this type of approach (non precision) for the A320?
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Does anyone with Airbus 320 experience know what the minimum altitude for autopilot use (AFM limitation) is on this type of approach (non precision) for the A320?
An earlier poster said MDA -50'. I think. I doubt this was similar to the Air Inter Strasbourg crash. That was a mix up between FPA & V/S. There was a huge difference between FPA 3degrees & 3000fpm. In this case they were only a few feet too low, but enough.
I read that AC was threatening to sue Airbus for designing a system that did not bring the aircraft to the threshold as advertised. After reading the report that seems a stretch as to where blame should lie.
An earlier poster said MDA -50'. I think. I doubt this was similar to the Air Inter Strasbourg crash. That was a mix up between FPA & V/S. There was a huge difference between FPA 3degrees & 3000fpm. In this case they were only a few feet too low, but enough.
I read that AC was threatening to sue Airbus for designing a system that did not bring the aircraft to the threshold as advertised. After reading the report that seems a stretch as to where blame should lie.
The A320 FCOM limits autopilot use to MDA minus 50’ on a non-precision approach. If I recall correctly, a NPA procedure that is flown fully managed (approach path computed and flown by the FMGC) will lead to the autopilot disconnecting automatically at MDA minus 50’, but this does not occur when the approach is flown with a pilot-selected flight path angle.
RAT 5, I entirely agree with your sentiments. However as I have been banging on about for some time, it seems Canada DOES allow descent below MDA solely on approach lighting (unspecified) having been visible at DH/MDA, because this will "enable" the flight path to be assessed. Whereas elsewhere (Annex 6 etc) the cues must have been in view for sufficient time for the pilot to HAVE MADE that assessment. That is also (I believe) in the Airbus FCTM - DH/MDA marks the end of any assessment. In Canada you can BEGIN it there. Of course if you then assess it as NOT satisfactory you are in trouble, being below the safe go-around height.
Re the autopilot, not only is the FM limit as already stated by J.O. (MDA-50ft), but "an amber message DISCONNECT AP FOR LDG is displayed when, during a Non Precision Approach, the AP/FD remains engaged at Minimum minus 50 ft, or ‐ 400 ft AGL (if no minimum entered)."
In this case, there is no record of whether the crew entered the MDA in the MCDU. If it was, then it would have been 813' indicated, 790' true, vs the actual MDA of 740'. This message should have come on at the actual MDA, which also ties in with the a 50ft addition to the published MDA when using a CDFA, as in this case. If it was NOT set, it would have come on at 400ft AGL simultaneously with the 400 auto callout, which because of the sloping terrain was actually only about 300ft above the TDZ.
This message should therefore have been visible but there is no record of whether either crew member observed it, and if so made the required callout.
Re the autopilot, not only is the FM limit as already stated by J.O. (MDA-50ft), but "an amber message DISCONNECT AP FOR LDG is displayed when, during a Non Precision Approach, the AP/FD remains engaged at Minimum minus 50 ft, or ‐ 400 ft AGL (if no minimum entered)."
In this case, there is no record of whether the crew entered the MDA in the MCDU. If it was, then it would have been 813' indicated, 790' true, vs the actual MDA of 740'. This message should have come on at the actual MDA, which also ties in with the a 50ft addition to the published MDA when using a CDFA, as in this case. If it was NOT set, it would have come on at 400ft AGL simultaneously with the 400 auto callout, which because of the sloping terrain was actually only about 300ft above the TDZ.
This message should therefore have been visible but there is no record of whether either crew member observed it, and if so made the required callout.
DISCONNECT AP FOR LDG
Only half a speed-brake
The older ones actually should be even more intuitive. At FMS inserted MDA -50 ft, the AP should trip off and FDs revert to basic HDG-V/S modes. Mode announciators boxed on FMA, FD bars flashing, and audio triple click.
In your graph (lot of meticulous work behind it!) do I read it correctly that the vertical axis reference is corrected ALT, thus the corrected profile line is different from the geometrical path green line?
Secondly, to leech on your research further: Does the report mention anything about the V-DEV indicator (yo-yo / doughnut) and indications displayed on the PFD?
Thanks.
In your graph (lot of meticulous work behind it!) do I read it correctly that the vertical axis reference is corrected ALT, thus the corrected profile line is different from the geometrical path green line?
