So WestJet almost puts one of their 737 in the water while landing at St-Maarten...

[Jet Jockey A4]

WestJet is trying to deny the aircraft ever came close to the water. Well I don't believe them and I will take this photographers word on this. Hope Transport Canada investigates this one.

http://i17.photobucket.com/albums/b79/mlab601/WestJet_zpstcjz6lls.jpg


More on this story here...

WestJet Denies Close Call Caught on Camera at St. Maarten (http://christinenegroni.com/westjet-denies-close-call-caught-camera-st-maarten/)

[Council Van]

referenced recent landing disasters, the 2013 crash of a Lion Air 737 in Bali, Indonesia in which investigators say the plane was below the minimum descent altitude when it hit the water half mile short of the runway. No one was killed. Obviously!

[ATCO1962]

If this is a real photo, how do you explain where the disturbance on the surface of the water starts with respect to where the thrust is coming out of the engines? Sure looks like Photoshop in action.

[fox niner]

Maybe it is the downwash from the wing and flap profile. If true and not photoshopped.

[Airbubba]

Well, the photos are unconvincing to me. Maybe the larger versions of the files have more detail. I find it odd that the picture of the second approach doesn't seem to have any of the shoreline elements of the first picture. Is the yellow buoy the same or is it another one further from the runway? There are several buoys in that area as I recall. Were both pictures taken from the same vantage point? That doesn't look like a 'jet blast trail in the water' to me in this compressed online image. But then, I've never flown a 737. :)

“According to the information I have been given there was nothing unusual about the first approach,” said Lauren Stewart, a spokeswoman for the Calgary-based carrier. Citing FlightAware logs, Stewart said the plane was never lower than 500 feet before the go-around. But professional pilots confirm Garner’s observation that the plane was much closer to the water and I have been told that FlightAware does not have coverage to the ground at SXM.

Maybe FlightAware doesn't cover down to the runway at SXM but FR24 does:

https://www.flightradar24.com/data/flights/ws2652#caa236c

Looks like they were holding for something, weather over the field perhaps?

[Jet Jockey A4]

The aircraft's nose is pretty high, so perhaps the power had already been added and they were just starting their missed approach.

Why would a pro photographer lie about her pictures? She is apparently known in the aviation world for her pictures.

One thing is for sure depending on the type of approach they were conducting (either a plain VOR 09 or VOR/DME 09) the MDA is abut 600' AGL or 960' AGL and the MAP is about at 2 nm from the runway threshold so if this picture is legit then they are way below MDA and way too far out.

One of the passengers said they came out of a rain shower and were very, very low, close to the water when the power came on and an aggressive pull up maneuver was initiated.

[DaveReidUK]

The second approach 45 minutes later came in much higher and for the passengers and crew of WestJet Flight 2652, the flight had a happy ending.

The FR24 data shows no discernable difference between the profiles for the first and second approach.

[Skyjob]

Nice find...
Looks low long enough to make image real
Look closely a the duration at end of flight when descending after holding, prolonged flight at approach speed at low level

[Airbubba]

Why would a pro photographer lie about her pictures? She is apparently known in the aviation world for her pictures.


What evidence do you have that she's a pro photographer? Can you find any of her work published professionally by anyone other than her buddy Christine Negroni?

Not saying that her work isn't nice, but as Christine Negroni describes her:

Yep, we’ve come a long way and so has global aviation. Christine Garner, a plane spotter/aviation enthusiast (is that redundant?) living in St. Maarten was reminded of that recently. She was having a normal afternoon at Maho Beach right off the west end of runway 10 at Princess Juliana International Airport, when a four engine airliner appeared in the distance. Not anticipating either the KLM Boeing 747 that arrives three times a week or the Air France A340, she picked up her camera and started snapping as it approached.

Airplane Images that Inspire Flights of Fancy (http://christinenegroni.com/airplane-images-inspire-flights-fancy/)

The FR24 data shows no discernable difference between the profiles for the first and second approach.

Surely you're not trying to ruin a good airline hit piece with actual data. ;)

[DaveReidUK]

Look closely a the duration at end of flight when descending after holding, prolonged flight at approach speed at low level

Really?

The final 3000' of descent was made at an angle of 3.15°.

[Metro man]

It wouldn't be difficult to pull up the flight data monitoring system and find out what really happened.

[NutLoose]

The trouble with telephoto lenses is they compress distance making objects appear closer to each other than they actually are.

[_Phoenix]

Two observations regarding the photo differences between first and second approaches. The aircraft position relatively to horizon and the differences in horizon visibility. It's pretty clear to me that 45 minutes between the go around and the second attempt was for "what the hell just happened" debriefing and for a better VFR approach, with 0 margin of error.

[Airbubba]

One of the things that makes me a little skeptical is the lousy image quality of the photo in the first post on this thread. It looks like something taken with a cellphone that my teen niece would post on Facebook. Not that there's anything wrong with that, but it doesn't look like the work of a professional photographer to me.

However, Christine Negroni responds to a claim of image manipulation with the information that she did a Picasa edit on the photos to make a montage for publication on her blog. From the comment section of the WestJet post:

Anthony says:

March 10, 2017 at 4:07 pm

It’s photoshopped. As a Graphic Designer, I have taken the opportunity to test the “Missed Approach” image in comparison to the “Good Approach” image and found many inconsistencies and artifacts which comes from a manipulated image.

Reply

Christine Negroni says:

March 10, 2017 at 4:53 pm

Anthony, Christine Garner is a professional aviation photographer with whom I have worked in the past for the prestigious Air & Space magazine. She is a woman of integrity and both of us take our professional responsibilities seriously. The image presented in the post is the image she shot and is NOT photoshopped. The final image with the caption, missed approach and good approach is a montage produced by me from her original images in the Picasa photo program. If there are “inconsistencies and artifacts” or something that suggests manipulation it must be related to putting two photos in one composite image. Christine Negroni

I've certainly had the experience of posting an online album of sharp edited photos of a family event only to have someone mix them with blurry, grainy cellphone pictures and have them downsampled to 20K thumbnails by Instagram and then resized back to original size with hideous results. :uhoh:

Again, about the only other published photography from Christine Garner that I can find online is in this article:

Under the Big Jets | Flight Today | Air & Space Magazine (http://www.airspacemag.com/flight-today/under-big-jets-180960365/)

From Christine G.'s online albums, it looks to me like she probably edits in Lightroom but I haven't found anything to confirm this.

Her son vouches for her integrity:

Bill Garner says:

March 10, 2017 at 5:47 pm

If you knew my mother (the photographer) you’d know that the image has not been photoshopped. It just isn’t in her character to fabricate something like this. Has anyone considered that they may have hit an air pocket and dropped suddenly?

There is a comment from another poster who says he also witnessed the event:

Trevor says:

March 10, 2017 at 4:44 pm

Allow me to address some of you experts – this photo was not photoshopped – I was in St Maarten and also witnessed the whole incident. I have been coming here annually for 16 years to photograph the aircraft and have never witnessed an aircraft so low. Rather than blame the pilots I prefer to give them a “great save”. The reason it took 45 minutes for the go around was that ATC closed the airport after the first Westjet approach. I was listening on my scanner

It does look like the airport was indeed closed for a while, INC 522 (Dominican Wings) and KLM 729 went into holding as well. KLM landed just before WJA 2652 and INC apparently diverted somewhere else.

[FlightlessParrot]

@Airbubba
Were both pictures taken from the same vantage point?

I should think clearly not. The first photograph was taken from a high angle, looking down on the sea, so the horizon is towards the top of the picture. The second photograph seems to be taken from a significantly lower angle. Of course, level of horizon is controlled by camera angle, but if you tilt the camera from a low angle, you get a lot of foreground.

I couldn't begin to work out the aircraft height in these two photographs, but they're certainly not directly comparable.

[Capn Bloggs]

The FR24 data shows no discernable difference between the profiles for the first and second approach.
First approach 1200fpm at 300ft, bottoming out at 0ft, second approach "almost normal"... no discernible difference there, obviously...

The final 3000' of descent was made at an angle of 3.15°.
If you're implying that it was an all smooth and dandy 3.15° approach, FR24 tells a completely different story.

Rider: I'm not implying anything about the accuracy of FR24, merely pointing out what appears to me to be poor/misleading interpretation of the FR24 info.

[B2N2]

I've been there several times in the last month.

Approach plates are here:

http://www.eddk.info/Download/PDF/TNCM.pdf

SID's and STAR's are here:

https://yinlei.org/x-plane10/jep/TNCM.pdf

Lowest MDA with DME is 500

http://i68.photobucket.com/albums/i3/PAA302/VORZRWY10.png

[Capn Bloggs]

Thanks B2N2. Interesting.

When are the approach designers of the world going to pull their fingers out and put Altitude/Distance profiles on their charts?!

[B2N2]

3 degree descent angle equals 700fpm at 140kts.
Possibly had it in VS mode with the Missed Approach altitude set after passing the FAF.
That's how we did it as the company I worked for was not approved for VNAV use in their Opspecs.

[Airbubba]

I've been there several times in the last month.

Approach plates are here:

Those approach plates might not be the ones WestJet was using, they are from 2003. :eek: Then again, maybe they were. ;)

[stilton]

Real or not it's just a matter of time before there's an accident here, the number of
approaches significantly below a normal glidepath in order for a few idiots to 'show off'
makes it inevitable.

[DaveReidUK]

If you're implying that it was an all smooth and dandy 3.15° approach, FR24 tells a completely different story.

No, it doesn't

(apologies, mods, for the size of the image, which shows each of the two approaches, from roughly 2500' Mode C at the extreme left)

http://www.avgen.com/WS2652.jpg

If there's more than 50-75' difference in the heights at any given point along the respective approaches, then that's not supported by the data.

Rider: I'm not implying anything about the accuracy of FR24, merely pointing out what appears to me to be poor/misleading interpretation of the FR24 info.Yours is the poor/misleading interpretation - neither you nor I can deduce absolute heights AMSL from the data without knowing whether or not it has been corrected for QNH.

All you can do with the data is compare the values for the two approaches (see above).

[compressor stall]

I'd be very careful trying to infer any height from a picture.

Many years ago I took some air to air shots of our aircraft. With the telephoto lens foreshortening perspective and the light it looked like the aircraft was skimming the surface. we actually thought twice about publishing the image to avoid awkward regulators questions.

[Capn Bloggs]

No, it doesn't
Yes it does. Drag the aeroplane symbol along and you'll see that that approach was nothing like 3.15° from 3000ft as you stated in your earlier post with the implication there was nothing wrong with it. It is clear that the first approach was above and then ducked down below the path of the second approach. Perhaps you are not a pilot. Gyrations in sink rate including 1200fpm at 300ft is not normal. If you discredit that info, then your claim of 3.15° from 3000ft is also discredited.

As for
Yours is the poor/misleading interpretation
That's why I stated "Rider...". :cool:

[TWT]

pilotmike
Have another look at the article.There is a second picture of the same 737 aircraft with a caption which says the picture is of the second approach.It's the 3rd picture from the top.

[DIBO]

Yellow line (rh pic) crosses extended centerline at 0.33 nm, both yellow lines follow the line of sight of the telelens.
I'm pretty sure about that, based on 2 landmarks that match both on telelens & on sat picture.
I guess the picture was taken from the Sonesta Maho Beach resort, from around 8-10th floor.
I leave it to the brighter spirits to draw any conclusions (or not if they are really bright).

[DaveReidUK]

Drag the aeroplane symbol along and you'll see that that approach was nothing like 3.15° from 3000ft as you stated in your earlier post

Here, for the geometrically-challenged, is the FR24 data plotted relative to a nominal 3.15° approach.

http://www.avgen.com/WS2652(2).jpg

The blue diamonds represent the first approach and the magenta squares the second one. Clearly an unquantified offset (based on the unknown QNH) needs to be applied to the two sets of data, otherwise both aircraft are in the sea short of the runway.

Yes, the first approach was lower than the second one by around 150' at about a mile from the threshold (so I stand corrected on my earlier 50-75' estimate), but the claim that the first approach was "nothing like 3.15° from 3000ft" is nonsense.

