Westjet CYHZ

[tbaylx]

Nobody said they didn't calculate landing distance, did they?

If whipline is calculating 8150' for a landing distance and the runway is 7700' long they either didn't do one or did it and failed to take into account contamination or tailwind.

In any case 7700' with a tailwind is a short runway for an -800, never mind snow on it. Should be setting off alarm bells for any -800 crew before even looking at a landing distance calculation.

[J31]

The LDA for runway 14 at YHZ is 7700 ft, but what about the fact that the touchdown point for an ILS is not at the threshold? On a light twin you can chop and drop once you're visual (within reason), but what about the big guys? With a stabilized approach following the glidepath right to the ground, the touchdown point is quite a ways down the runway. For any of the heavy metal, does this always get factored in when considering if you're gonna get stopped before the end?

A stabilized 3 degree ILS will put most aircraft touching down about 1500 from the beginning of the runway. Landing performance programs normally take that into account.

From a Navajo to Airbus 380 the accepted normal is a stabilized approach with vertical guidance all the way to touchdown. Thus chopping and dropping off an ILS is not recommended.

[HiFlyChick]

From a Navajo to Airbus 380 the accepted normal is a stabilized approach with vertical guidance all the way to touchdown. Thus chopping and dropping off an ILS is not recommended.

You're right, of course, and with the profusion of 703 accidents I shouldn't suggest it

[HiFlyChick]

Rwy 5-32 was NOTAM closed. Westjet does not do LPV approaches with the 737.

Sorry - I was thinking of the RNAV 32... There's been so many storms here lately that I can't keep track of one mess of crappy weather from another!

What's so concerning is the mindset that diversion, even under such bad conditions, isn't an option. I've heard many discussions about whether operators should upgrade to WAAS or Halifax should upgrade to 4 ILSes, and in the end, if operators don't want to do the costly upgrade then they have to be good with going elsewhere. That in itself might motivate Halifax to upgrade to ILS on 32 and 05. It might not, but then they also have to accept the loss in business.

Is this a lack of decision making skills in general, or an increase in pressure from the operators to get in? I assume that by the time someone makes captain on a 737 (or 747 in the case of last year's accident) that the employer won't be so quick to fire him based on the occasional diversion in terrible weather... or is that naivete on my part?

[daedalusx]

What's so concerning is the mindset that diversion, even under such bad conditions, isn't an option. I've heard many discussions about whether operators should upgrade to WAAS or Halifax should upgrade to 4 ILSes, and in the end, if operators don't want to do the costly upgrade then they have to be good with going elsewhere. That in itself might motivate Halifax to upgrade to ILS on 32 and 05. It might not, but then they also have to accept the loss in business.

Apparently it was looked into and it would be very challenging to put ILSes on all 4 due to terrain/obstacles.

WAAS is a pipedream for airline operators due to obvious cost/benefits.

[J31]

It is very hard to show a return on investment upgrading runways and approaches. So I do not think Halifax will consider an ILS on 5 or 32 when a LPV approach gets you down to 200-250 ft decision altitude right now.

Conversely building stores and restaurants in terminals generates revenue. That is the cold hard truth about the capitalistic society.

Air operators have do decide on how to equip their aircraft and accept the operational limits. Diversions are part of the cost of doing business.

Westjet has good policies, procedures, and tools to assess whether to land or divert. I will wait for the report to comment.

[daedalusx]

It is very hard to show a return on investment upgrading runways and approaches. So I do not think Halifax will consider an ILS on 5 or 32 when a LPV approach gets you down to 200-250 ft decision altitude right now.

Conversely building stores and restaurants in terminals generates revenue. That is the cold hard truth about the capitalistic society.

Air operators have do decide on how to equip their aircraft and accept the operational limits. Diversions are part of the cost of doing business.

Westjet has good policies, procedures, and tools to assess whether to land or divert. I will wait for the report to comment.

Using OPT, Talpa numbers for Wet/Dry snow over 1/8in/Medium and 10 kts tailwind, no gust, 60-63T WT. I get max auto brake 7950-8250FT which can be reduced to 6900-7100 using Good to Medium braking action but you’d have to be 100% certain of the RSC or else you will go off at the end.

It would be interesting to compare aerodata performance numbers with Boeing OPT/Talpa. I’d be very interested to know what the crew inputted and what the TLR gave them, which metar/atis they used, did they carry a bit of extra speed on the approach due to gust factor, etc.

[goingnowherefast]

Do WJ crews get questioned on diversions?

Recently I did a pretty abnormal and expensive diversion (I don't work for WJ). About 2 short simple questions from management was all that was asked. "did you consider the wx at ___insert more typical diversion airport___?" Managers just have to have some explanation to the higher ups why they're footing the bill for a diversion and loss of revenue.

My favourite line is "because the aircraft is not WAAS/LPV capable". Thus turning the tables back on the higher-ups who are in charge of spending the upgrade money for WAAS/LPV capability.