Secondly, to leech on your research further: Does the report mention anything about the V-DEV indicator (yo-yo / doughnut) and indications displayed on the PFD?
Thanks.
Far left GREEN scale is just a measured tape covering the range needed, placed to match threshold elevation.
Next to it is a RED scale which is the green one geometrically stretched to cover the temperature correction, and moved so that field elevation matches correctly. Thanks to Locked Door post#382 for correcting my error on this.
Right hand GREY scale is same gradations as GREEN i.e. true feet but zeroed at touchdown zone elevation.
Green solid "nominal flight path" is from 2000ft msl at the FAF Split Crow to the ideal aiming point and PAPI location.
Yellow solid line is the 3.08 degree VDA from Split Crow, which is slightly below the ideal, but seems to cross the threshold "at about 50ft" - the threshoild being 14ft lower than the TDZ.
Red dashed line is the planned descent path, using the temperature adjusted crossing height at the FAF to the TDZ. The plan was to fly as close as possible to this by setting the FPA to -3.5deg in accordance with AC's table.
Red solid line represents as best I can fit it the aircraft flight path. Descent from FAF was started slightly early. So at for example 4 DME from I-HZ, the aircraft should have been ideally at 1250 ft true alt (green scale). But because of Air Canada cold temp adjustments were in 100ft increments (presumably up), this aircraft should have had an altimeter reading of 1350 ft. (red scale) at this point. However if my analysis is right, the altimeter reading (red scale) would actually have been 1250 ft, the charted value for 4 DME, although the aircraft was actually 60 ft low.
Inset chart shows a blown-up section of the report's FDR readouts.
leech away! My objective to stop accidents where pilots are personally blamed for making predictable errors that could easily been prevented, if the airline had made suitable procedural changes and/or provided better training, so any comments that might ensure this stuff is correct are welcome.
Not that I've seen. It misses lots of information as noted in the critique.
Last edited by slast; 2nd Nov 2017 at 17:40. Reason: Addition of 4DME altimeter readings
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FPA uses baro-inertial vertical speed and therefore FPA is affected by non-standard temperatures and consequntly requires temperature correction.
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FPA uses baro-inertial vertical speed and therefore FPA is affected by non-standard temperatures and consequntly requires temperature correction.
With various errors possible, FPA, baro-altimeter,......it is still surprising that AC SOP's did not include a vertical profile check via ALT v DME, especially as the table is on the chart. I also find it surprising that the self-survival instincts of a pilot would not do it anyway. I've asked the question about whether it is now an SOP; no reply yet.
I hope this was not a case of a pilot NOT doing something of basic airmanship nature because it was not an SOP. It doesn't say you are not allowed it do it, just that it is not mandatory to do it. That philosophy reminds of one company that removed the SBY ILS from the Approach checklist so the more lazy guys interpreted this as it was not necessary to select it on. That struck me with sadness as it indicated that the trained monkey syndrome was too prevalent. I'm not saying that was the case in AC, just asking.
With various errors possible, FPA, baro-altimeter,......it is still surprising that AC SOP's did not include a vertical profile check via ALT v DME, especially as the table is on the chart. I also find it surprising that the self-survival instincts of a pilot would not do it anyway. I've asked the question about whether it is now an SOP; no reply yet.
I hope this was not a case of a pilot NOT doing something of basic airmanship nature because it was not an SOP. It doesn't say you are not allowed it do it, just that it is not mandatory to do it. That philosophy reminds of one company that removed the SBY ILS from the Approach checklist so the more lazy guys interpreted this as it was not necessary to select it on. That struck me with sadness as it indicated that the trained monkey syndrome was too prevalent. I'm not saying that was the case in AC, just asking.
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Slast, I would like to commend you on such a detailed critique of the Canadian TSB report on AC624.
I must admit, I would not have ever thought, that the Canadian TSB would ever "sugar coat" their findings! I have always had the utmost respect for their findings, and now this revelation has me questioning their motive in not reporting in detail the actual events.
I must admit, I would not have ever thought, that the Canadian TSB would ever "sugar coat" their findings! I have always had the utmost respect for their findings, and now this revelation has me questioning their motive in not reporting in detail the actual events.
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I was also shocked on how much information the TSB report glossed over.