[Capn Bloggs]

Yes, the first approach was lower than the second one by around 150' at about a mile from the threshold

but the claim that the first approach was "nothing like 3.15°" is nonsense.
Are you even aware of the significance of a difference of 150ft at 1nm final??

[DaveReidUK]

Are you even aware of the significance of a difference of 150ft at 1nm final??

Yes, the words "too low" spring to mind. What's your point ?

[DIBO]

Elaborating at bit further on DaveReidUK's hard work (without the author's permission :O)

[Climb360]

https://m.youtube.com/watch?v=yNhAYKM-7LQ&feature=youtu.be

I guess at SXM there's always more than one camera 👍🏻

[Jet Jockey A4]

@ Climb360...

Well that takes care of that... So much for those that accused the photographer of manipulating her picture...

Yes I'd say that was a close call!

[wheels_down]

Speechless.

Someone's in trouble.

[DaveReidUK]

That YouTube video helpfully includes the TCNM METAR at the end.

A QNH of 1019 would indicate that actual heights AMSL will have been approximately 150' greater than the Mode C values.

[KelvinD]

Hmmm. The YouTube video shows, toward the end, a couple of stills and offers them as "proof" that the sky was about to fall in etc. The snag with this is the aircraft was further out when showing the second approach. Just look at the comparative sizes of the aircraft in the 2 stills. The second shot (missed approach) was taken when the aircraft was closer to the camera.

[Jet Jockey A4]

To me it looks like he is within a half wing span (~ 113') from the water, so about 60 feet?

[B2N2]

Those approach plates might not be the ones WestJet was using, they are from 2003

Those were the first decent Google search results.
In any case, good enough to prove a point.
Why people insist on using unverified data from a flighttracking website and present it as the gospel is beyond me.

[Sidestick_n_Rudder]

Perhaps there was some windshear involved? Othewise it's quite hard to explain why the plane descended so low while supposedly being visual with the RWY. But then again, so was the Asiana 777 in SFO...

[Hotel Tango]

OK, so they were a tad low (for reasons unknown to us). They did the right thing and went around for another go. They were never close to crashing. Just a lot of hype by people looking for a story to pep up a boring day. I have spent time watching approaches at SXM and seen Cessna C208 Caravans of FDX just as low....and continue to land.

[Jet Jockey A4]

@ Hotel Tango...

Won't argue with you about the missed approach part, they did the right thing but they were more than "a tad low" IMHO... The question we are asking is why?

There is nothing wrong in trying to find out why they got in that position where the aircraft was in an unstable condition at such a low altitude and I hope TC gets involved to get to the bottom of this.

[aterpster]

Bloggs:

When are the approach designers of the world going to pull their fingers out and put Altitude/Distance profiles on their charts?!

It's up to the country. If they publish such info on the AIP source, then Jeppesen will chart it.

[aterpster]

Hotel Tango:

OK, so they were a tad low (for reasons unknown to us). They did the right thing and went around for another go. They were never close to crashing. Just a lot of hype by people looking for a story to pep up a boring day. I have spent time watching approaches at SXM and seen Cessna C208 Caravans of FDX just as low....and continue to land.

In the U.S., it would be a violation of FAR 91.175 (c)(1):

(c)Operation below DA/ DH or MDA. Except as provided in paragraph (l) of this section, where a DA/DH or MDA is applicable, no pilot may operate an aircraft, except a military aircraft of the United States, below the authorized MDA or continue an approach below the authorized DA/DH unless -

(1) The aircraft is continuously in a position from which a descent to a landing on the intended runway can be made at a normal rate of descent using normal maneuvers, and for operations conducted under part 121 or part 135 unless that descent rate will allow touchdown to occur within the touchdown zone of the runway of intended landing;

[aterpster]

Air Bubba:

Those approach plates might not be the ones WestJet was using, they are from 2003.

The chart preceding your post was effective July 2, 2009. In any case it's not current. The VOR IAP was recently revised and a GNSS approach was added last month. I'll post them when I get a chance.

[B2N2]

In the U.S., it would be a violation of FAR 91.175 (c)(1):

No they're not if they were cleared for the visual approach which is not charted hence an MDA or DH would not be applicable.

[TBSC]

Maho webcam view (video)


https://www.youtube.com/watch?feature=youtu.be&v=0uPTdKwWo78&app=desktop

[B2N2]

Did they go-around because the truck didn't appear to be stopping?

[Jet Jockey A4]

Well I hope not... They were way too low and I think they were already in the "Go Around" mode regardless of the truck approaching from the south.

[aterpster]

B2N2:

No they're not if they were cleared for the visual approach which is not charted hence an MDA or DH would not be applicable.

A visual in that weather? In that case, in the U.S., they would be required to use the VGSI, which is 3 degrees for Runway 10.

In any case, here are the two current approach charts.

[Airbubba]

Why people insist on using unverified data from a flighttracking website and present it as the gospel is beyond me.

Yep, that newfangled ADS-B stuff will never be accepted by polite society. ;)

It appears that the data was pretty good in this case. :ok:

In any case, here are the two current approach charts.

If they did the published miss, looks like they took the 180 degree track on the VOR-Z Rwy 10 rather than direct ONBED on the RNAV (GNSS) Rwy 10 approach, according to unverified data from a flight tracking website :).

It does look like the airport was indeed closed for a while, INC 522 (Dominican Wings) and KLM 729 went into holding as well. KLM landed just before WJA 2652 and INC apparently diverted somewhere else.

Trevor from the comment section in Christine N.'s blog adds this:

Trevor says:

March 11, 2017 at 6:42 am

Let me clear up a few things – I was in SXM listening to ATC all afternoon. American Flight 2219, a Boeing 737 from Miami had just landed before Westjet and reported to the Tower that they only picked up the field at the last minute (I presume that meant before they decided to go around). The Westjet approach was next and lets be clear, ATC did not advise them to go around, it was the pilots decision. ATC did comment that the decision to go around was very late – Westjet did not respond – ATC advised them to climb to 4000 feet and hold at Ivaci – the airport was then closed to arrivals and departures. About 20 minutes into the hold, Westjet was informed that the visibility on approach had improved from 11/2 miles to 2 miles and asked if he wanted the approach. He declined, indicated he had plenty of fuel to hold and would wait for further improvement. KLM Flight 729 then arrived, an Airbus A330 and was told to enter the hold. He indicated he did not have sufficient fuel to hold and wanted to try the approach – ATC complied with his wish and he landed safely – he reported that he picked up the field at 3 miles. Westjet then decided to make the second approach and it was flawless. As an aside, Insel Air was also in the hold, a Dominican Wings A320, and he decided to divert to Guadeloupe

[aterpster]

Airbubba:

If they did the published miss, looks like they took the 180 degree track on the VOR-Z Rwy 10 rather than direct ONBED on the RNAV (GNSS) Rwy 10 approach, according to unverified data from a flight tracking website.

Perhaps they elected the VOR Z because of the 200-foot lower MDA. (Confusing, ain't it?)

WestJets is an RNP AR intensive carrier, and perhaps usually does other vertically-guided IAPs when they aren't approaching one of their RNP AR airports.

Perhaps, a first glance at the charts when the weather is "going south" in paradise would be to go for the VOR Z.

[pattern_is_full]

Takeaways:

- make sure to apply skepticism to your own thinking, and other skeptics.

- expect pilots to know as much about Photoshop as photographers know about flying.

;)

[helimutt]

I'm more concerned with "KLM Flight 729 then arrived, an Airbus A330 and was told to enter the hold. He indicated he did not have sufficient fuel to hold and wanted to try the approach"

[Noxegon]

At a guess he may not have had enough left to hold over SXM and later divert to his alternate with contingency?

[andrasz]

Video of both approaches taken from the beach, posted on YT yesterday:
https://www.youtube.com/watch?v=yNhAYKM-7LQ

Confirms that the originally posted photo was not doctored, they were indeed a tad too low for comfort...

[noflynomore]

On a slightly different note I hope to God this isn't going to start a habit of beginning threads with the word "So" like the meaningless, idiotic habit that's been infesting spoken language recently.

[aterpster]

With those videos my hunch is the Canadian aviation authorities will get involved.

[the_stranger]

I'm more concerned with "KLM Flight 729 then arrived, an Airbus A330 and was told to enter the hold. He indicated he did not have sufficient fuel to hold and wanted to try the approach"Why?

All it says is that they arrived with not enough fuel to hold and divert and have 30 minutes remaining. Nothing wrong with that, it just makes you take a decision earlier on.
IF he went around, or still had to enter the hold, he would have to divert immediately.

[cappt]

The pictures are deceiving. They were no longer in a position to land "normally" so they executed a go around.
A plane spotters wet dream.

[FullWings]

Having watched the video of the two approaches viewed from the same point, the first one does appear to be seriously low, four reds on the PAPI (if they can even see it). The airport video doesn’t look so pretty, either.

One does wonder what the view out of the front window was like for the last 30s or so... :eek:

[andrasz]

The pictures are deceiving


Thie pictures may be, but the videos taken from the beach (= threshold elevation) show a very clear picture. From the shadow under the aircraft one may have a fairly accurate height estimate on the first approach, they were at an altitude less than a full wingspan when the go-around was commenced, about 75-80 feet. On the second approach they were roughly at two wingspans (~200 feet), about right for 0.5nm before threshold.

[aterpster]

Folks can say what they want about the photos and videos, but the DFDR doesn't lie.

[skidbuggy]

https://www.youtube.com/watch?v=yNhAYKM-7LQ

Judge for yourself

[Airbubba]

Christine Negroni got her WestJet SXM article picked up by Forbes' website with a different edit of the first low approach photo and a book plug at the end:

https://www.forbes.com/sites/christinenegroni/2017/03/12/airport-known-for-thrills-comes-uncomfortably-close-to-drama/#6a14d8c75492

The EXIF data says that the picture was taken with a Canon EOS 6D camera, a lot of folks would call this a 'prosumer' model.

And the EXIF data says the photo was edited in, gulp, Photoshop 6. :eek:

Actually this in itself is nothing sinister, Christine Garner probably used Photoshop mainly to apply the eponymous watermark.

[16024]

I don't fly into TNCM so shoot me down if I am out of line.
But it's not a short runway (2300ish) for a medium jet.
I imagine the visual manoeuvre on departure would make an engine out climb more than usually emotional, but why is there such approach carnage? Or has it just been blown out of proportion by the utubers.

[Captain Capstan]

2300 metres is plenty long enough for a 737. We regularly operated from 1600 metres.

[costalpilot]

not sure what runway length has to do with being that low on final?

[breakdip]

That's about our standard operating height... :8

First attempt, whether they were too high or too low, proper response of the crew, right? Second attempt, no signs of sweat.

With the knowledge they have now, will they wait out the weather in the future? Raise their own minima?
Not knowing whether windshear is involved here, are there companies that have specific SOPs when windshear can be expected? (e.g. Higher approach speed, raising the minima).

[Hotel Tango]

The standard of the last 4 posts would seem to suggest it's time to close the thread now!

[Seabreeze]

If the photo is true, with the a/c appearing below the horizon, then the actual height of the a/c must be below the height from which the photo was taken, and that looks to be only a couple of hundred feet at most.

SB

[readywhenreaching]

We do not have any substantiated reason to believe the photo was falsified. It fits with both videos from Mahobeachcam and the Sunset Bar and corresponds to adsb tracking as well.
The altitude must be seriously lower than 100 ft leaving a trail of backwash behind.
JACDEC suggested a height of 15-20 meters at the moment when the photo was taken. LINK (http://www.jacdec.de/2017/03/12/2017-03-07-westjet-airlines-boeing-737-800-too-low-near-sint-maarten/)
http://www.jacdec.de/WP/wp-content/uploads/2017/03/2017-03-07_C-GWSV_B738_WJA@StMaarten_lowAppr_MAP1.png

[no sponsor]

Well, at least they went around off the low approach.

[The Dominican]

This particular airport in my opinion is an accident waiting to happen and it has nothing to do with the rwy nor the terrain at the end....., afterall, there are thousands of airports with those specs around the world and you don't see people going bellow their 3' VPA into the touchdown zone. 34R/16L in Narita is about the same and you see operations everyday with 777's on down without seeing these spectacles of trying to touch the top of the fence with the mains.

