Air Inuit DHC8 March 30th, 2024

[nobody23]

tsb.gc.ca/eng/medias-media/deploiement- ... 40405.html

[cdnavater]

Bad link

[J31]

https://www.wingsmagazine.com/air-inuit-kangiqsujuaq/

[Donald]

Final report is out, lots to unpack from this one:

https://www.tsb.gc.ca/eng/rapports-repo ... q0027.html

[Dias]

If they stopped putting berms on the ends of runways there would be less accidents involving aircraft hitting them.

[cdnavater]

If they stopped putting berms on the ends of runways there would be less accidents involving aircraft hitting them.

Did you read the report, they touched down short of the runway and also below the runway elevation, it was not a raised berm.


“Using an area just beyond the threshold as an aiming point placed the aircraft on a descent path leading to a touchdown before the runway threshold. The descent was not stopped owing to the effects of a downdraft. As a result, the touchdown occurred approximately 220 feet before the threshold, the wheels struck the mound below the runway level, and the left landing gear fractured”

[Donald]

Operating an aircraft at its performance limit for the runway.

Shooting an approach with visibility below charted limit.

Configuring final landing flap very late.

Aiming to touchdown at a point where the main gear hit prior to the threshold.

Intentionally flying the approach below glide slope.

Low experience level for the FO.

Lots of holes in this Swiss cheese.

[Canoehead]

It's too bad this report focuses so much on what happened in the end (airplane flies low, airplane contacts short of runway, landing gear fails), and not so much on the factors, casual, human, technical and otherwise, that got them to that point. Why did the AP deviate so much? No mention of testing the AFCS or the ADCs. Coupled VNAV or not?

Unless I'm missing something, no mention of it being a line training flight (that's a pretty big deal here I think). No mention of charted vis and what made them do a PMA (I don't have a plate for that approach); what are the PMA procedures for the company/fleet? AP, flap & prop configuration/limitations? Verbal callouts made by crew? (God forbid we publish any sort of transcript... someone might be offended).

The crew "....completed a PMA approach briefing for the area navigation approach..." Really? That's it? I don't understand why so many aspects of these TSB reports are glossed over with one usual focal point that gets beat to death.

Details matter. Another disappointing report from the TSB.

PS - They're called Power Levers, not "throttle".

[goingnowherefast]

I was really surprised not to read anything about visibility, or airport infrastructure/approach visual aids.

Gotta touchdown in this unmarked TDZ, but does the approach VNAV bring the plane there? Does the APAPI bring the plane to flare in an appropriate spot for the intended touchdown point?

Provide the pilots with zero guidance on getting to the flare point and touchdown point, then there's a good chance they're going to botch it when the visibility is crap.

Great, the SOP was amended to say abeam the wind sock. But it's night, and the windsock light is buried in snow. I guess we just go flying anyway, and learned nothing?

Glad we just blamed the pilots and didn't even discuss the lack of airport infrastructure that leads to these decisions.

[Donald]

It's almost like "pdw" wrote this TSB report.

[pelmet]

It's almost like "pdw" wrote this TSB report.

Haven't read is yet. But I did warn TSB Tasker a few years back to do his best to ensure that the TSB did not do diversity hiring that would lower safety standards of accident reporting and therefore, aviation safety overall. I doubt that the TSB, as molded by the politicians, as voted in by many people on this very forum, took my advice.

[goingnowherefast]

Mechanical turbulence can certainly create difficulties on approach. It's much more difficult to detect the problems when the visibility is crap, there is no TDZ markings and useful vertical guidance.

Jazz and Porter land a faster plane on a similarly short runway (albeit paved). They have excellent TDZ markings.

[Old fella]

It's almost like "pdw" wrote this TSB report.

Haven't read is yet. But I did warn TSB Tasker a few years back to do his best to ensure that the TSB did not do diversity hiring that would lower safety standards of accident reporting and therefore, aviation safety overall. I doubt that the TSB, as molded by the politicians, as voted in by many people on this very forum, took my advice.

To quote Buz Luhnmann 1999:

“Be careful whose advice you buy, but be patient with those who supply it
Advice is a form of nostalgia. Dispensing it is a way of fishing the past from the disposal, wiping it off, painting over the ugly parts and recycling it for more than it's worth”

[pelmet]

It's almost like "pdw" wrote this TSB report.

Haven't read is yet. But I did warn TSB Tasker a few years back to do his best to ensure that the TSB did not do diversity hiring that would lower safety standards of accident reporting and therefore, aviation safety overall. I doubt that the TSB, as molded by the politicians, as voted in by many people on this very forum, took my advice.

