Westjet CYHZ

[pelmet]

Hi Aux,

The civilian airliner world is likely much different than the military world. After an infamous 737 crash in Cranbrook where the reversers were stowed for a go-around when a snowplow was sighted with subsequent re-deployment of one of them, all jet airliners were restricted from doing this anymore. That being said, it has happened(after all, it happened in a company of mine to a Douglas product and I have read of other incidents including a widebody where one did not stow again).

Bottom line for airliners with reversers, once deployed, you are riding it out regardless of what subsequently happens, and on almost any contaminated runway, they will be deployed quickly.

More info on the C-17 in terms of go-around options after thrust reverser deployment after landing would be interesting.

[AuxBatOn]

Hi Aux,

The civilian airliner world is likely much different than the military world. After an infamous 737 crash in Cranbrook where the reversers were stowed for a go-around when a snowplow was sighted with subsequent re-deployment of one of them, all jet airliners were restricted from doing this anymore. That being said, it has happened(after all, it happened in a company of mine to a Douglas product and I have read of other incidents including a widebody where one did not stow again).

Bottom line for airliners with reversers, once deployed, you are riding it out regardless of what subsequently happens, and on almost any contaminated runway, they will be deployed quickly.

More info on the C-17 in terms of go-around options after thrust reverser deployment after landing would be interesting.

Thanks Pelmet. I’ll try and dig it.

[GoinVertical]

Just a honest question: what do you do if you experience a brake failure after you deploy the thrust reversers? Ride it out?

Apply the emergency / parking brake that uses a different hydraulic system than the regular brakes.

I mean, total brake failure. Or is it something with 3+ levels of contingency?

Multiple brake assemblies and lines make that pretty unlikely barring a total loss of hydraulic fluid.

[GRK2]

Hi Aux,

The civilian airliner world is likely much different than the military world. After an infamous 737 crash in Cranbrook where the reversers were stowed for a go-around when a snowplow was sighted with subsequent re-deployment of one of them, all jet airliners were restricted from doing this anymore. That being said, it has happened(after all, it happened in a company of mine to a Douglas product and I have read of other incidents including a widebody where one did not stow again).

Bottom line for airliners with reversers, once deployed, you are riding it out regardless of what subsequently happens, and on almost any contaminated runway, they will be deployed quickly.

More info on the C-17 in terms of go-around options after thrust reverser deployment after landing would be interesting.

Thanks Pelmet. I’ll try and dig it.

While you're looking try the LAUDA B767 crash...not on landing, one deployed while airborne...not a happy ending, it's now practiced during training.

[Hugh Jasshole]

On a 737NG there is a mechanical squat switch on the right landing gear scissors. A bowden cable runs up the gear leg into the wheel well and terminates at a hydraulic valve with some electrical switches. Once this cable pulls the valve open, hydraulics can deploy the inner speed brakes on top of the wing. Also electrical switch on valve sends a signal to the PSEU to tell thrust reversers that aircraft is on ground and then the TR's can open. TR's and speed brakes cannot deploy unless right landing gear is compressed (on ground).

[172_Captain]

Assuming they’re guilt, what should the punishment be? Considering we’ve already decided that firing the pilots and lynching they’re family was the correct response for those two WS pilots that took out a light at YYZ. Clearly the punishment should fit the crime!

[telex]

[daedalusx]

Heavy tailwind/gust
Shitty runway surface condition
Shitty visibility and ceiling
On a -800 which doesn’t have the greatest reputation for its braking/landing performance
And they landed on the shortest runway ...

It doesn’t look like they tried to hold and wait, they just went straight for gusto. 15min before them there was an AC321 that diverted back to YUL, they didn’t even try doing the approach - you’d think it would have clued them in.

What the fu.ck where they thinking?

[plausiblyannonymous]

Heavy tailwind/gust
Shitty runway surface condition
Shitty visibility and ceiling
On a -800 which doesn’t have the greatest reputation for its braking/landing performance
And they landed on the shortest runway ...

It doesn’t look like they tried to hold and wait, they just went straight for gusto. 15min before them there was an AC321 that diverted back to YUL, they didn’t even try doing the approach - you’d think it would have clued them in.

What the fu.ck where they thinking?

Well, at least all of the wheels stayed on.

[SAR_YQQ]

Hey fellas, FWIW multi-engine RCAF pilots don’t ever consider a “go-around” after we have committed to applying TR, propellor reverse, speed brakes, etc. This is not manoeuvre we are trained to perform, nor is it authorized. If any of my pilots were to pontificate this technique, I would be making inroads towards removing their Wings and sending them to work at the CAOC.