I believe that it has to do with the beach and the next youtube video showing your plane being within reach of the girls at the baech......., for show! That's all, there is simply no operational reason as to why the aming point seems to be the start of the displaced threshold markings.

[T28B]

OK, so they were a tad low (for reasons unknown to us). They did the right thing and went around for another go. They were never close to crashing.
Further up thread, someone (apparently a non aviator) suggested:
Rather than blame the pilots I prefer to give them a “great save”. I'd downgrade somewhat that to "wave off a bad approach is what we are supposed to do."

The point being made by some of the aviators in this discussion is the criticality of precision flying in close/stable approach, etc. With souls on board, it's a worthy standard to aspire to ... and "do the right thing" and wave off when one misses the mark.


If the witness named Trevor is to be believed:
American Flight 2219, a Boeing 737 from Miami had just landed before Westjet and reported to the Tower that they only picked up the field at the last minute (I presume that meant before they decided to go around). The Westjet approach was next and lets be clear, ATC did not advise them to go around, it was the pilots decision. ATC did comment that the decision to go around was very late – Westjet did not respond – ATC advised them to climb to 4000 feet and hold at Ivaci – the airport was then closed to arrivals and departures. About 20 minutes into the hold, Westjet was informed that the visibility on approach had improved from 11/2 miles to 2 miles and asked if he wanted the approach. He declined, indicated he had plenty of fuel to hold and would wait for further improvement. KLM Flight 729 then arrived, an Airbus A330 and was told to enter the hold. He indicated he did not have sufficient fuel to hold and wanted to try the approach – ATC complied with his wish and he landed safely – he reported that he picked up the field at 3 miles. Westjet then decided to make the second approach and it was flawless. I have a few thoughts on what may have happened on the initial approach, but for the moment will put them in a holding pattern, awaiting improved visibility. ;)

[RAT 5]

First attempt, whether they were too high or too low, proper response of the crew, right? Second attempt, no signs of sweat.

This being a Professional Pilots forum I'm interested in what they did differently such that there was a different outcome. How had they made the 1st approach; VNAV or V/S? Why are there no Alt/DME checks below 1600'? (shown on the offered charts post #17). Was the 1st approach a 'dive & drive' and they went below MDA? Was the 2nd approach a CDA? What is Westjet's SOP for such a profile?

I am curious about the chart profile. 3 degrees = 320'/nm. You start at 4.8nm from THR.
Charted FPL is 2.98 and is reflected in the G/S at 140kts being just <750fpm. So that jives. It then shows the 'M' at 1.9nm from THR and a MDA or 486' AGL starting from a TOD 1586' at 4.8nm.

Using 3 degrees (a little steeper) you would be 1536' AGL at 4.8nm. The chart is 1586'? At 1.9nm on a CDA 3 degrees you'd like to be 608' AGL; the chart shows 'M' as 486'AGL. Thus on a CDA 3 degrees you'd hit 486' AGL after the 'M' at 1.5nm to THR. Indeed, the 2.98 dotted line appears to cross below the MDA level at 'M'.
So is this a dive & drive NPA? Descend at 1000fpm to 500QNH and level until flying into PAPI's?
The required VIS 3500m, is just enough to give threshold in sight at 1.9nm which coincides with 'M'. There are no approach lights, so 'the beach' is not good enough.
I would suspect an A330 flies a CDA. I've never been there, but is the GA flown passing 2nm DME or at 500' QNH. My point being that on a CDA 500' QNH is not at 2DME, but later. At 2nm DME you'll still be above MDA. On a Dive & Drive the GA will be 2nm from level flight.

[Hotel Tango]

The Dominican: I'll remain polite and simply say that I totally disagree with you! In respect of this particular occurrence (I don't even want to describe it as an "incident") I think the last thing on the crews' minds in the prevailing wx conditions was any desire to try and impress the few braving it on the beach. I again emphasize that no one here is aware of the facts. They found themselves a little too low and executed a G/A. To suggest that professional airline crews would engage in deliberately low approaches in the interest of making the YT videos Top Ten is, in my opinion, not worthy of serious consideration.

[NutLoose]

Christine Negroni got her WestJet SXM article picked up by Forbes' website with a different edit of the first low approach photo and a book plug at the end:

https://www.forbes.com/sites/christi.../#6a14d8c75492 (https://www.forbes.com/sites/christinenegroni/2017/03/12/airport-known-for-thrills-comes-uncomfortably-close-to-drama/#6a14d8c75492)

The EXIF data says that the picture was taken with a Canon EOS 6D camera, a lot of folks would call this a 'prosumer' model.

And the EXIF data says the photo was edited in, gulp, Photoshop 6. http://cdn.pprune.org/images/smilies/eek.gif

Actually this in itself is nothing sinister, Christine Garner probably used Photoshop mainly to apply the eponymous watermark.

The camera will put copyright info with the image, the 6D is the smallest lightest full frame camera and the lines between "prosumer"are blurred these days, it is horses for courses and you vary the models you use to what you want to get out of it functions wise, the important thing is simply the glass, no matter what your camera is or does, shooting through third rate glass always will result in a third rate image.
Photoshop is used to tweak the image and crop etc, also to convert the image if shooting in RAW. Though six is an old version, then again back to the horses for courses and if it is doing the job, why change.

[Mr Magnetic]

The EXIF data says that the picture was taken with a Canon EOS 6D camera, a lot of folks would call this a 'prosumer' model.

You'll pay up to a grand and a half for a 6D body alone and the glass that is also shown in the EXIF data (EF70-200mm f/2.8L IS II USM) will easily set you back another grand and a half, so that's £3000 worth of "pro-sumer" gear right there without counting any of the other bits and pieces she would have undoubtedly had with her...

[Airbubba]

The camera will put copyright info with the image.

The Canon 6D will put copyright info into the EXIF file but won't put it on the image with the fancy font.

the important thing is simply the glass, no matter what your camera is or does, shooting through third rate glass always will result in a third rate image.

The lens Christine Garner used is certainly pro quality.

My initial caution over accepting the original photos as unquestionable evidence of a near disaster came largely from the poor image quality of the pictures as first published by Christine Negroni. Also, the assertion that they were taken by a professional photographer well known in the aviation community didn't quite seem to pan out from a quick look around online.

Christine N. says the original pictures were re-edited in Picasa for her blog, that certainly explains the image quality issue to my satisfaction. And, even if you do a minimal edit with a great original file, sometimes the blog software will butcher the picture with compression and other artifacts when it is published online.

Christine G. does some great photography but, like me, I don't believe she earns a living as a professional photographer.

Anyway, the photo of the low approach posted in the Forbes online article appears to be a minimally edited jpeg. It is razor sharp, and I think she probably quickly zoomed out to get the shoreline elements for context when she saw what was happening.

[Airbubba]

34R/16L in Narita is about the same and you see operations everyday with 777's on down without seeing these spectacles of trying to touch the top of the fence with the mains.

Actually, the 'B' runway at NRT is now lengthened since the farmer has gone somewhere else. But it indeed used to be 7152 feet long with widebodies landing on it. Now, about those brake fans... ;)

[Viper 7]

Albeit in a medium helo; I have arrived at DH, had the runway environment visual, elected to land and then had the vis subsequently deteriorate in drifting fog. I realize I don't have to tell most folks here that there is no guarantee that the quality of what you can see at DH will continue to the threshold. Perhaps that is the case here.


I "grew up" in a flying community where the older pilots used bad weather and maintenance days to drink coffee and talk about tight spots they got into and out of thus allowing us sprogs to learn from their near-fatal mistakes. I suspect that their candour and professional courage prevented a lot of accidents, the number of which sadly cannot be quantified.


It would appear that we won't have the opportunity to learn from this incident in the same manner which is a pity, as most CFIT lessons are tempered by speculation and can't benefit from a first hand perspective from the cockpit.

[jaybmc]

Good decision for a go around. Low VI's on a non precision approach with both pilots looking for the runway, along with a lack of depth perception over the water with little horizon, it's a rather classic setup for such a mistake. Any of us who have spent time over water have fought this, especially in our young single pilot days. Same issues as black hole approaches. Makes me think of Kalitta at Gitmo.

[16024]

The standard of the last 4 posts would seem to suggest it's time to close the thread now!
Hotel Tango, well here is your chance to shine!
They found themselves a little too low and executed a G/A. To suggest that professional airline crews would engage in deliberately low approaches in the interest of making the YT videos Top Ten is, in my opinion, not worthy of serious consideration.
Quite.
So why does it keep happening? Still seems like a reasonable question.

[albatross]

I think we have flogged this one to death with a big stick.

[scifi]

There again, most pilots have been trained to fly at 50ft or lower, for hours on end..
.

[FullWings]

Good decision for a go around. Low VI's on a non precision approach with both pilots looking for the runway
You do that at MDA. If you can’t see it you go-around. If you lose sight of it later on, you go-around. What you don’t do is carry on lower and lower *hoping* to see something: many have died doing this, which is why we have minima.

It would be interesting to know what guidance the PF was following before they went around that got them in the position they ended up in...

[Hotel Tango]

16024 So why does it keep happening?

So, you're suggesting that "it keeps happening" at SXM do you? Enlighten us further by all means. Do you have any factual knowledge about this airport?

As for recorded accidents, there was an "arriving" accident at SXM in 1971 and that was a DC-3 which crashed 20 miles short due to fuel starvation. In 1972 an DHC-6 crashed on a night approach. In 2014 a Shorts 360 crashed on departure.

Looking at its safety record I would say it is no more an accident waiting to happen than hundreds of other airports around the world.

[Aluminium shuffler]

If the photo is real, then altimetry error would explain the low altitude and the ADSB reports of being on profile as the ADSB would report GPS 2d position and baro altitude. Given how many non precision approach accidents have been caused by misset altimeters, it seems a plausible explanation, especially if the local QNH was below standard.

[16024]

16024 posted:
I don't fly into TNCM
Hotel Tango replied:
Enlighten us further by all means. Do you have any factual knowledge about this airport?
Guys, is it just me?
I was just asking.
For perspective last 2 flights for me were NPA into coastal runways, and one of those requires a 45 degree turn after break-off to line up, and the other one has PAPIs that are known to be as good as useless. Neither airport makes it into the hysterical "scariest landings" posted all over the interweb.

[16024]

Ok, I tried.

[aterpster]

Alum shuffler:

If the photo is real, then altimetry error would explain the low altitude and the ADSB reports of being on profile as the ADSB would report GPS 2d position and baro altitude. Given how many non precision approach accidents have been caused by misset altimeters, it seems a plausible explanation, especially if the local QNH was below standard.

With all the publicity this incident has received, it's likely that the experts at Transport Canada will take a good look at the DFDR.

[FullWings]

If the photo is real, then altimetry error would explain the low altitude and the ADSB reports of being on profile as the ADSB would report GPS 2d position and baro altitude.
I thought the baro altitude is referenced to standard then the adjustment made for QNH elsewhere, like a transponder. Stand to be corrected...

[Herod]

I'm puzzled. Surely they had some indication of distance-to-run, even if they just set an extended centreline manually several miles from the threshold. Altimetry error should be discounted on this one, since a Rad Alt readout will give a good clue, It's a sea-level airfield

[DaveReidUK]

I thought the baro altitude is referenced to standard then the adjustment made for QNH elsewhere, like a transponder. Stand to be corrected...

Correct.

In this case, add approximately 150' to the Mode S/ADS-B altitudes to get true AMSL values.

[Airbubba]

Given how many non precision approach accidents have been caused by misset altimeters, it seems a plausible explanation, especially if the local QNH was below standard.

I share your suspicion about a misset altimeter but it appears that the QNH was 1019 hPa according to a weather sequence attached to one of the YouTube videos.

I would suspect an A330 flies a CDA. I've never been there, but is the GA flown passing 2nm DME or at 500' QNH. My point being that on a CDA 500' QNH is not at 2DME, but later. At 2nm DME you'll still be above MDA. On a Dive & Drive the GA will be 2nm from level flight.

