Halifax crash report coming Thursday

[Jimmy2]

The autopilot disconnect issue is irrelevant because had they disconnected it at MDA how exactly would that have improved the situation?

It goes towards intent. You reach the MDA, the PNF calls minimums, field in sight (or lights in sight is what AC was using apparently), PF says 'Lights in sight. Landing', autopilot goes off. This is the way it always happens. But not in this case. Why? Why decide to let the autopilot handle it for a while longer and see how this plays out?

[Rockie]

The autopilot disconnect issue is irrelevant because had they disconnected it at MDA how exactly would that have improved the situation?

It goes towards intent. You reach the MDA, the PNF calls minimums, field in sight (or lights in sight is what AC was using apparently), PF says 'Lights in sight. Landing', autopilot goes off. This is the way it always happens. But not in this case. Why? Why decide to let the autopilot handle it for a while longer and see how this plays out?

What makes you think it was intended? The call by the way was "Lights Only".

[Bede]

Sorry if I missed it in the report or this thread, but aren't their PAPI's on that runway. Seeing 4 red lights may be a clue that something is wrong. Wouldn't that raise some red flags before CFIT?

[CpnCrunch]

Sorry if I missed it in the report or this thread, but aren't their PAPI's on that runway. Seeing 4 red lights may be a clue that something is wrong. Wouldn't that raise some red flags before CFIT?

From the report:

"In this occurrence, the flight crew did not see the PAPI lights during the approach."

[Rockie]

Sorry if I missed it in the report or this thread, but aren't their PAPI's on that runway. Seeing 4 red lights may be a clue that something is wrong. Wouldn't that raise some red flags before CFIT?

1/2 mile visibility with a MDA over 300 feet above threshold elevation. When do you think the threshold never mind the PAPI would be visible to the crew? All perfectly legal of course.

[pelmet]

The autopilot disconnect issue is irrelevant because had they disconnected it at MDA how exactly would that have improved the situation?

It goes towards intent. You reach the MDA, the PNF calls minimums, field in sight (or lights in sight is what AC was using apparently), PF says 'Lights in sight. Landing', autopilot goes off. This is the way it always happens. But not in this case. Why? Why decide to let the autopilot handle it for a while longer and see how this plays out?

Why not? I question if you are actually an airline pilot with experience on a modern aircraft if you think that the autopilot is ALWAYS disconnected at the MDA. There can be good reasons to leave it on.

[ditar]

Assuming it's within the limitations of the aircraft, it's often a good idea to leave the autopilot on a little while longer when transitioning to visual cues below MDA/DH. In poor visibility conditions it's easy to drift above or below the glide path otherwise.

[confusedalot]

This is what I was trying to get at. You've got enough shit to deal with at minimums with crappy visibility, so why not leave the autopilot on for a few more seconds to sort things out and give yourself a break? Assuming of course that the equipment limitations allow you to do that. Never flew an airbus, somehow I am wondering about an airbus limitation that says autopilot off at minimums. Hell, they are more advanced than boeings. But hey, I don't know, and I don't want to bug my buddies and ask them. But I probably will someday.

And there is the nagging question about what they actually saw at or near minimums to make a decision to continue.

It can happen to anyone, nobody is above error.

[tailgunner]

What I expected to see in the report and did not, was the difficulty the crew would have seeing due to the crab from the crosswind. The aircraft nose would have been displaced upwards of 5-15 degrees off of centreline to the left. The Captian ( PF) would have to look across the window/glareshield/centre window frame too aquire the lights. More added difficulty

[stef]

Isn't saying that monitoring height vs distance wasn't written in SOP a little like saying "don't crash the plane" wasn't written into SOP?

Do we really need some new laws to be written and SOPs rewritten to keep us from crashing guys? Come on.

[teacher]

Sorry if I missed it in the report or this thread, but aren't their PAPI's on that runway. Seeing 4 red lights may be a clue that something is wrong. Wouldn't that raise some red flags before CFIT?