Happy New Year.

[Victory]

Ah Halifax. The world's most dangerous airport for airliners.

[Eric Janson]

Just for my curiosity:-

Does dispatch not look at landing distance as part of the pre-departure paperwork?

Is there a requirement to compute landing distance at Canadian carriers?

My company uses the airbus flysmart software - very easy to use. Boeing must have something similar - I was using a laptop for Performance on the 757 in 2001.

[complexintentions]

Ho hum. Another winter in Canada, another runway overrun. Glad no one was hurt.

I sure wish I could find that thread with the guy going off about the superiority of Western carriers versus Asian ones vis a vis overruns...but I guess I can understand why he removed his comments!

[CFM Symphony]

On a 737NG there is a mechanical squat switch on the right landing gear scissors. A bowden cable runs up the gear leg into the wheel well and terminates at a hydraulic valve with some electrical switches. Once this cable pulls the valve open, hydraulics can deploy the inner speed brakes on top of the wing. Also electrical switch on valve sends a signal to the PSEU to tell thrust reversers that aircraft is on ground and then the TR's can open. TR's and speed brakes cannot deploy unless right landing gear is compressed (on ground).

One slight correction:

The 737NG TR can open at or below 10ft Radar Altitude. This is strictly a safety design in case the WOW switch fails, rather than a design promoting TR use in flight. FCOM 7.20.14

Cheers.
CFM

[YYZatcboy]

Just for my curiosity:-

Does dispatch not look at landing distance as part of the pre-departure paperwork?

Is there a requirement to compute landing distance at Canadian carriers?

My company uses the airbus flysmart software - very easy to use. Boeing must have something similar - I was using a laptop for Performance on the 757 in 2001.

Yes Dispatch in Canada (or the PIC) does but remember for landing performance the only numbers are Dry/Wet, unlike for takeoff where we have contamination levels.

Getting updated RSCs can be like pulling teeth at most airports in Canada. We often get the "nothing has changed so there is no requirement to provide an update" speech. Then when we insist the conditions are often markedly worse.

[brooks]

Is it just me or does Halifax have a rate of incidences/accidents as of late? I can recall a 747 going off the end on rwy 14 last year or something?

[altiplano]

Just for my curiosity:-

Does dispatch not look at landing distance as part of the pre-departure paperwork?

Is there a requirement to compute landing distance at Canadian carriers?

My company uses the airbus flysmart software - very easy to use. Boeing must have something similar - I was using a laptop for Performance on the 757 in 2001.

Yes Dispatch in Canada (or the PIC) does but remember for landing performance the only numbers are Dry/Wet, unlike for takeoff where we have contamination levels.

Getting updated RSCs can be like pulling teeth at most airports in Canada. We often get the "nothing has changed so there is no requirement to provide an update" speech. Then when we insist the conditions are often markedly worse.

What do you mean the only numbers you have for landing are dry/wet?

Maybe you should tell management to $pring for the tools and data for you to do your jobs safely.

Maybe leak it to CBC anonymously that you aren't provided with data for landing on winter runway conditions if that's indeed what you're saying.

[YYZatcboy]

Just for my curiosity:-

Does dispatch not look at landing distance as part of the pre-departure paperwork?

Is there a requirement to compute landing distance at Canadian carriers?

My company uses the airbus flysmart software - very easy to use. Boeing must have something similar - I was using a laptop for Performance on the 757 in 2001.

Yes Dispatch in Canada (or the PIC) does but remember for landing performance the only numbers are Dry/Wet, unlike for takeoff where we have contamination levels.

Getting updated RSCs can be like pulling teeth at most airports in Canada. We often get the "nothing has changed so there is no requirement to provide an update" speech. Then when we insist the conditions are often markedly worse.

What do you mean the only numbers you have for landing are dry/wet?

Maybe you should tell management to $pring for the tools and data for you to do your jobs safely.

Maybe leak it to CBC anonymously that you aren't provided with data for landing on winter runway conditions if that's indeed what you're saying.

As I said PRIOR TO DISPATCH (The question was "Does dispatch not look at landing distance as part of the pre-departure paperwork?") the only LEGAL numbers are for DRY/WET. This is the Dispatch Landing Field Length. The Inflight factored landing distance calculation can include contamination levels and different runway contaminants. But that is not the LEGAL dispatch field length prior to takeoff. Good airmanship of course dictates that contamination levels be taken into account prior to dispatch but that is NOT part of the Dispatch landing field length. We provide data in a Takeoff and landing report that has both sets of numbers, but again the legal ones for the Dispatch landing field length is only Dry/Wet.

I will grant that my post could have been clearer above.