It's also quite tricky to figure out the cost/benefit of upgrading aircraft to WAAS/LPV. Asking "How many more landings will happen with WAAS?" is a tricky question to ask when you typically fly to airports with multiple ILS installations. Although, it doesn't take many diversions to pay for WAAS. What does a diversion cost, including re-accomodating the passenger travel, repositioning the aircraft, cancelled flights and lost revenue while the aircraft is delayed, what about the flights the crew was supposed to operate? How do you calculate the price of pissed off passengers that are going to book with AC next time? Many variables that are hard to quantify. WAAS is probably a big scary number for a 737, just guessing, ~$250,000? Easy to scare a bean counter with an accurate avionics price quote when comparing it to less concrete diversion "price" with all the subjective data and guesses.

Although running a plane off the runway also scares bean counters.

[Eric Janson]

Here's the future - this will all be integrated into the aircraft systems.

https://youtu.be/F5nw2Mt3I1I

[Eric Janson]

Do WJ crews get questioned on diversions?

Recently I did a pretty abnormal and expensive diversion (I don't work for WJ). About 2 short simple questions from management was all that was asked. "did you consider the wx at ___insert more typical diversion airport___?" Managers just have to have some explanation to the higher ups why they're footing the bill for a diversion and loss of revenue.

My favourite line is "because the aircraft is not WAAS/LPV capable". Thus turning the tables back on the higher-ups who are in charge of spending the upgrade money for WAAS/LPV capability.

In situations like this I just file a Commanders report explaining what happened.

It may be that the PR people need to have something to give to the press/passengers or anyone else asking about what happened on flight XXX.

I've never heard a word about any Diversions/Go-arounds/Extra fuel I have made/taken - that's how it should be.

[rigpiggy]

What's so concerning is the mindset that diversion, even under such bad conditions, isn't an option. I've heard many discussions about whether operators should upgrade to WAAS or Halifax should upgrade to 4 ILSes, and in the end, if operators don't want to do the costly upgrade then they have to be good with going elsewhere. That in itself might motivate Halifax to upgrade to ILS on 32 and 05. It might not, but then they also have to accept the loss in business.

Apparently it was looked into and it would be very challenging to put ILSes on all 4 due to terrain/obstacles.

WAAS is a pipedream for airline operators due to obvious cost/benefits.

Ahhh look at the airport, actually NS as a whole. The only reason why not having 4 ILS's is for economic reasons. Why would you put ILS's on 05, or 32 when they are only used maybe 5% of the time. That said the airport authority seems more interested in selling you crap than improving aircraft ops(stub to 14, high speed turnoff, a second rvr on button of rw14(call visual by windsor, but airport closed due to rvr<1600 on 23, etc....)

[pdw]

Best ever ‘tailwindgust discussion’ (on landing) !

[mbav8r]

Best ever ‘tailwindgust discussion’ (on landing) !

Might have been low level variable windshear, he says tongue in cheek hoping not to encourage a response

[FurHat]

Report out;

https://www.bst-tsb.gc.ca/eng/rapports- ... a0001.html

[notwhoyouthinkIam]

It just goes to show that we're all human and, no matter how much experience we have, we are all prone to making mistakes.

[Capt. Underpants]

Ahhh look at the airport, actually NS as a whole. The only reason why not having 4 ILS's is for economic reasons. Why would you put ILS's on 05, or 32 when they are only used maybe 5% of the time. That said the airport authority seems more interested in selling you crap than improving aircraft ops(stub to 14, high speed turnoff, a second rvr on button of rw14(call visual by windsor, but airport closed due to rvr<1600 on 23, etc....)

An ILS on 05 would have made this Westjet flight a non-event, and probably would have prevented the AC accident in 2015. Seems a worthwhile investment to me.

I agree 100% as to the fiscal motivations of the airport authority.

[Eric Janson]

My company uses the airbus Flysmart app that is installed on iPads mounted on the sliding windows.

We can easily calculate landing distances - and once the data is entered it is extremely easy to update if things like
surface wind change.

Under EASA landing distance calculations are mandatory for every landing.

Another feature is that it will report if any limits are exceeded - we would have been warned the tailwind exceeded the maximum allowed.

Tailwind landings on anything other than a dry runway should be done with extreme caution imho.

[FICU]

There are many handy apps for an ipad or phone that will calculate crosswind/RFI and tailwind components by punching in a few numbers.

They should be included as part of the suite for pilots with EFBs.

[notwhoyouthinkIam]

Even the most experienced of us make mistakes.

[rookiepilot]

It just goes to show that we're all human and, no matter how much experience we have, we are all prone to making mistakes.

Why is it on this forum, I so often read these words -- when it's a commercial accident -- regardless of the cause.

When it's GA, -- the comments lean to how stupid the "weekend warrior" was, regardless of the cause. Certainly I experienced those kind of trolls, after my accident which TSB investigated and acknowledged was mechanical failure! Facts don't matter in this cesspool.