I did not read all the thread here, but I did spend some hours going over the report with a fine comb some weeks ago. From memory here is what I have found. Sorry if I repeat what others have already mentionned.
1) The report does not mention if the accident aircraft had or did not have GPS.
2) The report does not mention if the pilots made an accuracy check, as the required of A320s that have no GPS
3) The report does not mention if the pilots had "Accuracy High" in the Prog page.
4) The report does not mention if the pilot had tuned the DME frequency.
5) The report does not mention if the pilots had tuned the NDB frequency
6) The report does not mention how the pilots determined they had reached the final descent point (FAF)
7) The report mentions that second "Gate" by quoting the Air Canada procedures, but never mentions how the crew implemented or failed to implement that procedure.
8) The report avoids stating that the crew went below minimums but only suggests it by stating that the MDA was passed at 1.2 NM and that the PM called lights only at 1.0 NM.
At a ground speed of about 130 kts, 0.2 NM is roughly six second after, and about75 feet below the MDA. Not much, but much longer that I expect from my PM when I'm flying an approach to minimums.
9) The report fails to mention if the crew had entered the CYHZ05 in the PROG page as is normal procedure for these aircraft.
10) The report fails to mention what waypoint was in the database after the FAF. Was it a threshhold, a MAP or some other point ? That would give an idea of what the yoyo would have indicated, and if that might have influenced the crew.
11) The report fails to mention what data was used to create figure 1. Was it the FMS data ? If it was, was the IRS based FMS data valid ? If it was, how do we know it was ? This brings us back to point 2 and 3 above.
12) The report failed to indicate if the crew selected a LOC05 in the FMS, anf if they manually entered a corrected altitude at the FAF in the FMS, or if they just computed it for the FAF without changing the FMS provided FAF (uncorrected) crossing altitude.
13) The report states that the crew computed a corrected MDA of 813 feet. But the report fails to indicate if the crew entered that corrected MDA in the FMS or the regular MDA.
14) The actual communications between the two pilots are not provided, but are just paraphrased. The real verbatim exchange would have provided an insight of what actually went wrong......
There are many other things I have issues with, but what I described above is enough for me to have lost the blind faith I had in the TSB .....
It's a shame they did this, for they shot themselves in the foot. This report will be the proof that lawyers will produce in the future to question the credibility of the TSB when they will be tasked with a more important and complex investigation, one with say, hundreds of lost lives. Will Canada have to outsource their investigations because of this ?
I still think they are competent and would have been capable of writing a good report. Why they produced this half baked report, we'll leave to speculation.
I did not read all the thread here, but I did spend some hours going over the report with a fine comb some weeks ago. From memory here is what I have found. Sorry if I repeat what others have already mentionned.
1) The report does not mention if the accident aircraft had or did not have GPS.
2) The report does not mention if the pilots made an accuracy check, as the required of A320s that have no GPS
3) The report does not mention if the pilots had "Accuracy High" in the Prog page.
4) The report does not mention if the pilot had tuned the DME frequency.
5) The report does not mention if the pilots had tuned the NDB frequency
6) The report does not mention how the pilots determined they had reached the final descent point (FAF)
7) The report mentions that second "Gate" by quoting the Air Canada procedures, but never mentions how the crew implemented or failed to implement that procedure.
Air Canada's Stable Approach Policy is built around an Arrival Gate concept whereby a flight shall not continue the approach unless the required criteria for each Arrival Gate are met. There are two Arrival Gates for every approach; the first is the FAF (or FAF equivalent), the second Arrival Gate is at 500 feet AGL (or 100' above minimums, whichever is higher). A Go-around is mandatory if the criteria for each Arrival Gate is not met.
For non-precision approach, at the first Arrival Gate (FAF), the aircraft must be on the inbound course and on the descent profile defined by the FPA, the vertical speed, or the flight management guidance system.
No flight shall continue an approach past the FAF Arrival Gate unless it is being flown in a way that ensures the Stable Approach Criteria will be met by the 500 foot Arrival Gate.
At the second gate (500 feet AGL or 100 feet above the MDA), no flight shall continue unless the following stable approach criteria are met:
Established on the correct vertical approach path
For non-precision approach, at the first Arrival Gate (FAF), the aircraft must be on the inbound course and on the descent profile defined by the FPA, the vertical speed, or the flight management guidance system.