To quote Buz Luhnmann 1999:

“Be careful whose advice you buy, but be patient with those who supply it
Advice is a form of nostalgia. Dispensing it is a way of fishing the past from the disposal, wiping it off, painting over the ugly parts and recycling it for more than it's worth”

Thanks Old fella......

In just the last couple of days, I have given what I feel is some valuable advice on fuel sampling based on actual experiences I have had such as here...

http://www.avcanada.ca/forums2/viewtopi ... 3#p1349613

and here(Big Pistons Forever seemed to think it was helpful).....

http://www.avcanada.ca/forums2/viewtopic.php?t=229698

People can decide whose advice they prefer for accident prevention by searching though our posts.

I will plan on reading this incident report next.

[pelmet]

OK, I read the report.

They were doing an RNAV approach to a 3500' runway at an airport located in rugged terrain. I have flown on the north coast of Quebec and it definitely has that.

The first thing is the weather. It was 1/2 mile in moderate snow and blowing snow in late March. Ceiling was at 400'. That means it was likely total whiteout conditions and a visibility at ILS minimums. There are no approach lights, just the runway end and edge lights. It can be extremely difficult to see the runway lights at all weather like this when it is daylight. Depth perception would be made worse as this runway does not have approach lights or even a PAPI. One would think that Air Inuit would have been pressing for something like that over the years as it can be great help(TSB should press for it too). Perhaps they put a blue line on the snow runways like in some other regions. Possibly, the runway was scraped enough to see gravel but usually, it will be 100% compact snow and very difficult to see in such conditions. While the report discusses the upslope terrain approaching the runway creating an visual illusion, it is quite possible all was white outside and this was irrelevant.

Then there is the worry about the length of the runway at 3500'. That does not seem really short for a Dash-8-300 but it is not long. The pilots in at the company in general were said to be concerned about runway length because the factored landing distance(which is shown on all Air Inuit flight plans) was close to the runway length. But I believe that factored landing distance is without reverse and those PW100 engines/props will have plenty of reverse if used to the maximum. Plus, they had a decent headwind component. Still, the company is now publishing the unfactored landing distance instead(that being said, I have seen those in emergency landing checklists and they seem unrealistically short and misleading as they came from maximum braking in ideal conditions by test pilots).

In the end, the pilots did something than has frequently been done up north(and perhaps elsewhere) in intentionally descending on short final to be below the 50' threshold crossing height that performance calculations use. We used to call it 'Dipping the PAPIs' and it was simply done to minimize the amount of overflown runway prior to touching down(Didn't we do that for short field landings in basic training?). But this technique on the larger turboprops up north was more important on aircraft like the HS748 that had no reverse and could be in trouble if the runway was more slippery than anticipated(and it is not unusual up north for runway conditions to be different and worse than reported - real world versus TSB/TC theoretical world).

Seeing as the vis and depth perception was poor, there were no PAPIs, and there was significant turbulence, it was not a wise idea to do this 'dipping' maneuver. That was proven as they encountered a significant downdraft on short final and touched down short of the runway which has a steep dropoff, meaning the bottom of the gear was below the runway elevation. One shouldn't be so paranoid about runway length that they are doing these maneuvers in poor conditions. Just be ready to use lots of reverse, if necessary. Even idle reverse on the PW100 gives loads of deceleration.

One has to be careful when trying to touch down very close to the threshold, as a misjudgment can lead to touching down short. One guy at a place I used to fly did that with a Maule many years ago. He was practicing a short field landing, touched down short, and discovered that there was a lip at the beginning of the paved runway and bent a gear leg aft. As a low time pilot, it was a good learning lesson for me that I still remember.

It is interesting that Air Inuit had an official policy of aiming for the abeam point of the windsock as the touchdown point on short runways as they are located at an ideal touchdown point on shorter runways(500' from threshold).

They report did not further discuss the flaps being lowered on very short final(perhaps after becoming visual) which seems to me was technically a very unstable approach. Not sure how it affected the flight.

[goingnowherefast]

IIRC, the Dash-8 100/300 series doesn't permit flap 35 "until landing is assured" (paraphrasing).

That leads to a lot of late flap selections in bad weather on short runways. A smart move would be to artificially move minimums up to 500ft AAE, so there's sufficient time for the flap to move and the approach to stabilize. Yeah, there will be more missed approaches, but crashed airplanes don't make much revenue either. Or send the -100 if it can land safely with flap 15, and just not deal with that problem.

Reverse isn't permitted on gravel runways. But now we're also into the discussion of if it's a compact snow runway, or a gravel runway. 100% compact snow runway condition brings another whole discussion on stopping distance.