From the approach plate it lists the MDA (H) (CONDITIONAL) as 500 feet. It's one of those 'find the faces in the picture' exercises they used to love in airline interviews but it looks to me like you can go to 500 feet if you can stay at 205 knots or below on the miss until you are on the 180 degree track. It's note 1 on the bottom, not to be confused with note 1 on the top of the plate about DME required.

If you can't stay at or below 205 knots in the turn, your MDA is 770 feet it appears to me. I'm guessing the B-738 on a straight in approach is Cat C for the right side mins table.

I agree that it seems that the 2.98 degree path puts you higher than 500 feet at the 2 DME fix. I get about 601 feet for the charted 1.9 nm to the threshold, plus 50 feet for the TCH and 14 feet elevation for about 665 feet at D2.0.

So, you would indeed go missed at the D2.0 [MA10] point on a CDA before reaching 500 feet. I haven't trained for or done a dive and drive non-precision approach for many years and I thought they were pretty much extinct in airliner ops by now.

But in the past, there were options to do a CDA on a path in VNAV, speed intervene (to avoid throttle surge on some Boeings), a CDA on a path with V/S or a dive to mins early, level off and then land or go missed at the MAP depending on what you saw. On the CDA's you would go missed at MDA without visual contact and not level off even if you hadn't reached the charted MAP.

Is it possible that the WestJet crew saw that they could go just a little lower with an early descent below path to 500 feet before D2.0 and lost track of the altitude before breaking out so low? Does the B-738 give an audio callout at minimums on path that they were expecting but may not have got due to the setup in the box? Obviously, altitude needs to be closely monitored whether the automatic callouts work or not.

[16024]

Does the B-738 give an audio callout at minimums on path that they were expecting
Depends on customer specification.

[FullWings]

Is it possible that the WestJet crew saw that they could go just a little lower with an early descent below path to 500 feet before D2.0 and lost track of the altitude before breaking out so low? Does the B-738 give an audio callout at minimums on path that they were expecting but may not have got due to the setup in the box? Obviously, altitude needs to be closely monitored whether the automatic callouts work or not.
I would really like to know how they got themselves to almost sea level short of the runway so I can avoid the trap they fell into next time I’m in that position.

Giving the benefit of the doubt and assuming that they didn’t just bust minima and get woken up by the 100R call, what could have led to this incident? Visual at MDA but going slightly under then a confusing picture? Following an inappropriately programmed flight director in a visual segment? There’s no extended approach lighting so you’ve got to be able to (continuously) see the runway and/or slope guidance in order to continue.

What was so convincing that it almost put them in the sea following it?

[ACMS]

Was there a Windshear event? Microburst event?

Wait for the FDR amd official report

[Aluminium shuffler]

Airbubba, misset alts is the most plausible explanation to cover the actual and ADSB profiles. My comment about lower than standard pressure would have made the error even easier to make, simply forgetting to select QNH at transition, but the error can still occur from a misheard or mal-transmitted QNH. Whatever the cause for altimeter error, it's still the leading cause for non-precision app accidents and fits well here as something to be investigated. It may, of course, have nothing to do with this event...

[Ian W]

Airbubba
I share your suspicion about a misset altimeter but it appears that the QNH was 1019 hPa according to a weather sequence attached to one of the YouTube videos.

That would put the aircraft 180ft lower than the 500ft MDH so 320ft. Is that enough error to show in that picture?

Note: The number of altimeter setting errors reported to ASRS is extremely high.

[RAT 5]

So, you would indeed go missed at the D2.0 [MA10] point on a CDA before reaching 500 feet.

Interesting. Because all CDA SOP's I've used are to GA at MDA if no contact. In Europe I've not come across this situation where 'M' is reached before MDA. From passed Ops 'M' was the decision point on a Dive & Drive. True about Cat C for B737/8. If you didn't use 500' MDA you would be in real trouble at 'M'. If the vis was only 3500m. i.e. coordinated with 500' & 1.9nm you would be very high if stopping at 770' and unstable to land.
The comment about the RA shouting at the crew about their true height is valid. I wonder if Westjet set MAA after leaving platform alt, or set 500' on MCP. If the latter the A/P or FD would level off. If MAA was set then the "+100" or "approaching minimums" & "minimums" would also shout at the crew. They would be looking out of the window. I wonder if much earlier they had been sucked into "sea contact" vertically, i.e. knowing there was nothing to hit except a ship's mast. Were they manual or A/P CMD?
Back to my earlier question: I would be interested to know what they did differently the 2nd time.
Regarding the 'photo shopping' of the first photo; why would she? Why take the 1st & 2nd photos, doctor the 1st, publish them with accusations and set of a manure storm that can easily be answered by the Canadian CAA. They have the crew and technicians to solve that problem should it be true. After all, they did make a GA.

[FullWings]

Was there a Windshear event? Microburst event?
Possibly, though you’d have thought they’d have said something afterwards and/or performed the WEM at the time...
Wait for the FDR and official report
Fair enough but we don’t know if it was reported.

[geewhizdriver]

Yesterday, here in YYC where West Jet is based, the local media aired the video of the infamous approach. West Jet finally acknowledged that the approach was in fact too low. They claimed that due to rapidly changing weather conditions on the approach, the crew defended below the glide path but quickly corrected and executed a missed approach as they are so thoroughly trained to do! Of course they downplayed the entire event, and suggested that the event will further enhance safety at WJ as the event will be reviewed and shared amongst crews. I'm assuming that this will be done through their SMS, but herein lies the disparity. Realizing that an airline has to maintain a positive public image, they chose to ignore the event or downplay its seriousness. The premise of an SMS is full disclosure. Come clean with what occurred, identify the weaknesses, develop changes to procedures so it won't re occur and share the process. ( at least that's how TC here in Canada wants the system to work). When the company denies the significance of an occurrence does it not promote a culture within to not embrace SMS. Here in Canada, that means back to fulll regulatory enforcement, and disciplinary action against the airline, crews and management.

[YRP]

It seems like a bigger deal is being made of this than needed. They were low, yes, but it seems like a matter of getting visual with the runway then either gusting winds/windshear or illusions / misjudgement due to the weather. But the key thing is that they realized their mistake, admitted it, and went around as they should have.

No one is free from making mistakes, the key is to recognize and react. Seems like they did that here.

About the descending below MDA, they likely did so and did so correctly: being visual with the runway and continuing as normal. We have a clear view of the aircraft in the photos and videos from various vantage points. While there was some weather and rain, the pilots must have been visual with the runway and lights.

[Dadanawa]

Some interesting points about the VOR approach into SXM.

If descending to an MDA of 770 feet the VDP distance is 2.2 DME.
If descending to an MDA of 500 feet the VDP distance is 1.5 DME.

So if WestJet was descending to 770 feet, the prevailing visiblity might not have enabled the runway to be visible.

Clearly though, the aircraft was below 770 feet on the go-around.

Probably descended below MDA, broke out below the 3 degree path, and executed a go-around.


http://i779.photobucket.com/albums/yy71/Dadanawa/IMG_1805_zpssq3fpqno.png (http://s779.photobucket.com/user/Dadanawa/media/IMG_1805_zpssq3fpqno.png.html)
http://i779.photobucket.com/albums/yy71/Dadanawa/IMG_1806_zpsxrbkngoq.png (http://s779.photobucket.com/user/Dadanawa/media/IMG_1806_zpsxrbkngoq.png.html)

[Airbubba]

Airbubba

That would put the aircraft 180ft lower than the 500ft MDH so 320ft. Is that enough error to show in that picture?

Note: The number of altimeter setting errors reported to ASRS is extremely high.

If they forgot to set the local altimeter and left things at 1013 hPa, wouldn't they actually be higher than the 500 feet indicated baro altitude?

Those low transition levels (FL 65 in this case) are spring loaded to mess up. I've sure made the mistake myself but had the luxury of catching it on an ILS crossing altitude.

Was there a Windshear event? Microburst event?

Wait for the FDR amd official report

There may never be an official report is my guess. Is there some official Canada government site that might list this as an incident to be investigated? Or, will the Dutch authorities possibly take a look?

So, you would indeed go missed at the D2.0 [MA10] point on a CDA before reaching 500 feet.

Interesting. Because all CDA SOP's I've used are to GA at MDA if no contact. In Europe I've not come across this situation where 'M' is reached before MDA.

I agree that it looks odd, am I perhaps misreading that chart? Also, somebody check my math(s) on the D2.0 crossing height for a 2.98 degree path. I figured 1.9 nm equals 11,545 feet multiplied by the tangent of 2.98 degrees gives 601 feet of altitude change plus 64 feet for the 50 foot TCH on the chart. In the past, non-precision approach calculations did not include the TCH in some cases and you had to manually add it to the FMS to get a good advisory descent path.

Also, on a non-precision approach, even if a nice path is depicted in the FMS, it doesn't guarantee that path will continue to the touchdown zone in my experience. Years ago the LOC Rwy 27 at SAN (San Diego, California for that feller who couldn't figure out how to Google 'prosumer' ;)) had a nice path in the box to the runway threshold but since the actual touchdown zone was displaced, you had to add power and level off momentarily to get on the PAPI's for the rest of the descent.

[DaveReidUK]

If they forgot to set the local altimeter and left things at 1013 hPa, wouldn't they actually be higher than the 500 feet indicated baro altitude?

The "baro altitude" that the OP is referring to is the data sent by the transponder (which is the only information we have access to at this time).

That data isn't affected by whether or not the crew set the correct QNH on the altimeter subscale.

[Airbubba]

The "baro altitude" that the OP is referring to is the data sent by the transponder (which is the only information we have access to at this time).

I believe Ian W. was talking about the misset altimeter scenario causing a faulty indication in the cockpit from the context of his quote of my earlier post.

See: http://www.pprune.org/9706787-post99.html

It's easy to get busy down low and miss the transition level, especially when it's below FL100 dodging weather in the Caribbean. And, with the accents, 1019 might certainly be heard as 1009.

A misset altimeter is definitely one of the things that can ruin your whole day on a non-precision approach down to minimums.

Another thing that can get you on the NP approach is a bad setup in the FMS giving you a path that is not the right one. Still, it shouldn't get you below minimums without the runway in sight if you do the call outs and adhere to stable approach criteria.

Christine Negroni has a picture of the UPS BHM A300 crash in her article linked on the first post on this thread. In that mishap, the crew had an incorrect FMC setup with a bogus path that was above them. For some reason, the captain V/S'ed them into the ground with 1500 feet per minute down at 1000 AGL, which should have been an automatic go around.

[er340790]

the crew defended below the glide path

Descended?

Shurely shome mishtake...

[RAT 5]

What I find odd is that there are no DME/ALT checks after 1600' at 4.8nm. EFIS a/c do LNAV/VNAV descents to MDA. (the chart shown in #17 is not an RNAV approach. Is there one?) However, older, perhaps more private a/c are steam driven. This would invite, especially over the obstacle free sea, a Dive & Drive profile. Either way, the crew procedures should be a level off at 500' or 770' until 2nm and a decision if the runway is in sight yes/no. Then a land or GA decision.

I have to admit, if was in my (dream on) private twin prop on a murky day with a hot date waiting, I might be tempted to shave a bit off (if you get my drift) and nibble below the belt to see if I could get in. However, I would not like a crowd to join me, so I think in a B738 case I'd be respecting my master and his rules.

[Aluminium shuffler]

Rat, the "M" is the missed app point. It's not a great name for it. It's not the point at which you should commence a missed app; that should happen at the minima on the glide path. It is the earliest point that lateral navigation should switch from the approach path to the missed app path, preventing early turns on intercept headings and not relevant (and hence rarely shown) where the missed app tracks a radial or is flown straight ahead.

The minimums callout, automatic or from PNF, would, on a non-precision app or Cat 1 ILS be baro alt related, so again, incorrectly high subscale settings would create an excessively low callout. More evidence that this could be the cause, but, again, far from conclusive.