No flight shall continue an approach past the FAF Arrival Gate unless it is being flown in a way that ensures the Stable Approach Criteria will be met by the 500 foot Arrival Gate.
At the second gate (500 feet AGL or 100 feet above the MDA), no flight shall continue unless the following stable approach criteria are met:
Established on the correct vertical approach path
Almost immediately after this call, the aircraft crossed the calculated MDA at 1.2 nm from the threshold. The PM observed some approach lights and called, "Minimum, lights only," when the aircraft was about 1.0 nm from the threshold.
9) The report fails to mention if the crew had entered the CYHZ05 in the PROG page as is normal procedure for these aircraft.
10) The report fails to mention what waypoint was in the database after the FAF. Was it a threshhold, a MAP or some other point ? That would give an idea of what the yoyo would have indicated, and if that might have influenced the crew.
11) The report fails to mention what data was used to create figure 1. Was it the FMS data ? If it was, was the IRS based FMS data valid ? If it was, how do we know it was ? This brings us back to point 2 and 3 above.
12) The report failed to indicate if the crew selected a LOC05 in the FMS, anf if they manually entered a corrected altitude at the FAF in the FMS, or if they just computed it for the FAF without changing the FMS provided FAF (uncorrected) crossing altitude.
13) The report states that the crew computed a corrected MDA of 813 feet. But the report fails to indicate if the crew entered that corrected MDA in the FMS or the regular MDA.
14) The actual communications between the two pilots are not provided, but are just paraphrased. The real verbatim exchange would have provided an insight of what actually went wrong......
There are many other things I have issues with, but what I described above is enough for me to have lost the blind faith I had in the TSB .....
It's a shame they did this, for they shot themselves in the foot. This report will be the proof that lawyers will produce in the future to question the credibility of the TSB when they will be tasked with a more important and complex investigation, one with say, hundreds of lost lives. Will Canada have to outsource their investigations because of this ?
I still think they are competent and would have been capable of writing a good report. Why they produced this half baked report, we'll leave to speculation.
Last edited by Gilles Hudicourt; 23rd Nov 2017 at 16:01. Reason: had written a corrected MDA of 740 instead of 813
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I noted that several people asked why this runway does not have an ILS.
There are terrain features that prohibit the installations of an ILS, and one of those is if the terrain on the runway axis a certain distance before the threshold is nor fairly flat for a certain distance, in order for the Radio altimeter, which does not measure the height of the aircraft above the runway, but the height of the aircraft above the terrain directly below it, to be able to activate certain features such as flare mode, or changes flight laws, elevator trim, auto thrust etc. Even a dinosaur like the 737NG has such RA dependent features.
Such features would not work correctly if the terrain half a mile before the threshold was significantly higher or lower than the runway threshold.
I remember in a distant past flying ILS approaches in aircraft that did not even have a RA, but the aircraft I now fly prohibits ILS approaches if both RA are U/S.
There are terrain features that prohibit the installations of an ILS, and one of those is if the terrain on the runway axis a certain distance before the threshold is nor fairly flat for a certain distance, in order for the Radio altimeter, which does not measure the height of the aircraft above the runway, but the height of the aircraft above the terrain directly below it, to be able to activate certain features such as flare mode, or changes flight laws, elevator trim, auto thrust etc. Even a dinosaur like the 737NG has such RA dependent features.
Such features would not work correctly if the terrain half a mile before the threshold was significantly higher or lower than the runway threshold.
I remember in a distant past flying ILS approaches in aircraft that did not even have a RA, but the aircraft I now fly prohibits ILS approaches if both RA are U/S.
Last edited by Gilles Hudicourt; 6th Nov 2017 at 11:47.
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Italics are mine
Gilles Hudicort wrote
"12) The report failed to indicate if the crew selected a LOC05 in the FMS (it's a MCDU), and if they manually entered a corrected altitude at the FAF in the FMS, or if they just computed it for the FAF without changing the FMS provided FAF (uncorrected) crossing altitude. You would enter it in the MCDU at time of briefing, and then the PF checks the MCDU data entry including this change.
13) The report states that the crew computed a corrected MDA of 740 feet. But the report fails to indicate if the crew entered that corrected MDA in the FMS or the regular MDA."All part of the briefing after entering it in the MCDU and on a Non-Precision approach you add the 50 foot additive. PF cross checks all the data entry into the MCDU as part of his approach briefing.