Below are the relevant CAR/CASS references:

Dispatch Limitations: Landing at Destination and Alternate Aerodromes
* 705.60 (1) Subject to subsection (3), no person shall dispatch or conduct a take-off in an aeroplane unless
* (a) the weight of the aeroplane on landing at the destination aerodrome will allow a full-stop landing
* (i) in the case of a turbo-jet-powered aeroplane, within 60 per cent of the landing distance available (LDA), or
* (ii) in the case of a propeller-driven aeroplane, within 70 per cent of the landing distance available (LDA); and
* (b) the weight of the aeroplane on landing at the alternate aerodrome will allow a full-stop landing
* (i) in the case of a turbo-jet-powered aeroplane, within 60 per cent of the landing distance available (LDA), and
* (ii) in the case of a propeller-driven aeroplane, within 70 per cent of the landing distance available (LDA).
* (2) In determining whether an aeroplane can be dispatched or a take-off can be conducted in accordance with subsection (1), the following shall be taken into account:
* (a) the pressure-altitude at the destination aerodrome and at the alternate aerodrome;
* (b) not more than 50 per cent of the reported headwind component or not less than 150 per cent of the reported tailwind component; and
* (c) that the aeroplane must be landed on a suitable runway, considering the wind speed and direction, the ground handling characteristics of the aeroplane, and other conditions such as landing aids and terrain.
* (3) Where conditions at the destination aerodrome at the time of take-off do not permit compliance with paragraph (2)(c), an aeroplane may be dispatched and a take-off conducted if the alternate aerodrome designated in the operational flight plan permits, at the time of take-off, compliance with paragraph (1)(b) and subsection (2).
Dispatch Limitations: Wet Runway — Turbo-jet-powered Aeroplanes
* 705.61 (1) Subject to subsection (2), when weather reports or forecasts indicate that the runway may be wet at the estimated time of arrival, no air operator shall dispatch or conduct a take-off in a turbo-jet-powered aeroplane unless the landing distance available (LDA) at the destination aerodrome is at least 115 per cent of the landing distance required pursuant to paragraph 705.60(1)(a).
* (2) The landing distance available on a wet runway may be shorter than that required by subsection (1), but not shorter than that required by section 705.60, if the aircraft flight manual includes specific information about landing distances on wet runways.

745.61 Dispatch Limitations: Wet Runway - Turbo-Jet-Powered Aeroplanes

R745.61(2) - Dispatch Limitations - Wet Runway
A runway is deemed to be wet when there is sufficient moisture on its surface to cause it to be reflective. In this case, additional landing distances, required for dispatch, must be available. Most AFMs do not contain wet runway landing distances. Should an air operator wish relief from the 115% requirement, wet runway landing distances must be demonstrated to Transport Canada in accordance with a test program approved by Transport Canada.
If a flight has been planned to a dry destination and unforeseen precipitation makes the planned runway wet, the flight can continue so long as the aeroplane can stop on the runway available plus 15 percent.

[valleyboy]

Jeezus such a long thread with so much dissection to a simple overrun which will boil down to a basic chain of events. Seems that everyone wants to armchair quarterback events when there is an incident no matter how small it is. Decision making and human factors is the weakest link in aviation now. Even the max disasters would have been prevented if the human factor in pilot decision making had made the correct choices. The true tragic factor was the short comings of crew training. It was manageable if they had been given the information and training. Ironically everything falls to the lowest common denominator. Atlas is another example.

We can quote procedures and rules but crew actions at the event horizon still and will always dictate the outcome until aircraft become fully automated.

[L39Guy]

Is it just me or does Halifax have a rate of incidences/accidents as of late? I can recall a 747 going off the end on rwy 14 last year or something?

Yes, Halifax does seem to have an abnormally high number of incidents, some their fault, some not.
- the cargo aircraft that crashed during take-off using the Boeing performance laptop using the wrong figures, not their fault.
- the recent cargo aircraft that ran off the runway with a quartering tailwind; not their fault.
- the AC A320 that landed short, CYHZ and NAV CANADA partially at fault for inadequate runway lighting (the former) and a lack of an ILS (the latter) at an airport with a lot of crappy weather.

This whole thread is really making a mountain out of a molehill. Given the weather conditions, runway conditions, etc that airline pilots have to deal with in this country, having the nosewheel go off the end of a runway at 5 kts is really not a big deal.

[ReserveTank]

Just because the desination is technically dispatchable doesn't mean that you can land there. In an earlier post, someone stated that dispatch is predicated on dry/wet, which is correct. Snow/slush/wet ice is NOT taken into account for the dispatch requirement. It is incumbent on the crew to understand what is going on at the destination field. If there has been no field condition report and it is or has been snowing/sleeting/other, you need to know the clearing status. It needs to be in progress and making positive changes. You also should run numbers, if possible, for the expected conditions.