Seems a different standard, just observing.

Mechanical is mechanical, weather is weather, and pilot error is pilot error.

[notwhoyouthinkIam]

Absolutely, but the difference between the average GA pilot and the average airline pilot is experience difference in the tens of thousands of hours.

The captain here had over 30,000 hours.

[rookiepilot]

Absolutely, but the difference between the average GA pilot and the average airline pilot is experience difference in the tens of thousands of hours.

The captain here had over 30,000 hours.

Reading this, the standard "stuff happens, nothing to see here" typically read after a major Canadian carrier incident, seems to be premature:

While waiting for buses, flight crew were busy coordinating with the company and the tower. The flight crew received an ACARS message from the maintenance controller to remove electrical power to the cockpit voice recorder (CVR) and flight data recorder (FDR) by pulling circuit breakers C7, C8, C9, and C10.Footnote 10 The flight crew pulled the circuit breakers specified in the maintenance message; however, on this aircraft, the actual CVR circuit breaker was located at D6. Therefore, the CVR continued to be powered and the recording of the approach and landing was overwritten.

Not the first time.

[notwhoyouthinkIam]

Sure, a failure of maintenance to perform in a stressful situation points to an issue that needs to be addressed.

The fact is, it’s being pointed out so that we can all learn and make changes to your prevent a reoccurance.

[pelmet]

Report out;

https://www.bst-tsb.gc.ca/eng/rapports- ... a0001.html

Finally finished reading the report. One has to shake their head when they see a training captain with 30,000 hours not pick up that they had so much of a tailwind or as it appears....any tailwind at all. On a 737-800, which seems to have a reputation of being more challenging to get to a stop, one would think that in wet snow conditions on a relatively short runway, they would be carefully checking the wind conditions. Perhaps he somehow mistakenly got in his mind earlier on that runway 14 had a headwind component and nothing was able to subsequently change that belief. It can be difficult to change a mistaken frame of reference sometimes.

As far as I'm concerned, the idea somehow the runway will not have poor braking when the conditions are reported as only a trace of snow with the temperature at zero and the visibility is down to 1 1/4(and sometimes down to 1/2)miles in frozen precip should be tossed, especially when the runway report is almost 40 minutes old. In active precipitation conditions, the runway report should be considered reliable for a very short period of time.

Of course it is likely to be poor braking and assuming anything better is highly risky on a performance limited runway. And the visual segment that the pilots get just prior to landing can be misleading. We had an incident one time in similar conditions where the view presented to the pilots was mostly dark asphalt transitioning to snow accumulation close to the the runway edges. The runway appeared as mostly wet. It was but it was wet slush with snow around the edges of the runway. The pilots were looking at bare runway through the clear slush. I know it sounds odd, but perhaps the runway edges tend to be slightly cooler and the snow doesn't melt quite as fast. Anyways, beware of a runway in wet snow conditions that appears bare and wet with a transition to snow around the edges(different in this case where there it was reported that there was an 20 foot wide strip of intentionally unplowed snow at the runway edges that was relatively deep).

Westjet itself seems to be well aware of slippery runway hazards as the report says that they have an in-house publication called an Active Conditions Modification Table as part of a procedure requiring the pilots to use a more conservative runway condition value than what is reported.

Obviously, the unecessary increased approach speed just made things much worse. One would think that the pilot would have at least selected the autobrakes to Max to show awareness of the threat of a short runway for type in these conditions(although that apparently would not have helped), especially when the approach speed is over 160 knots, which should be setting off some alarm bells.

I have always been suspicious of this idea of good braking in thin slush condition(based on falling on my ass few times while walking in such conditions) and brought the question up a few years ago in the thread linked below. People seemed confident in their replies and perhaps that was their experience. But I would assume the worst, especially in active conditions and on an ungrooved runway.

viewtopic.php?f=54&t=110996&p=977586&hi ... sh#p977586

Here is an important quote from the report...."When the TSB investigators arrived on scene a few hours after the occurrence, the runway conditions had changed. The investigation was unable to determine the actual conditions at the time of the overrun. However, the difference in braking action between a trace, and greater than a trace, of wet snow varies from “good” braking to “medium to poor” braking. This shows a small change in runway condition can have a great variance in braking."

Another thing I think can be useful is a briefing reminder in such conditions to resist the habit of automatically reducing full reverse thrust when hearing the 60 knot call as happened in this incident. It is done so often, that it seems to be an automatic response and I have read several reports, such as this one, where the reverse is cancelled just when it is needed the most. And then a few seconds later, the pilot is desperately trying to spool up the engines again to get as much reverse thrust(the only slowing down option left) as possible while standing on the brakes with full anti-skid rendering them mostly ineffective.

The best bet would have been to continue the originally planned approach to runway 05(if allowed) with minimums slightly higher than the ceiling and hope to get the required visual references.