Halifax crash report coming Thursday

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TeePeeCreeper
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Re: Halifax crash report coming Thursday

Post by TeePeeCreeper »

AuxBatOn wrote: Fri Dec 14, 2018 9:21 pm Gilles, you are a real piece of work!!!

Really? Compared to ATC China or what have you not, Gilles seems to be well rounded and grounded as far as what he is seeking... do you oppose knowing what his freedom of information act entails or might uncover?
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Gilles Hudicourt
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Re: Halifax crash report coming Thursday

Post by Gilles Hudicourt »

I received the DFDR Download and Analysis report for the Air Canada accident in Halifax.

It does not answer most of the questions I had, but it does answer some.

The DFDR report does mention that the accident aircraft had no GPS, which the Final TSB report does not.
The pilots had manually tuned the Halifax VOR on #1 NAV and the DME for the approach on #2 Nav. It does not say if the crew ever used that information.

The actual position of the aircraft as depicted on the TSB report (graph) is based on a cross reference of the IRS, FMS positions (from the Aircraft) and the SSR Ground RADAR. The Aircraft DME, although available, was not used in the calculation.

The path depicted on the graph was computed with the aircraft's barometric indicated altitude, mathematically compensated for QNH and temperature, something they call a geopotential altitude, so the expected true altitude. They further cross referenced that altitude it with the Radio Altimeter Height, which was compensated for terrain height for the last 100 feet. The whole thing was smoothed out using a 3-point moving average.

The report does not state how the pilots determined the Final Descent point (FMS, DME or NDB) nor does it state if the NDB was ever tuned and monitored for station passage.
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Jet Jockey
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Re: Halifax crash report coming Thursday

Post by Jet Jockey »

Wait!

You are saying the VOR freq was tuned on NAV 1 during the approach?

Was the DME on NAV 2 on hold or they basically never used NAV 2 for reference/guidance for the approach?

I thought they were doing a LOC approach?
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Gilles Hudicourt
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Re: Halifax crash report coming Thursday

Post by Gilles Hudicourt »

The A320 series aircraft can tune in the ILS or Localiser plus two NAVs at the same time. The primary was tuned to the LOC frequency (109.9), and the two NAVs were tuned to the Halifax VOR(115.1), and on 109.1 which was the DME frequency indicated on the altitude/distance box of the LOC approach.

When an ILS or LOC approach is selected in the FMS, the FMS will automatically tune the ILS frequency and it will be displayed on the Primary Flight Displays of both pilots, along with the collocated DME, if there is one.

If the DME associated with the approach is on another frequency, as was the case in this approach, that other frequency must be manually tuned in the NAV page of the FMS and it is displayed (if selected with the VOR/NDB buttons), in one of the bottom corners of the Navigation display.
In this case they had Halifax VOR in the bottom left, and the DME for the approach on the bottom right corner of the ND.

Because this aircraft had no GPS and the FMS could have been subject to a small position error, I would have certainly used the DME and not the FMS to determine the Final Descent point. The report was silent on how this crew determined the descent point, but at least I now know that the DME was tuned.
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pelmet
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Re: Halifax crash report coming Thursday

Post by pelmet »

After finally reading the report, one has to wonder if the crew(or the PIC) were assuming that the FPA would guide them to the TDZ just like a glideslope or VNAV(or APPR) equivalent. I wonder if the TSB asked them that question. They had no PAPIs in view making it very difficult to judge whether or not they were on a desired approach path. Very tricky situation in poor visibility. Even on a good night, with clear skies and no wind, there could be difficulties visually judging a proper glidepath with no Papis.
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swordfish
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Re: Halifax crash report coming Thursday

Post by swordfish »

All these words and opinions - millions - for an accident that was clearly pilot error. Too hard for the TSB to lay the blame squarely on the crew.
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Capt. Underpants
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Re: Halifax crash report coming Thursday

Post by Capt. Underpants »

swordfish wrote: Mon Aug 26, 2019 10:12 pm All these words and opinions - millions - for an accident that was clearly pilot error. Too hard for the TSB to lay the blame squarely on the crew.
What a crock. This accident was a systemic failure on many levels. The TSB did an excellent job of pointing that out. Are you one of those "CRM is for sissies" people too?
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swordfish
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Re: Halifax crash report coming Thursday

Post by swordfish »

??? They flew the plane into the ground, and it was "systemic failures"??

Get a grip.
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iflyforpie
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Re: Halifax crash report coming Thursday

Post by iflyforpie »

swordfish wrote: Tue Aug 27, 2019 9:34 am ??? They flew the plane into the ground, and it was "systemic failures"??

Get a grip.
They did blame the pilots. There were also other factors in the crash.

What the hell do you want? A one page report that says:

THE PILOTS DID IT!!!

50 lashes with a wet noodle? Lifetime ban from flying? An inscription on the wall of shame?

Look, we tried your way for 50 years and all we wound up with is experienced and lucky pilots who figured they were superior to the ones that crashed right up until the moment they crashed.

Instead, errors that were made here will be trapped by remedial training, revised procedures, and better infrastructure and aids; those who read the report like myself will be more aware of falling into traps in FMS equipped aircraft without a fixed-in-space vertical mode.