The 737NG does not have GPS related altimetry, though the side profile view on the NAV display on aircraft with this customer option will show a GPS derived profile to a database display of terrain and airfield elevation. While there is no warning generated, a close look at that profile wile show a mismatch between baro and GPS profile by having the runway floating above or buried under the terrain, depending on which direction the altimeter setting error occurs. The rad alt displays from 2500' on the PFD. Custome spec may have a number of automatic callouts. Any crosscheck against the baro alt while over the sea should have revealed misset altimeters if that was the case.

[DaveReidUK]

I believe Ian W. was talking about the misset altimeter scenario causing a faulty indication in the cockpit from the context of his quote of my earlier post.

You may be right.

It's probably worth clarifying what we can deduce (based on the transponder data) to have been the minimum height to which the aircraft descended on its first approach (at approximately 1.1 nm from the threshold):

Baro height: 100' (to nearest 25')
Actual height AMSL: 250' (approx - based on baro height, adjusted for METAR QNH)
Altimeter indicated height: we don't know (but likely to have been close to one of the two above values unless a completely spurious subscale setting was used)

[Airbubba]

What I find odd is that there are no DME/ALT checks after 1600' at 4.8nm. EFIS a/c do LNAV/VNAV descents to MDA. (the chart shown in #17 is not an RNAV approach. Is there one?)

There is a new RNAV (GNSS) Rwy 10 posted earlier:

http://www.pprune.org/9702902-post48.html

What makes me think that WestJet shot the VOR Z is that the missed approach on the WS 2562 ADS-B track looks more like the 180 degree course of the published miss on the VOR approach rather than the direct ONBED missed approach on the RNAV plate. Also, with weather at minimums, MDA is 500 feet on the VOR approach, 700 feet for the RNAV.

Of course, the tower may have given them turn right heading 180, maintain 4000 feet after the RNAV approach.

[misd-agin]

A lot of altimeter discussion. VDP is approx 486'/1.6 nm. The picture is at approx 50' and .3-.5 nm. An altimeter setting has nothing to do with getting that low while in visual conditions.

Allegedly report of wind shear which is why there was a delay before subsequent approaches were attempted.

[Escape Path]

For all this talk about wrong altimeter setting...it's a sea level airport. The pressure differential (between std and actual) is not that high, and the altitude error resulting from a missed (with a D not a T) altimeter setting is way less than the altitude at which they ended up at.

Some other fellow posters have commented about some sort of distraction after breaking out at minima. This seems the explanation that satisfies me the most. Murky weather, breaking out at or near minima, both pilots looking out for the runway, PM forgetting to monitor instruments, altitude vs horizon difficult to assess due to weather plus it being a beach/sea airport certainly doesn't help with the optical illusions.

For the sake of the argument, yes they did what they're supposed to, i.e. go around, but I certainly would like to know how they ended up in such scenario, so we all (or me at least!) can avoid or at least identify such scenario before getting to such little error margins...

Oh and btw, to me at least, the microburst/windshear scenario doesn't quite work with me, given what I've seen both on video and also the metar I saw from one of the articles I've seen regarding this hmm, occurrence.

Regards, your Caribbean/Latin American jet pilot

[DaveReidUK]

For all this talk about wrong altimeter setting...it's a sea level airport. The pressure differential (between std and actual) is not that high

Are you seriously suggesting that the difference between standard 1013.2 mb and on the day QNH 1019 mb (about 150') isn't significant on approach ?

and the altitude error resulting from a missed (with a D not a T) altimeter settingmisset: to set, adjust or calibrate something incorrectly :ugh:

[WhatsaLizad?]

Maybe someone can set up a approach to landing rating website.

Enjoy the link, pretty cool.

Maho Beach Cam - SXM Airport Cam on St Maarten (http://www.mahobeachcam.com/)

[RAT 5]

For the sake of the argument, yes they did what they're supposed to, i.e. go around,

Given that, I presume, they had 500' set in Baro and that there would have been GPWS call out at +100 & minimums, I wonder what caused them to make a GA so low? If they went below MDA, that's one thing. An altimeter mis-setting might be 150'; that still leaves them 350' above the waves, but as someone said the error would likely put them high. So what instigated the GA? Some guys say they did what they should have, correctly; therefore there is no case to answer. Hm? They should have done it much earlier!
So what else happened? They sure as heck didn't bust out at minimums, see the water so close and think this was not a good idea and then GA. Something happened between the Baro call out of "minimums" and the decision to GA. From the photo that seemed to be quite a longtime. Meanwhile the RA was reading very low. How do WJ fly an NPA? Was PM looking for the runway and PF inside? Were they flying manually and both pilots looking outside wth no-one 'managing the office'? Were they in V/S & automatics with both pilots looking outside?
In most of my Ops PF looks inside & PM looks outside nearing minimums. At minimums if PM does not see the visual reference and call visual PF makes a GA: never looks outside. No hesitation. Both pilots scratching around at minima, both looking outside, no-one managing the office, manual flight or V/S, going pass "minimums not visual" recipe for...............

[ACMS]

Could be similar to Lion Air in Bali, where they didn't go around soon enough to avoid landing on the water........

[Aluminium shuffler]

Escape path, altimeter error is not limited to forgetting to set QNH on transition. They could have been passed/misheard an incorrect QNH and set 1029 instead of 1019, for example. I've had that happen a handful of times, and was fortunate to remember the pressure in the weather brief or have got a Volmet or ATIS that said something different, catching the mistake. Perhaps this crew didn't have the same luxury of a cross check. It fits with why they went below real altitude minima heads-in, why the ADSB shows no major deviation, and fits with the most common cause for such incidents. It's all circumstantial, but don't shoot the idea down without evidence to the contrary.

[DaveReidUK]

It fits with why they went below real altitude minima heads-in, why the ADSB shows no major deviation

The ADS-B does show the deviation, as it is designed to do..

No matter what QNH you set the altimeter to, it has no effect on what's sent by the transponder.

[Herod]

All this talk about mis-set altimeters. Whatever happened to "Rad Alt live, altimeter check"? Particularly at a sea-level airport.

[Aluminium shuffler]

In seven operators, I've never seen anyone use it as a crosscheck, Herod. Rad alt and baro alt seldom match, really just over the sea and Norfolk, so (probably) nobody has an SOP to do that.

[FullWings]

In seven operators, I've never seen anyone use it as a crosscheck, Herod. Rad alt and baro alt seldom match, really just over the sea and Norfolk, so (probably) nobody has an SOP to do that.
We do, although unless you’re over the sea or flat ground there’s not enough information on the chart to tell much more than yes, there’s something underneath you.

Back to the incident, I too am perplexed as to how they ended up as low as they did if they were in constant visual contact with the runway & slope guidance. Must have been four reds for a while but corrective action only taken when within seconds of flare height over the ocean.

[16024]

Rad alt alive crosscheck:
Our lot do it as well.

[smith]

You saying this could be similar to the THY 737 at AMS where the rad alt was faulty and put it into retard flare. At least this time somebody noticed the drop in speed.

[PJ2]

FullWings, re, "Must have been four reds . . .", I wondered too. I haven't yet finished reading the entire thread so perhaps the question is dealt with earlier in, but the Airport INFO chart shows nothing regarding visual vertical guidance installations.

Also, I saw nothing regarding night approaches on 10, (not permitted on 28, nor in IMC).

[safetypee]

PJ / FW, " four reds ". " something beneath the aircraft ".
This assumes that PAPI was visible sometime after 'first contact'. Furthermore this poses the question, contact with which feature.
Conventional overland NPAs require visual contact with the runway environment, which can be interpreted as not requiring contact with the runway, and in extreme no approach lights.
Overwater NPAs such as this approach, then the immediate coastline may have been seen, but nothing more. This could be similar to a classic night 'black hole' illusion where the focus of attention is on a single dominant feature, resulting a low visual approach.
Also that when the PAPI should have been visible were the conditions suitable to immediately determine 'red' etc.
Thoughts?

[RAT 5]

In seven operators, I've never seen anyone use it as a crosscheck, Herod. Rad alt and baro alt seldom match, really just over the sea and Norfolk, so (probably) nobody has an SOP to do that.

Oh dear; another item thing that used to be called airmanship and SA, but now requires an SOP so that pilots act like airman. Disappointing that standards have dipped so low.

[Herod]

Rat5, are you suggesting that an altimeter check is a bad practice? Yes, I concede baro and rad alts will only agree over the sea, but even in other situations it does give a prompt to check that both baro-alts are set to the same figure, generally before you get dangerously close to terra firma. But in this case even more so, since they would agree within a few feet of one another.

[Chuck Ellsworth]

SOP.

Paint by numbers so all artists are at the same level.

[PJ2]

Hi safetypee;

Indeed: what was considered "contact" for this particular approach and what internal guidance and secondary (confirming) information was being used to verify on-slope/off-slope? The investigation will determine that. From what I know, WJ has a robust safety culture.

Retired now but our operation specified the meaning of "contact" for both VMC & IMC conditions and it was much like you describe - minor differences.

Along with the external vertical guidance, I think that good clues that can verify height vs. distance to go are also internal, from the ND, set to the lowest scale, and then using the usual 3:1 ratio, (a thousand feet out, 300ft height above the threshold or 300ft on the RA, and multiples of, etc., roughly), and descent rate vs. ground speed, (again for others looking for the "rules", a rough 3deg descent path can be determined thus: add a zero to the ground speed, divide by 2. eg. 140kts x 10 = 1400 / 2 = 700fpm).

[Capn Bloggs]

Google Earth shows what looks like a PAPI installation at the start of the Aiming Point marking. There's also some type of installation (or foundations) at the 300m markers.

I would be very surprised if regular Hi Cap operations would be permitted with no visual or GS guidance available, especially there with an over-water approach. We (RPT) are simply not permitted (CASA rule) to operate without slope guidance of some type for more than 7 days.

[Capn Bloggs]

Conventional overland NPAs require visual contact with the runway environment, which can be interpreted as not requiring contact with the runway, and in extreme no approach lights.
Dodgy Brothers Incorporated... :)

Drawing a long bow to interpret Macdonalds, then the beach, then the roundabout then the threshold as the runway "environment", if you know what I mean (going a bit overboard, I know). Our AIP says "“visual reference” means the runway threshold or approach lights or other markings identifiable with the landing runway clearly visible to the pilot".

[PJ2]

Capn Bloggs - yes, your observations occurred to me also...it would be surprising not to have some vertical guidance - I just couldn't find that confirmed by the current Airport chart, that's all. I'm sure someone with experience into the field will come forward to answer the question.

Found a stock photo of the approach - PAPI installed. Symbol didn't seem to be on the chart, but that's what "Retired" means...

[RAT 5]

Rat5, are you suggesting that an altimeter check is a bad practice?

Quite the opposite. In Line Training & Line Flying I used to demonstrate the X-check of RA 2500' & bro made sense knowing where you were. It was not a perfect match due terrain, but if you had SA you could make sense of it. My post was this: this addition to help SA should be airmanship and it's sad if it is only does by those who have an SOP to tell them to do it.
In many airlines the RA EGPWS blurts out an alert and the crew respond like parrots without thinking. That is the consequence of many SOP call outs I've experienced. They really were a Parrot Pantomime.

[Skyjob]

Agreed RAT 5.

A simple crosscheck of radio altimeter simply makes crew aware they are now 2500' Above Ground Level and this should be resembled by the Altimeter taking into account Elevation underneath aircraft at time of activation.
Another tool to prevent Blunder Error in QNH settings...

[Aluminium shuffler]

Such cross checks are fundamental airmanship, and I don't think anyone could legitimately criticise anyone for performing them. However, they are not in typical SOPs, and the point has been made in thread after thread about the demise of airmanship and the rise of SOP dogmatism. No-one in their right mind likes it, but that is the modern culture almost everywhere. With inexperienced trainers, only recently promoted to command months before getting a training ticket and only a few thousand hours in their book becoming the norm, it's not going to get better, either.

[CONF iture]

PAPI on both sides for rwy 10 :

_a1oKJWZ29A

Also confirmed by the airport chart.

[RAT 5]

Such cross checks are fundamental airmanship, however, they are not in typical SOPs, and the point has been made in thread after thread about the demise of airmanship and the rise of SOP dogmatism.