We ran into this issue preparing for a flight to a different airport, and we were getting the pressure to board and push. The conditions were similar, right down to the length of the suitable runway.

Field length: 7800'
Condition: SN/MEDIUM/3
Dispatch # for wet: 5250'
Calculated: With TR: 6900'/Without TR: 8900'

As you can see, perfectly dispatch-able, but we said no go, because the TR credit still puts us near the end. Any TR issue, and it's an overrun. Plow some more, we said. About 2 hours into a 4 hour delay, we received an ACARS saying that an A319 had just spun 180 while entering the rwy for backtracking, but stayed on the surface. Company dispatch to this airport was halted until a better surface condition report was released.

At the hotel, I talked to a captain of another airline that was supposed to go to YHZ. They declined to go due to lack of good info at the field, then of course, they heard about the Westjet overrun.

The point is this:

Don't allow dispatch to push you out unless you have a good idea of what's going on at the destination. As a general rule in the airline world, weekends are often staffed by the "B team," which means that things are going to happen slower and with a lesser degree of care, snow removal included. You need to be vigilant and understand that dispatch-ability by no means translates to ability to land. It's a tool to get the flight out under the premise that work will be done by the time your flight arrives. But if the work isn't happening then it makes no sense to depart, only to go to your performance alternate. Run the numbers!

[BGH]

Not related to the overrun but related to dispatch reliability from an airline captain friend of mine;
He was on his way out in a 737-200 & upon reviewing the dispatch info found that he was 8000 lbs light on fuel & requested the fuel be put on board before he would allow pushback - dispatch told him he was wrong & get going or he was going to lose his job.He told them that he was going to stand on the brakes & let them rip off the nosewheel because he didn’t have the fuel for the trip & it would be his ass;not theirs if he left without enough fuel for the trip.
Long story longer they relented to get the flight out but notified the head of flight operations that they wanted him made an example of for others.
Head of operations meets my buddy at the gate sometime really early in the morning & asks him how he’s feeling & then proceeds to tell him that if he didn’t have a really f’ng reason that he would be looking for a new job.He hands the guy the dispatch calculations & sees that there wasn’t enough fuel on board for the flight - dispatch hounded him at home for days to change his story to save the dispatchers jobs;he kept his job but checked every piece of info they ever gave him after that & found many errors such as an alternate that everyone else was using when heading to Europe in a 767,turns out it hadn’t reported any weather in almost a week.

Daryl

[GoinVertical]

Again, does anyone have 737-800 performance numbers handy?

Even using just the performance charts from the book it would be nice to have a ballpark number given the conditions to see how much wiggle room there was.

Does WestJet have the tablet on board that spits out performance data a la Encore?

[A346Dude]

Not related to the overrun but related to dispatch reliability from an airline captain friend of mine;
He was on his way out in a 737-200 & upon reviewing the dispatch info found that he was 8000 lbs light on fuel & requested the fuel be put on board before he would allow pushback - dispatch told him he was wrong & get going or he was going to lose his job.He told them that he was going to stand on the brakes & let them rip off the nosewheel because he didn’t have the fuel for the trip & it would be his ass;not theirs if he left without enough fuel for the trip.
Long story longer they relented to get the flight out but notified the head of flight operations that they wanted him made an example of for others.
Head of operations meets my buddy at the gate sometime really early in the morning & asks him how he’s feeling & then proceeds to tell him that if he didn’t have a really f’ng reason that he would be looking for a new job.He hands the guy the dispatch calculations & sees that there wasn’t enough fuel on board for the flight - dispatch hounded him at home for days to change his story to save the dispatchers jobs;he kept his job but checked every piece of info they ever gave him after that & found many errors such as an alternate that everyone else was using when heading to Europe in a 767,turns out it hadn’t reported any weather in almost a week.

Sounds like a shoddy operator that probably went out of business long ago. This story is not representative of the relationship between dispatch and crew of any reputable airline in Canada.

[indieadventurer]

WestJet doesn’t use tablet data for takeoff or landing calculations. They utilize AeroData through ACARS.

Regardless of whether it’s done through Boeing OPT on a tablet or through their method is irrelevant as both should provide the same numbers. Do keep in mind OPT will give you the 15% factored numbers, whereas AeroData, I think they do not include that factor.

Anyway, I ran it with good to medium braking and it was close with max auto brake around 7000 ft but had to make numerous assumptions.