1/2 mile visibility with a MDA over 300 feet above threshold elevation. When do you think the threshold never mind the PAPI would be visible to the crew? All perfectly legal of course.

In my professional opinion the pilots always have the last say, true. However in this case the regulations, airport and aircraft equipment led them down the garden path to a place where they made a decision that seemed correct at the time, was deemed not, initiated a go around and all within a very short time and ended up being too late.

Had the regulations been such that an approach into weather where at minimums you cannot see the runway was NOT ALLOWED this would not have happened. Had the lights been on strength 5 and been proper approach lighting they may have had better depth perception and runway orientation and noticed they were too low.

A few things led them to this spot and it's not as easy as "they screwed up".

Sadly not much has changed regulation wise but procedurally at AC it has along with GPS being installed so VNAV coupled GPS approaches can be flown when available rather than Non precision approaches.

[Jet Jockey]

Simple question...

Can the Airbus 320 pilots on this forum tell us what is the minimum altitude AGL for autopilot use is when conducting a NON precision approach?

[Rockie]

Simple question...

Can the Airbus 320 pilots on this forum tell us what is the minimum altitude AGL for autopilot use is when conducting a NON precision approach?

319/320/321 minimum height use for autopilot on a non-precision approach is the applicable MDA.

[Jimmy2]

One thing about the good old dive and drive method of conducting a non-precision approach is that it requires a positive action to start descent below the MDA for landing. For a constant descent angle approach you don't have to do anything to go below the MDA other than sit there and watch the autopilot take you through it. Human nature being what it is a person is more likely to do something if it requires no action on their part than if it requires a deliberate action.

Another thing about dive and drive is it makes the amount of time you have available to identify the runway or approach lights a bit longer. You are leveled off and have time to look out and wait for lights to appear. This is especially true when forward visibility is limiting and not ceiling. CDA means you have to make a split second decision about what you see similar to an ILS. Personally I think that if the visibility is right down you are more likely to be able to successfully land using dive and drive. But the world has decided that CDA is safer so that is moot, and I agree that seeing the lights at the last minute and diving for the runway has it's own big risks.

[Rockie]

You're right Jimmy. Non-precision approaches were originally designed as a dive and drive type approach where the pilot levelled at MDA and approached the runway watching the sight picture develop. In large aircraft though it was determined long ago that it was much safer from a CFIT point of view to conduct them as a SCDA. Unfortunately that doesn't negate the limitations that you point out.

In the not too distant future I hope conventional NPA's lacking vertical guidance will be rendered obsolete and disappear, and all our lives will be much simpler and safer.

[Donald]

Had a chuckle today hearing AC request the NDB approach, while we did the LPV approach in a 20+ year old Boeing.

[Rockie]

Had a chuckle today hearing AC request the NDB approach, while we did the LPV approach in a 20+ year old Boeing.

Colour me green with envy....

I honestly don't get AC's aversion to WAAS. Seriously...I don't get it.

[Inverted2]

Hard to believe a major carrier like Air Canada is still flying around with aircraft with no GPS. Also hard to believe an airport with weather like YHZ doesn't have an ILS on each runway (they only have 4!)

[Jack Klumpus]

From airbus FCTM:
When the required visual conditions are met to continue the approach, the AP must be disconnected, the FDs selected off, Bird ON and continue for visual approach.

For those who say keep the auto-pilot on for a few more seconds and see how it goes. Perhaps in the old Navajo you did that up north. Not in big jets with hundreds of people behind you.

As for Rockie, you say AC SOP state not to change the FPA after the FAF. what are those distance vs altitude tables for then? Forget the yoyo, dme vs altitude at every mile. If indeed AC SOP say that, well that's a huge problem. I find that hard to believe.

What about wind changes, temperature differences? Say it's +50C, don't you correct from the charted? Howbout -50C?

I've flown the 320 in those conditions and you do not fly the charted angle, and you most certainly do make minor corrections to your FPA based on your distance vs altitude chart.