Opening paragraph of any SOP manual should read, "Airmanship at all times is an SOP."

but I take your point.

[Herod]

Opening paragraph of any SOP manual should read, "Airmanship at all times is an SOP."

Rat5. I have to agree with you. I can't remember whether the altimeter check was SOP or whether it was just something I did. I've been retired over twelve years now, and things slip out of the mind.

[Skyjob]

"A significant number of operating practices allow the discretion to the Commander to decide how the flight should be flown. These are characterised with the need to exercise sound judgement and prudent assessment and may be referred to as sound operating practises (included under the more general heading of airmanship during an earlier period)."

[PJ2]

Re photos of the airport, yes, found earlier as posted above.

Re, "Also confirmed by the airport chart."

The PAPI information is not on the Jepp Airport chart. The info is on the approach plates, just below the profile section.

Herod, yessir, ten years retired and stuff does slip away!

[FullWings]

PJ / FW, " four reds ". " something beneath the aircraft ".
This assumes that PAPI was visible sometime after 'first contact'. Furthermore this poses the question, contact with which feature.
Conventional overland NPAs require visual contact with the runway environment, which can be interpreted as not requiring contact with the runway, and in extreme no approach lights.
I don’t know about at MDA but the PAPIs were very likely visible during the latter stages of the approach. Why? Because on the airport video you can see the 737 on finals for both approaches, so the vis was good enough. The PAPIs are lit on the video as well.

For us all red or all white visual slope guidance is a mandatory go-around below 1,000R because the approach is unstable (some exceptions).

[JW411]

In my last company (I was there for 19 years) the "Rad Alt live - 2500 feet" with a cross check from the other pilot was an SOP call. Making sure that both Rad Alts agreed was particularly important on an LVP approach.

It made perfect sense to me and cost absolutely nothing.

By the way, I used to go into St Maarten with the DC-10. We always landed to the east and took-off to the west. It was not difficult as long as you had done your homework. The length of the runway and the hill at the eastern end were the main problems. Most of the time we could make JFK with a full load but sometimes the tailwind on take-off would mean a quick refuel at San Juan.

[CONF iture]

The PAPI information is not on the Jepp Airport chart. The info is on the approach plates, just below the profile section.
The PAPI information is also included on the Jepp Taxi charts if you don't wish to call it "Airport chart".

[F.bar]

The 737 was so close from the water maybe becouse the pilot doesn't calculate well the speed or alttitude. The problem was he did the go around very late. I can't understand how he could not see the lights indicated by the altitude

[aterpster]

PJ12:

The PAPI information is not on the Jepp Airport chart. The info is on the approach plates, just below the profile section.

It certainly is, on the 10-9A page, not the airport diagram side but the side with runway info and takeoff minimums. If the PAPI or VASI has limitations as less than standard distance or less than standard beam width, that info will be shown on the "takeoff info continued" page (usually the 10-9A page).

The info on the approach chart does show the PAPI and ALS, but is quick-reference info as opposed to the airport/takeoff pages.

[Escape Path]

Are you seriously suggesting that the difference between standard 1013.2 mb and on the day QNH 1019 mb (about 150') isn't significant on approach ?

misset: to set, adjust or calibrate something incorrectly :ugh:


I didn't say that. What I meant was that 150 ft below minima is certainly higher than what they ended up flying at.

Regarding misset, my mistake, English is not my first language and haven't seen it written like that before. Though mis-set would probably be easier to understand for a non-native English speaker.

@Aluminum shuffler: you're right, I didn't mean to dismiss the whole wrongly set altimeter theory altogether, and surely they could have misheard an altimeter setting. However, if the pilots were familiar with flying in the Caribbean, an altimeter setting higher than say 1020 mb (30.14 inhg) at a sea level airport in the Caribbean is unlikely and should have raised an eyebrow. That's a big IF though.

I do keep the radio alt in scan once it becomes alive, and although in some mountainous airports (like several Andean ones...) it doesn't help much if you don't have some context or knowledge of the terrain around the airport, it's pretty obvious it's more than useful at a sea level airport.

With the info we have, I'm still biased to both pilots looking outside (or getting distracted somehow) when breaking out and no one looking inside. It still doesn't paint the full picture as a 3° path should look familiar to two commercial jet pilots, even if no PAPI. Surely the weather on this approach couldn't make that assessment any easier, but at least a rough "3° visual path" could have been "calculated"

[PJ2]

:ok:, thanks aterpster.

[bluesideoops]

Dadanawa, you seem to be speaking the most sense here, backed up with numbers. If the MDA is 500' at 1.5nm or 700' at 2.0nm as you suggest, then it would be very easy for a 737 at a low thurst setting to lose several hundred feet if hit by a microburst or downdraught. It would take a few seconds to spool up and go-around which is what it looks like in the video. That weather was moving towards the airport (don't know if a frontal system or just a band or rain showers) and I have had experiences flying through a 'curtain' like that where there was a sudden downdraught and sometimes changes in wind velocity/direction (horizontal windshear too). If you were in IMC and breaking out on an approach, this may not be a hazard you are anticipating especially as the weather band on the weather radar may not appear to be moving. It could also be that the windsock situated half-way down the runway, may still be showing the runway as favouring the opposite wind as the weather over the sea may not yet be affecting that far inland. I think they got caught in something like windshear an responded appropriately, another few miles out and it would have been a non-event. The closer you get to terra-firma, the more significant downdraughts and windshear become and are sometimes an unseen danger.

[Ru55]

Can people explain why the Truck heading towards the main runway in this video isn't being given more credit for a go around decision?

https://www.youtube.com/watch?feature=youtu.be&v=0uPTdKwWo78&app=desktop

[GearDown&Locked]

The closer you get to terra-firma, the more significant downdraughts and windshear become and are sometimes an unseen danger.

Anyone who has flown to FNC (LPMA) will surely know this, but in this particular case it's something to be expected even on a calm day. On other airports given the lack of recent episodes, you might be more relaxed, and more prone to be caught off-guard.

[Capn Bloggs]

Good wet-runway landing...not.

[AerocatS2A]

Can people explain why the Truck heading towards the main runway in this video isn't being given more credit for a go around decision?

https://www.youtube.com/watch?feature=youtu.be&v=0uPTdKwWo78&app=desktop

Are you suggesting that if it wasn't for the truck being there, they might have continued their approach?

May I remind you what that approach looked like?

http://i17.photobucket.com/albums/b79/mlab601/WestJet_zpstcjz6lls.jpg

[Mapleflot]

Could be similar to Lion Air in Bali, where they didn't go around soon enough to avoid landing on the water........

Hmm now you've also reminded me of the Turkish 738 at AMS.

[Aluminium shuffler]

That was on the correct profile until they stalled due to a radalt failure affecting the autothrottle and piss poor pilots. Whatever happened to this Westjet is unrelated to the Turkish.

[RAT 5]

The 2nd landing was with a 'healthy' margin beyond the threshold, compared to the bigger visitors; so for a smaller cousin it was perhaps acceptable. But back to my question, which only the crew can answer: what did they do differently the 2nd time? They seemed to have worse vis e.g. the rain, but flew a better profile for glide path to the runway. Why? I'm assuming they flew both approaches on autopilot. I'm curious what they did differently to execute so different a profile. That is how we can learn from this. That is what this discussion should be about: what did they do wrong and then how did they correct it. This is a learning process not a blame process.

[brak]

Paid attention? Took them 45 minutes to collect themselves.

[oleary]

That is simply not true. Read the thread.

[paperHanger]

Looking at that video ... and looking at the photo posted at the beginning of the thread, surely no one is suggesting they were taken of the same approach on the same day? The cloud cover, rain, approach angle are completely different. It's solid cover with rain on the video, broken and sunny on the photo .. the sea state is calm ... it would have been somewhat more lively in that storm etc ...

[AerocatS2A]

Which video are you looking at? The video from the beach and the photo match up nicely while the one from the airport shows rain and wind. Conclusion? There was a squall over the airport that shows in the webcam video but the approach itself was clear.

[pattern_is_full]

Looking at that video ... and looking at the photo posted at the beginning of the thread, surely no one is suggesting they were taken of the same approach on the same day? The cloud cover, rain, approach angle are completely different. It's solid cover with rain on the video, broken and sunny on the photo .. the sea state is calm ... it would have been somewhat more lively in that storm etc ...

I've got to assume you've never operated in the tropics.

A single tropical Cu - (not Cb, Cu; your basic 5000 x 5000-ft puffball) - can drop a dense rain shaft that is less than a mile thick, yet totally impenetrable to vision. And with 20-kt constant trade winds, can move on 5 miles in 15 minutes.

Living and working in San Juan, just over yonder from TNCM, it was almost a daily afternoon event to go from severe clear and sunny, to the middle of a downpour that cut viz to tens of meters, and back to bright and sunny again, in a period of 10 minutes, as one single cloud decided to cut loose. With rain so heavy that within 15 seconds you might just as well have jumped in the sea - soaked to the nether regions of the underwear. And flooded gutters and streets - localized to a 4-block area.

Not that you can't get longer or wider-spread storms as well. But in the tropics, there is nothing at all abnormal about the visual difference between those two approaches - not only on the same day, or 45 minutes apart, but even just 15 minutes apart.

[India Four Two]

During my one-and-only flight to St. Martin, we experienced exactly the circumstances described by pattern_is_full. A 30 minute hold waiting for a rain shower to move away from the approach, followed by straight forward approach and landing in VMC and a disembarkation onto a hot and steamy apron.

[safetypee]

_._._._, "non event", certainly not.
All events are important; their significance depends on what individuals are willing to learn.

The first approach could have been an unusual deviation within normal operations, towards the accepted boundary of procedural approach systems and/or human performance.
We should remind ourselves that NPAs still involve significant risk which although often masked by precision-like systems, still depend on human monitoring and recovery. Thus a GA is 'normal', an approved response to a deviation. Celebrate, and learn from the success of human intervention.

Alternatively there was an unexpected or undetected external disturbance, where crews are again expected to compensate for deviation or error; the crew did, well done.
What we must learn is how the crew performed to achieve this success, or at least how they managed to do their best in the perceived situation.

We could understand how the situation developed, hopefully to identify similar occasions and avoid the circumstances. Of greater importance, we need to understand how the crew recovered the situation, because this behaviour could help in similar misjudged situations and a range of other 'normal' situations which require detection and recovery from operational variability.

Flying is not a narrow band, straight line operation. It is necessary for operational / human deviations in order to achieve objectives, - safety and economics. The skill in flying involves how we manage those deviations, our awareness, adaptability, and knowledge of safe boundaries; what we should learn from this event could help improve these aspects.
If the industry can achieve more successes ( recovery / adaptation ) in normal variable operation, then there should be fewer occasions where the outcome is less than we expect.

[ShotOne]

May I ask why so many "experts" are spending their energy to "prove" (or not) they were below MDA when it's very clear the aircraft pictured is in visual flight? Hint: it is normal and necessary to descend below MDA in 100% of landings!

[No Fly Zone]

No! WestJet did NOT "Almost put one in the Water." The 'event' was a very ordinary Go Around, photographed from an unusual angle. No more and No Less. Please do not believe everything that some fools post on the internet. The more dramatic the story, the less likely it is to be true. Think first and perhaps believe later. We, of all populations, are expected to know better. (Hey... At least this one hit the wire. have lost two others today, including one cited in a PM that will now make no sense, even of it did before. Cannot recover, so there is nothing to edit. Not my day and perhaps I should go back to my book.) Thanks for your note, PJ2.
and... As others have noted as well, that is already a long and very low approach. If you've ever seen a few from ground level, they really do look horrible, especially as flown by VLA (Very Large Aircraft.) While possible, I'm not aware of any modern jet having taken a swim while on approach there, they just LOOK bad at times. Further, our colleague, Jet Jockey A4, can be a bit dramatic at times. It happens. NFZ

[PJ2]

. . . it is normal and necessary to descend below MDA in 100% of landings! Yes it is, but not that far out from the threshold.