The TSB report said the pilots did brief the approach, so these entries into the MCDU would have been done at that time, and cross checked by the PF. . DME would be set up to verify FAF passage too, and LOC up on PFD for raw data info. All standard SOPs.
from the TSB report;
"Air Canada’s Airbus A320 Quick Reference Handbook was revised to include the FPA and chart of approach altitude corrections for cold temperatures. The chart was designed to identify the applicable altitude correction (in 100-foot increments) to be added to the FAF and the degree correction to be added to the FPA based on the approach altitude height above the aerodrome and the temperature in degrees Celsius. The Quick Reference Handbook also includes a chart for the cold temperature corrections for the MDA. The investigation determined that the FPA calculated by the flight crew was in accordance with the QRH." which included the cold temperature corrections for FAF and MDA .
I find it hard to believe that Gilles would think none of this was done.
Finally, as stated in the TSB report,
"For a flight in FPA guidance mode, Air Canada’s practice was that, once the aircraft was past the FAF, the flight crews were not required to monitor the aircraft’s altitude and distance from the threshold, nor to make any adjustments to the FPA."
At Air Canada, the use of the distance/altitude table on the Jeppesen chart as a monitoring tool is not cited during pilot training for LOC/non-precision approaches"
Last Wx report was;
"wind 340°T at 22 knots, with gusts at 28 knots, visibility ¾ sm in light snow and drifting snow, broken cloud at 700 feet AGL, overcast cloud at 1000 feet AGL, temperature −6 °C, dew point −6 °C, and altimeter 29.62 in. Hg."
They were busy with that kind of weather..
So I doubt they would have been cross checking DME versus altitude inside the FAF, but that is speculation on my part.
Gilles Hudicort wrote
"12) The report failed to indicate if the crew selected a LOC05 in the FMS (it's a MCDU), and if they manually entered a corrected altitude at the FAF in the FMS, or if they just computed it for the FAF without changing the FMS provided FAF (uncorrected) crossing altitude. You would enter it in the MCDU at time of briefing, and then the PF checks the MCDU data entry including this change.
13) The report states that the crew computed a corrected MDA of 740 feet. But the report fails to indicate if the crew entered that corrected MDA in the FMS or the regular MDA."All part of the briefing after entering it in the MCDU and on a Non-Precision approach you add the 50 foot additive. PF cross checks all the data entry into the MCDU as part of his approach briefing.
The TSB report said the pilots did brief the approach, so these entries into the MCDU would have been done at that time, and cross checked by the PF. . DME would be set up to verify FAF passage too, and LOC up on PFD for raw data info. All standard SOPs.
from the TSB report;
"Air Canada’s Airbus A320 Quick Reference Handbook was revised to include the FPA and chart of approach altitude corrections for cold temperatures. The chart was designed to identify the applicable altitude correction (in 100-foot increments) to be added to the FAF and the degree correction to be added to the FPA based on the approach altitude height above the aerodrome and the temperature in degrees Celsius. The Quick Reference Handbook also includes a chart for the cold temperature corrections for the MDA. The investigation determined that the FPA calculated by the flight crew was in accordance with the QRH." which included the cold temperature corrections for FAF and MDA .
I find it hard to believe that Gilles would think none of this was done.
Finally, as stated in the TSB report,
"For a flight in FPA guidance mode, Air Canada’s practice was that, once the aircraft was past the FAF, the flight crews were not required to monitor the aircraft’s altitude and distance from the threshold, nor to make any adjustments to the FPA."
At Air Canada, the use of the distance/altitude table on the Jeppesen chart as a monitoring tool is not cited during pilot training for LOC/non-precision approaches"
Last Wx report was;
"wind 340°T at 22 knots, with gusts at 28 knots, visibility ¾ sm in light snow and drifting snow, broken cloud at 700 feet AGL, overcast cloud at 1000 feet AGL, temperature −6 °C, dew point −6 °C, and altimeter 29.62 in. Hg."
They were busy with that kind of weather..
So I doubt they would have been cross checking DME versus altitude inside the FAF, but that is speculation on my part.
Last edited by Retired DC9 driver; 6th Nov 2017 at 18:00.