Looking at the Halifax LOC05 chart, you have the DME readout from 11.8 nm. You said after the FAF you don't touch the FPA? Why is there a 2.7 altitude check? If you're high you go around at 3.5 dme? You don't attempt to fix it?

[Jack Klumpus]

Rockie, you say AC SOP state not to change the FPA after the FAF. what are those distance vs altitude tables for then? Forget the yoyo, dme vs altitude at every mile. If indeed AC SOP say that, well that's a huge problem. I find that hard to believe.

Looking at the Halifax LOC05 chart, you have the DME readout from 11.8 nm. You said after the FAF you don't touch the FPA? Why is there a 2.7 altitude check? If you're high you go around at 3.5 dme? You don't attempt to fix it?

[Rockie]

Rockie, you say AC SOP state not to change the FPA after the FAF. what are those distance vs altitude tables for then? Forget the yoyo, dme vs altitude at every mile. If indeed AC SOP say that, well that's a huge problem. I find that hard to believe.

Looking at the Halifax LOC05 chart, you have the DME readout from 11.8 nm. You said after the FAF you don't touch the FPA? Why is there a 2.7 altitude check? If you're high you go around at 3.5 dme? You don't attempt to fix it?

You think I'm wrong about the SOP? It is not true that AC says to not monitor our progress on the way down from the FAF. Quite the opposite. But we do not correct after the FAF because there is no reliable displayed glide path to correct to, and we would just be destabilizing the approach. If it looks like it's not working out we go-around. That may change once the whole fleet is GPS equipped but that's up to them.

What are your thoughts about the approach ban, the role of approach lighting on required visibility for the approach and Canada's required visual references?

[KAG]

An unfortunate series of events lead this experienced crew to make this mistake. Its not one single thing, too east to say they screwed up. I hope we can all take something away from this and not let it happen to us.
Fly safe all.

[Jack Klumpus]

You think I'm wrong about the SOP? It is not true that AC says to not monitor our progress on the way down from the FAF. Quite the opposite. But we do not correct after the FAF because there is no reliable displayed glide path to correct to, and we would just be destabilizing the approach. If it looks like it's not working out we go-around. That may change once the whole fleet is GPS equipped but that's up to them.

What are your thoughts about the approach ban, the role of approach lighting on required visibility for the approach and Canada's required visual references?

Your SOP says monitor because the FCTM says so. How does it make sense that you do not correct after the FAF? Why do they publish a path angle for the approach? Isn't it so we follow that.

Reliable displayed glide path? You mean yoyo? Since when do you need something displayed in order to follow it? You have the distance vs altitude chart, isn't that reliable? Don't you follow that chart and call out the deviations from it?

Also, since you're an airbus guy, you can have the brick to use as a reference only. However table vs distance chart and adjust your FPA accordingly!

Forget the approach ban and all that for now. Answer me why is it that the distance vs altitude table isn't reliable for you guys to use and adjust your FPA according to that.

[Antique Pilot]

A short summary:

EJ says you can adjust the FPA as required.

GH says you can modify the FPV.

JK says the PF will adjust the FPA according to their path.

Rockie says Company SOP is to not adjust the FPA.

I assume that these are experienced Airbus pilots but possibly from different airlines. Interesting.

Let's say the weather was good enough to conduct a Managed NDB 05 approach at CYHZ but the winds with gusts, turbulence, etc, was exactly the same. Would the Managed NDB approach have put them in a better position to land at minimums as opposed to using the Selected FPA method? I am just trying to get a better understanding of the 2 methods of doing a NPA approach.

Thanks,
AP

[pdw]

winds with gusts, turbulence, etc

A "54kt" (gust) reference was included in this final report. If that is at surface (and not an "error") then at "750' broken" it's blowing much stronger sustained at FAF/740'msl than would be expected. As a 40-50degree left crosswind at MDA, this higher windspeed makes the snail-pace groundspeed between 0023 and 0030 (approx 11NM/7min) where-in this accident sequence had set up.