The airplane was low - below a 3deg descent path, period.

https://www.youtube.com/watch?v=uN3Fd0x0FoQ (https://m.youtube.com/watch?v=yNhAYKM-7LQ&feature=youtu.be)

Why it was low will be determined by the airline's and the local regulator's investigations.

Please do not believe everything that some fools post on the internet. Yes, I certainly concur with that part of your post and have taken the advice.

[DaveReidUK]

I'm not aware of any modern jet having taken a swim while on approach there, they just LOOK bad at times.

I suspect that may not read the way you intended it to.

[AerocatS2A]

https://m.youtube.com/watch?v=yNhAYKM-7LQ&feature=youtu.be

The B737 is clearly at threshold height when no threshold is even thinking of possibly considering entering the picture. To suggest that this was somehow "normal" is just ridiculous.

[FullWings]

As others have noted as well, that is already a long and very low approach.
Only if you get it wrong, as the instrument approach gradient is 3degs as is the PAPI from the charts I’ve seen.
To suggest that this was somehow "normal" is just ridiculous.
I have to agree. Also, we only see the 737 after it has started a GA and is on an upward path... :eek:

[clunckdriver]

What a load of :mad: have been written on this thread, mostly authored by those who have little or no tropical flying experience, or by those who received a" PFO "letter from West Jet. The crew did it right, get a life!

[atr-drivr]

Please explain how.

[PJ2]

clunckdriver;

Some thoughts on reading thread contributions.

It is long past time to take this profession back from "internet experts".

Regarding what is written on these threads, there remain a few professional pilots here who haven't given up on discussions and who can separate some of the nonsense written by those who don't do the work from those who know their stuff.

Unless a newbie shows authentic curiosity and genuine interest, the rest just gets ignored, and, where particularly painfully-wrong, the poster ends up in the "ignore" bin. There is too little time to correct disingenuous queries.

The remaining dialogue is still very good for two reasons:

1) It is good for those who are starting out and who need to read and hear from those who have done it for a while, and,

2) It is good for those who have done it for years to disagree on all aspects of the profession and industry, and to support such disagreements with facts and references from professional sources, partly so that those just starting out don't get the idea that they know it all off the bat, especially when they see those who have done it for decades disagreeing both courteously and professionally. The strongest ego is quiet and sure of itself while being mindful of its weaknesses; the loudest ones are incertain.

The sign of someone who knows aviation and is a professional airman (man or woman), is being up-to-date with a thorough knowledge of their SOPs and as much as they can get about their airplane from the FCOM. The other sign is someone who reads the accident reports and reads some of the flight safety conference proceedings, just like other professions do.

How to disagree is as important as asking the right questions.

[Escape Path]

https://m.youtube.com/watch?v=yNhAYKM-7LQ&feature=youtu.be

The B737 is clearly at threshold height when no threshold is even thinking of possibly considering entering the picture. To suggest that this was somehow "normal" is just ridiculous.
+1

PJ2, my respects good man. That is the basis and objective of this forum.

Clunckdriver, certainly there was something abnormal about that event, and I'd surely like to know what happened so I can be on the look out. You cannot learn all the lessons by yourself, goes the saying.

If anyone says 30 minutes is not enough to go from apocalyptic downpour to sunny skies, certainly they don't have experience flying in the Caribbean and should take a second or two before posting, so they don't look rubbish to those who do have such experience.

Now, where were we?

[RAT 5]

One would assume ATC would have been looking out of the window, perhaps with binoculars; they could have some input, but perhaps Prune is not on their radar. What is certain is that some guys in Westjet know about this. One would hope a safety report was filed and thus the safety foundation, one of which is based in Canada, will be able to publish a meaningful & educational report for the rest of us to learn from.

[M-ONGO]

May I ask why so many "experts" are spending their energy to "prove" (or not) they were below MDA when it's very clear the aircraft pictured is in visual flight? Hint: it is normal and necessary to descend below MDA in 100% of landings! Visual flight or not, the aircraft should not be flown below the PAPI though should it? Sure, we've all done it. Legally speaking though, it makes an interesting case. If only lawyers could see colours other than black and white... Obviously, there are some airports where the 'till a lower altitude is necessary for a safe landing' applies more than others, following the glide/PAPI's at these airports in certain types can lead to an underwear change at the other end, but the book says they are legal.

Just last week I was in TNCM, following an RNAV arrival. ATC were certainly calling us at every waypoint confirming altitudes then fully established - I wonder if this were the case prior to this incident. The controller certainly had her work cut out, she was pretty busy with both ends of the runway in use.

[Selfloading]

Passenger view https://www.youtube.com/watch?v=uN3Fd0x0FoQ

[slast]

At first sight this resembles many other events, a lot of which have been catastrophic.

In that case, likely contributory factors could include

* The crew did not expect and prepare for a “minimums” approach, because the weather was reported basically “good” prior to top of descent. The weather is reported at ToD is 05018KT 9999 FEW014 BKN035 24/21 Q1018 A3008 NOSIG - that it doesn't sound like a very demanding approach if you're coming from winter in Canada to a Caribbean holiday resort, does it?

* Then, though there are now obviously some big showers around, a lot of the approach might be only marginally IMC anyway. Approaching MDA which is 2.5 miles out from the runway, the sea surface may well have been easily seen, so the pilots assume the runway would soon also become visible.

* With less favourable conditions now becoming very evident, there may also be a strong desire to get on the ground, rather than wait and possible divert with all the attendant disruption.

* So maybe both pilots just stayed head up looking for the runway. They're over an almost featureless water surface that's is merging into cloud and rain with no clear horizon.

* With the autopilot disconnected, that precipitation close to the runway decreases visibility, and maybe leads to an illusion of pitching up. In any case the descent rate increases without the pilots realising it, as both are focused on trying to see the runway and neither is concentrating on the instruments.

*Then something - radio altimeter callouts? peripheral vision? triggers the realisation that the surface is actually very much closer than it should be

* triggering low altitude go-around.

Optimistic/inadequate planning + deteriorating weather + minimal visual cues + plan continuation bias + absence of uninterrupted instrument monitoring to touchdown = a predictable nasty fright, but luckily, this time it's not as bad as LionAir in Bali or many others.

[Capn Bloggs]

I think Slast has hit the nail on the head. The wobbly FlightRadar record of the first approach supports that. The second approach was much more polished.

[Jet Jockey A4]

Finally a CADORS for this incident was entered on March 27th (yesterday).

http://i17.photobucket.com/albums/b79/mlab601/CADORS_zpsxmzvqhgb.jpg

[DaveReidUK]

Worth noting that the "Further Action Required: No" is Transport Canada's categorisation of the event.

The Canadian TSB, on the other hand, opened an investigation on 17th March, categorising the event as a Class 3 - defined as:

"Individual occurrences that do not meet the criteria of Class 2 occurrences may be investigated when
1. there is significant public expectation that the TSB should independently make findings as to cause(s) and contributing factors; or
2. there is potential for better understanding the latent unsafe conditions contributing to a significant safety issue; or
3, a government representative so requests (pursuant to Section 14(2) of the CTAISB Act); or the Board must do so to meet its obligations or commitments."

[slast]

JJA4, so since TC also says on its CADORS main page "The Transportation Safety Board of Canada is the official source of aviation accident and incident data in Canada" does this mean that TSB is going to look into it any further or not? Which of them decides?

[Jet Jockey A4]

Well I hope we get some additional investigation and info at a later date from the TSB.

The latest video from onboard the aircraft while on the first approach is a bit perplexing.

[Jet Jockey A4]

JJA4, so since TC also says on its CADORS main page "The Transportation Safety Board of Canada is the official source of aviation accident and incident data in Canada" does this mean that TSB is going to look into it any further or not? Which of them decides?

Yes they can...

The TSB is independent of Transport Canada and may indeed continue to investigate the incident.

However, if they do continue to investigate and produce a report of the incident, the TSB will only be able to suggest/recommend that certain measure are taken to avoid another such event...

They have no authority to penalise the crew or the company for their actions (assuming something was wrong) because only TC can do that and since TC is already on the record that "no further action is required", nothing is going to come out of this.

[DaveReidUK]

They have no authority to penalise the crew or the company for their actions (assuming something was wrong) because only TC can do that and since TC is already on the record that "no further action is required", nothing is going to come out of this.

Are you saying that TSB Safety Recommendations directed at Transport Canada are routinely ignored ?

[9 lives]

Are you saying that TSB Safety Recommendations directed at Transport Canada are routinely ignored ?

Perhaps "ignored" is too absolute a term, how about "considered, but not acted upon by regulatory change....". 'Doesn't mean TC is not thinking about how to make things better....

[Jet Jockey A4]

Are you saying that TSB Safety Recommendations directed at Transport Canada are routinely ignored ?


Well, no I'm not saying that but I'm sure not all recommendations directed at TC from the TSB are implemented.

In this case (and I'm speculating here) because I don't have all the facts, it seems this crew was caught off guard by deteriorating weather and continued an approach below the minimum with the results we have seen.

So what can the TSB do about it? I suspect nothing. What can they write in a report that would change anything since rules are already in place to cover minimums?

I'm not even sure by the time the TSB got word of this incident that the DFDR was available to them with data from the incident.

It would be up to TC to say that the crew "busted minimums" and handout whatever penalties for such an infraction which would likely be a little slap on the wrist.

If TC is not going to get involved (which seems to be the case), then it would be up to the chief pilot of the company to take action, again I'm afraid it's just another slap on the wrist.

[slast]

Interesting situation.... I guess what's happened here is that no-one in either authority was concerned (or even aware) until the publicity started. TC then jumped in and took a quick look, decided "nothing to see here, move along". Then the TSB says "hey maybe there is".

If it turned out that for a silly example the aircraft had a runaway nose down pitch trim that the crew heroically overcame and didn't think worth mentioning (prob: 10-6) then I guess that TC would have to reconsider their "no further action" judgement! Re other more likely causes - it will be interesting to follow this little story.

[oleary]

What a load of :mad: have been written on this thread, mostly authored by those who have little or no tropical flying experience, or by those who received a" PFO "letter from West Jet. The crew did it right, get a life!

What clunckdriver said.

[45989]

This thread must represent the apogee of the trainspotters here.
Never seen so much :mad:
Classic was the muppet who put a nine year old jepp plate up.
Flight simmers
FYI current same plate is dated 27/1/17, then only real pilots would have these........

[aterpster]

I corrected "the muppet" in my post #48.

[underfire]

Well, looking at the video from the bar near the end of the runway, that was pretty damn low. Not only can you see the wake, you see the pressure wave in front of the wings, so they were in ground effect.

http://i63.tinypic.com/5u3p2.jpg

Looking at a relative comparison from the video from the shore, the red line is the wingspan 112' (34m) and the green line is the distance from wheel to the water surface. The comparative lines show at this point, just as the aircraft begins GA, (and still a distance offshore) appears to show about 52' (16m) above the water surface.
https://www.youtube.com/watch?v=fXCJPHRErZ8

Should be about 50' (15m) at threshold.....

Best to review the actual video to see the water surface, etc used for the comparison.

In regards to the procedure designers adding the decent profile, that is of course, how the procedure is designed, what is charted is up to the State and the particular criteria it has decided to use.

From a previous post in this thread, this needs to reference the threshold, not beginning of pavement. TCH here is 50 feet.

http://www.jacdec.de/WP/wp-content/uploads/2017/03/2017-03-07_C-GWSV_B738_WJA@StMaarten_lowAppr_MAP1.png

EDIT: BTW, looking at the Frozen ac, they used about 1925 lbs of paint for that.....pretty good hit on the MLW! For Canada, that is like 7 pax w/cheese....

[_Phoenix]

Waving hands to the champion:
new video (https://www.facebook.com/tsai.anlee/videos/10212423716411153/)
It's ridiculous the instrument approach system of this famous western international airport.

[alph2z]

Interesting situation... ...TC would have to reconsider their "no further action" judgement! Re other more likely causes - it will be interesting to follow this little story.

Yes, it's an interesting situation. Just at DH/MDA, finally get a visual, call out a visual, and then the weather shuts the view of the runway.

What do the airline's SOPs, FARs, legal, TSB, TC, FAA, NTSB, boeing procedures, airbus procedures, etc.... say about this ??

