More severe turbulence for Westjet


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It should be added that WestJet SOP requires one to allow for a larger margin than the published aircraft limitation or FMC calculated weight.

FAA certification allows one to operate to a 1.2 gust margin if I'm not mistaken. My personal limit is 1.35 and that's only if in smooth air. All it takes is an encounter with wake turbulence to shrink that margin substantially even for a small amount of time. Which could be just enough time to get upset.

Many forget that getting to max altitude (say at 1.2) wastes fuel getting there and wastes fuel staying there.

Why anyone would want to play with some of the bumpers west of Montreal is beyond me. They don't have to be monsters to be vicious.

I'll never forget sitting in the terminal in Slave Lake many Moon's ago (so to speak wink.gif ) ((would that have been a previous life? blink.gif ), watching the Cu pop above the Swan Hills. In less than 3 hours, Edmon-chuck centre was painting tops in the 50K+ range from that single solitary Cu.

Central Canada has monsters that go to 45K+, Alberta has 60K+. Where I'm flying now, you can routinely see 75K+ behemoths. At least one doesn't worry about tornados at the equator. And 150 mile diversions are the norm. These things will rip you apart without even shedding a lightning bolt.

Bottom line - most of us old farts learned the hard way years ago to avoid, Avoid, AVOID these things. Perhaps some of the younger generation haven't had the bejezus scared out of them enough yet.

Just some thoughts. I don't know what happened but anything approaching an upset scares the crap out of me - I've personally watched the approach of two but recognized the symptoms enough to not let it happen. That's twice too many times for me.

I wonder what the answer is... icon_question.gif

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Arctic Ace re The statement

"no margin for error at FL410" is quite misleading as we will not climb to FL410 or any other altitude until our weight and the atmospheric conditions allow us an "adequate margin for error". So we don't fly at FL410 until we have the same margin that we would require prior to climbing to any other high altitude. This is our policy at WestJet. The 737NG is quite comfortable at FL410 so we don't know that this crew had "no margin for error" at FL410"

If the two mentioned were unable to maintain altitude at 410 because they were overflying a thunderstorm (atmospheric conditions as you put it above) then I guess the margin of error wasn't enough, was it?

Why not just say, that "they were off the reservation and operating outside of WJ policy."

We all have policy for CB avoidance, its required by Transport to be in the operator's COM, its covered in line indoc and ground training too. As for our max operating altitude, it's more conservative then the aircraft's own FOM and accounted for in flight planing step climbs. Extra fuel is required and always given for diversions.... there is never a reason to go over top of any cell at WestJet.

Off the reservation? Outside of WJ policy? I can't find anything more about it except for an anonymous thread on the AEF. No one here really knows what happened... so its all 'what if' rumor mongering.

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Off the reservation? Outside of of WJ policy? I can't find anything more about it except for an anonymous thread on the AEF. No one here really knows what happened... so its all 'what if' rumor mongering.

Based on the credibilityof the initial posters I would say that it is not rumour mongering but probably based on fact. I can understand the need for WJ personnel to "circle the wagons"...nobody likes sand kicked in the face of one of their peers but stuff like this happens in every airline...someone does something outside of what most consider the realm of professional piloting.

Perhaps the crew members do not frequent the forum, perhaps they are on "days off"....it really doesn't matter ....the discussion concerning the event with all the additional...we do this ...I do that... it is recommended etc. ...is good for "learning".

One has to admit that there has probably been some valuable knowledge imparted in this thread.....and really.......it does not cast dispersions on WJ......perhaps just a crew not well versed in weather avoidance. Let's face it...if one is lucky one can fly for years and never encounter any untoward weather. wink.gif

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.... If the two mentioned were unable to maintain altitude at 410 because they were overflying a thunderstorm (atmospheric conditions as you put it above) then I guess the margin of error wasn't enough, was it? ....

That may be true, AC', but you're ignoring 'Ace's central point, that the coffin corner, margin for error, whatever we call it, can be perfectly acceptable up high, and tight at much lower cruising altitudes as well, relative to gross weight in cruise. e.g., A 100Klb 727 (the A/C that I fly wink.gif) has quite adequate maneuvre margins at FL410 (tho' not over top of CB's biggrin.gif), a 190Klb 727 at FL330 will not.

Re: the thread in general, Kip is right, these discussions can remind us of the verities of what we do, but in allowance to the more defensive WJ-ers, the early posts did seem to have a whiff of trolling/bashing to them. If Seeker's 1st post had had the same flavour as his 6th one, and not been followed by all the cone & chorus chatter, we might have got down to Kip's type of discussion a lot sooner IMHO.

For my own $0.02 - If the controller's response to the alleged WJ turbulence report was basically to gloat, 'I told you so', one penny for the guy that kicks him in the nuts. The other penny for the pilot who has never, ever seen a radar picture that seemed at odds with what others were doing. Stick around long enough, and most of us will eventually get a bumpy surprise. Keeping it in perspective, there doesn't seem to be any consequence or repercussion here.

Incidentally, if it was as described, this sounds like a reportable aviation incident (technically anyway). I can't get to the CADOR's on TC's website. Just for interest's sake, to anybody with access, was a report filed, if so, does it tally with the discussion here?

Cheers IFG beer_mug.gif

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