It’s part of the reason why we are still talking about this crash 4 years later rather than any of the dozens upon dozens more airliner crashes that would have happened by now in the bad old days.
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Geez did I say that....? Or just think it....?
Capt. Underpants
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Re: Halifax crash report coming Thursday

Post by Capt. Underpants »

swordfish wrote: Tue Aug 27, 2019 9:34 am ??? They flew the plane into the ground, and it was "systemic failures"??

Get a grip.
I have a grip. I do flight safety for a living and am very proud of the results that have been achieved by the team I've worked with. One reason we have been successful is by looking beyond finger pointing.

Did this crew make errors? Yes, of course. The report is clear about that. The report is also clear about the contributing factors that led to them being in that state in the first place. There are very real phenomena like confirmation bias that play a major role in events like this one. I've seen over 100 FPA approaches flown in an A320 simulator using the same SOPs and not once did the aircraft end up significantly low on the approach when the procedure was flown in accordance with the training. I know for a fact that not checking the altitude inside the FAF was not a single error, it was done that way all the time at AC. That doesn't make it right, but to ignore such factors is ... well ...
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pelmet
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Re: Halifax crash report coming Thursday

Post by pelmet »

Capt. Underpants wrote: Tue Aug 27, 2019 10:18 am I've seen over 100 FPA approaches flown in an A320 simulator using the same SOPs and not once did the aircraft end up significantly low on the approach when the procedure was flown in accordance with the training.
I wonder about the sim scenario. If you have flown many of them, then you will know that there are differences between the sim and the airplane. And different sims from different manufacturers can handle differently from each other.

I have seen in a sim where no change in rudder input during the entire takeoff roll results in the desired trajectory along the runway being maintained such as in a crosswind. It is a computer thing.

I wonder how accurate the winds on approach are in a sim setup for FPA. Can the random so-called “perturbations” of turbulence and varying winds which can result in a parallel trajectory really be simulated? Is it the same in all sims?

Perhaps there is a greater tendency for it all to work out positioning-wise in the sim if the initial trajectory was properly set up. That could mislead crews into thinking that FPA will always get you into the desired position over the threshold if you started out properly.

Then some similar experiences on the line where the ‘perturbations’ all mostly cancelled themselves out reinforced that view when in fact, there could be occasional times where it doesn’t work out.

It would be interesting to hear from some experienced guys on real world versus simulator experiences using FPA and its accuracy in placing the aircraft in a nice position for landing with no further or only very minor further inputs required for the last portion of the descent once the AP is disconnected.
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Capt. Underpants
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Re: Halifax crash report coming Thursday

Post by Capt. Underpants »

Yes there are differences, but as you know the simulator will only fly to the programmed performance profile. This one was never identified in any differences briefing I was involved with, and I've used about a dozen different simulators in numerous locations. The Airbus simulators are excellent overall because they have mountains of captured flight data and systems data to build on. As with the 737 MAX MCAS situation, you can't train it if you don't identify it.
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swordfish
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Re: Halifax crash report coming Thursday

Post by swordfish »

There must be HUNDREDS of npa's flown every day by 320 (-family) that don't end up in the same predicament. Systematically beating the odds of failure.

I am not proposing or pontificating punitive measures for the crew. The preliminary report that John Lee delivered to NATA a year ago alluded to all the corrolary factors but nowhere did they lay the blame for the event squarely where it belonged.

That is what I object to.
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Heliian
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Re: Halifax crash report coming Thursday

Post by Heliian »

It's a tale as old as time.

Pilots pushed it and lost. Blame whomever you want, it won't change what happened and it won't stop someone else from doing it.
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pelmet
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Re: Halifax crash report coming Thursday

Post by pelmet »

Heliian wrote: Tue Aug 27, 2019 4:10 pm It's a tale as old as time.

Pilots pushed it and lost. Blame whomever you want, it won't change what happened and it won't stop someone else from doing it.
Possibly. But I am just trying to get deeper into what the thought process was. Was there an assumption by the crew that the descent trajectory would take them to a proper position like a glide slope all the time, most of the time, perhaps they knew there was no guarantee of proper positioning and just got caught up in all the goings on of the approach and things happened more quickly than expected, etc.

If the Airbus sims never show that ‘perturbations’ might lead to deviations due to sim not being able to simulate randomness of perturbations, it would be useful for pilots to be informed of this.

One would think that with winds frequently decreasing significantly on approach, that FPA guidance would frequently be inaccurate.

Anybody have actual experiences they want to share.
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pelmet
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Re: Halifax crash report coming Thursday

Post by pelmet »

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goingnowherefast
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Re: Halifax crash report coming Thursday

Post by goingnowherefast »

Didn't know that was allowed in Canada. Can't imagine ACPA being happy about it either.
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Capt. Underpants
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Re: Halifax crash report coming Thursday

Post by Capt. Underpants »

This needs to be challenged all the way to the SCOC, and the TSB and TC should be the ones who take that challenge forward.
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ReserveTank
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Re: Halifax crash report coming Thursday

Post by ReserveTank »

pelmet wrote: Wed Nov 20, 2019 6:05 pm CVR might be made public....

https://www.msn.com/en-ca/news/canada/p ... spartandhp
As well it should be.
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boeingboy
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Re: Halifax crash report coming Thursday

Post by boeingboy »

What possible information could they need when the transcripts are available?
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