[Left Coaster]

Pretty sure that almost ALL of them require a GO AROUND if visual clues are lost below DA/DH... (seriously, you had to ask?)

You have to figure that this thread has gone about as far as possible and has been beaten to death by supposition...Let it go folks, there's nothing more to look at...move along.

[YRP]

Why is there discussion that the crew lost visual with the runway?

There is video from the far end of the runway that shows the airplane visible on the first approach. If we can see them...

Sure they got low, maybe the precipitation gave some illusions, maybe they were distracted. Not great and not the usual of course. But there is no indication they couldn't see the (presumably well lit) runway.

[Jet Jockey A4]

@ YRP...

Again look at the latest video (in post 193 above) and tell me that's a normal approach? Tell me you really think that being that low (50-75' AGL) that far back from the runway threshold is normal?

Yes they executed a missed approach, the only sensible thing to do in their situation and saved the day in the process. The question is why did they get into that position in the first place...

Again looking at the latest video, pay attention to the "Go Around" and you will notice that the aircraft goes into the clouds at perhaps 200 to 300 feet AGL.

What if there was a cloud base like the one on the GO Around on the approach?

Wouldn't that indicate that they pushed the limits?

[RatherBeFlying]

The last two videos, one by pax, the other head on from beach show precip.

Possible refraction
Possible downdraft with precip
Well below CAVOK, but within limits
Height perception above​ water surface difficult, especially in prevailing viz

~= a lined up Emmenthaler

Did the EGPWS pipe up? If not, why not?

[slast]

There is video from the far end of the runway that shows the airplane visible on the first approach. If we can see them...

... they can see us." Not necessarily so at all.

[golfyankeesierra]

@YRP
Lights? It's only the box and the papi. No approach lights there.

You really can't say that because we see them, they saw us. The place is a big sum of multiple visual illusions.
Difficult depth perception, approach over water, threshold on the beach, displaced threshold, short runway, no approach or centerline lights, no horizon because of the hills behind it, runway at an angle on the coast and high MDA after which LNAV and vertical profile go a different way (which can be a distraction at the least or a short moment of vertigo if you don't expect it). And that's in good weather.
The airport is a lot of fun but needs a good preparation and briefing.

[RAT 5]

G.Y.S. and others: no one has answered the question which others are asking, as to how they arrived in this predicament. That is very pertinent; was it a crew mess up, a system malfunction, an NPA training issue, a....etc.
Also, what stimulated the GA? It was VMC. Was it the EGPWS, was it the sudden awareness of the RA, was it losing sight of the runway, was it the sudden realisation they were going for a swim.
Were they visual at MDA and on profile? If so, and the a/c was in trim and stable (i.e. was the approach flown on automatics?) then doing nothing should have put the a/c closer to the correct spot than this.
So, what did they do to arrive in the wrong place and why was the GA so late. For the Canadian CAA to not investigate further to find these answers is almost a dereliction of duty to the rest of us and the pax.

[FullWings]

RAT 5 I agree. It’s not about pillorying the crew, it’s about understanding what led them down the path they went so we can avoid repeating it. In a “just culture” we should be able to learn from others in a non-judgemental way, unless of course it was gross negligence or cowboy flying that got them there.

I’m at a loss (having flown a lot in the Tropics) to explain how the aircraft got to where it did without prior intervention. What guidance was being followed? Instrument? Visual? Mix of both? Neither? They obviously didn’t set out to crash but they were not far away from it, IMHO. Hopefully we may see a report at some time which may answer a few questions...

[Jwscud]

For the Canadian CAA to not investigate further to find these answers is almost a dereliction of duty to the rest of us and the pax.

As I understand it, the TSB (the safety/accident investigation chaps) are investigating. The local CAA (enforcement) are not. That strikes me as the right call. Both I am sure will have seen the QAR record and it strikes me as precisely the right call that this will end up in a bulletin for us all to learn from.

[aterpster]

Both I am sure will have seen the QAR record and it strikes me as precisely the right call that this will end up in a bulletin for us all to learn from.

I don't share your confidence.

[underfire]

Rat, I believe people are questioning how they got to that point, but there is no information, certainly not from WJ. The WJ blog has been all over the place on the incident.
To be that close to CFIT or CFIW, that far out, multiple systems must have all been screaming at them. The ac is not that old, (even has the split scimitar winglets), so it should have all the bells and whistles...

Close to the water, a delay in the GA, then 40 minutes in hold? Why was that?

There we also lucky the was not the usual flotilla of boats out there on the flightpath, they were certainly at mainsail ht!

This has made news all over the World, so it should be reviewed, and sorted as to why and how this happened.

[PJ2]

aterpster, re, "I don't share your confidence.", where do your doubts lie? Tx...

underfire, what "multiple systems" and "all the bells and whistles" do you have in mind that would be "screaming"? I'm not being flippant/sarcastic and am asking seriously, what warnings would you expect, and why? I am assuming you're a B737-800 pilot with training & knowledge to comment reliably. Thanks.

[alph2z]

Airbus A333

... During the daylight approach to Runway 24R in the presence of a thunderstorm just north of the airport, the crew was advised that the lighting on Runway 24R was out of service. This was the only runway in operation. During final approach, meteorological conditions changed from visual meteorological conditions to instrument meteorological conditions. On short final, during the approach to Runway 24R, using the instrument landing system, the aircraft entered a heavy rain shower and encountered a right crosswind exceeding 20 knots. The aircraft deviated from its path before touching down to the left of the runway centreline at 1234 Eastern Daylight Time. Following the landing, the left rear tire of the left main landing gear left the hard surface of the runway and travelled approximately 600 feet before regaining the runway. The aircraft returned to the centreline before taxiing to the terminal gate, where the passengers exited. Three runway edge lights were damaged. ...

Aviation Investigation Report A14Q0155 - Transportation Safety Board of Canada (http://www.tsb.gc.ca/eng/rapports-reports/aviation/2014/a14q0155/a14q0155.asp)

EDIT: Following excerpt added with some bolding by me

3.1 Findings as to causes and contributing factors

During an approach in the presence of a thunderstorm, pilot-induced oscillation led to the aircraft being in a left bank as it crossed the runway threshold which, combined with a strong right crosswind, resulted in a rapid drift to the left very close to the ground.
Once the aircraft crossed the runway threshold, the intensity of the precipitation increased suddenly, such that the pilot flying (PF) had reduced visual references. Under these conditions, the PF did not detect the lateral movement of the aircraft in time to correct the drift before the outboard tires of the left bogie landed in the grass.
Given the absence of runway lighting in reduced visibility conditions, it was difficult for the pilot flying to detect the lateral movement of the aircraft over the runway and therefore to prevent the runway excursion.
A lateral wind shear generated by a downburst to the north of the runway suddenly increased the aircraft's drift to the left during the landing flare.
Runway 24R was not closed in instrument meteorological conditions, even though the runway lighting was not working. As a result, the runway was not equipped with the lights required to enable crews to clearly distinguish the lateral confines of the runway.

3.2 Findings as to risk

If airports are not equipped with a low-level wind shear alert system, crews landing there may not be aware of the presence of downbursts or microbursts, and therefore may be exposed to the risk of approach-and-landing accidents.
If a crew is unable to verify landing performance in heavy rain conditions involving a risk of hydroplaning, there is an increased risk of runway excursion.
If the "landing" response to the "minimum" calls reinforces the notion that landing is assured, there is a possibility that preparation for, and the decision to, go-around could be affected, increasing the risk of a landing incident or accident.
If the rain repellent system is unavailable or not used, there is an increased risk, in heavy rain conditions, that crews will lose the visual references necessary to avoid a runway excursion.
If a crew does not consider the consequences of multiple threats, there is a risk that pilots will continue a landing under conditions that are not favourable.
If the aircraft is drifting near the ground and pilots place the aircraft in low-energy landing regime, there is an increased risk of runway excursion.
If crews are not trained to retake the controls at very low altitudes or during the low-energy landing regime, there is a risk that, in the event of a problem, the pilot monitoring will not have time to identify the problem and take the appropriate measures.
If TC does not take action to develop the clear standards on avoiding thunderstorms during approach and landing called for in Recommendation A07-01, approaches in the presence of convective weather will continue, exposing aircraft to the multiple, unpredictable hazards associated with thunderstorms.
If occurrence sites are not preserved, there is a risk that evidence essential to identifying factors that contributed to an occurrence will be lost.
If dispatch is not aware of an aircraft communications, addressing and reporting system transmission failure, there is an increased risk that critical flight information is not received by the crew.

3.3 Other findings

... The runway excursion was not the result of a premature crab angle reduction manoeuvre, which is often associated with landing incidents in crosswind conditions.


Ignore history and history will repeat itself over and over again.

[aterpster]

aterpster, re, "I don't share your confidence.", where do your doubts lie? Tx...



Apparent age-old failure to remain at, or above, the appropriate minimum altitude until "in the slot."

I look forward to an official report removing my doubts.

[underfire]

The ground prox/taws would have warned below glideslope, perhaps terrain closure rate, and too low...
Depending on how they dropped, descent rate near terrain
Warning for closure rate
The altitude annunciator would have been giving them the periodic, and the 50 foot..There is altitude callouts in 10 foot increments, they certainly heard the 100 foot increments, but that is custom set, so not certain how often altitude was annunciated, but I bet they had 50 foot called.
The is Boeing, so the system uses a 500'ROC at FAF, and tapers down, (AB is 400' ROC at FAF) so they would not have had the required obstacle clearance and it would warn of imminent ground contact...
They would have the forward looking capability, based on the FAF, threshold location, thus the predicted flightpath, and this would have been yet another warning, more than 2 dots below flightpath.
It would have given a premature descent alert when that far below flightpath.
IF windshear had occurred, that would have been another warning.

EDIT: approach over water, there is supposed to be an additional obstacle area added for the transient boat traffic, unclear if this is added to their database.

[PJ2]

aterpster;
Thanks...figured something like that [-(

I've used the FR24 data to plot the first & second approach paths, much like someone has done earlier in this thread, but a 3deg descent path (red line, from the threshold, out) is drawn in, and 150' added to all FR altitudes as per an earlier discussion on altimetry & ADS-B.

The flight path may appear a bit lower than it was because the aircraft was slightly left of the inbound course after MAPON, and Google Earth takes such perspective into account, as many here would probably understand.

The steady altitude during the hold also indicated "2450". Adding 150' to that gives 2600ft which is the MHA for the hold and for all inbounds so it seems reasonable to do so.

150' appears too much at the lowest point of the first approach; I think the airplane was less than a hundred feet above the water at lowest point but the investigation will provide that information - that level of fine-tuning for a baro correction is too much for FR24.

Anyway, here are some trial results...nothing scientific about it at all:

https://photos.smugmug.com/photos/i-rkXkjSm/0/M/i-rkXkjSm-M.jpg https://photos.smugmug.com/photos/i-jqtBsB4/0/M/i-jqtBsB4-M.jpg

Second approach:
https://photos.smugmug.com/photos/i-z8wQ9Bm/0/M/i-z8wQ9Bm-M.jpg https://photos.smugmug.com/photos/i-psx6J7S/0/M/i-psx6J7S-M.jpg

[PJ2]

underfire;

Well, interesting. We'll see if any of those warnings were active any time during the approach. As aterpster states, age-old failure to maintain minimum until in the slot. Lion Air, UPS @ Birmingham come to mind, (and I believe there were no warnings in the UPS accident).

[underfire]

PJ2,

Interesting flightpath profile information, which program are you using? Are you just plotting the .kml file from FR?

I thought that the ADSB showed 0 altitude when the ac was on final (per earlier posts)

What is the lowest altitude that you are showing,is this the 150' add that you used?

Note that there is a 50' TCH on the flightpath, not a direct line to TCH 0.
So you know, ADSB data reports altitude in 25 foot increments, and has latency factors in the system, to which there is about an 8 second delay.
It is notoriously inaccurate in reporting altitude on final approach due to the descent rate and kalman reporting latencies, especially if there is rapid descent, a turn or crosswinds.

[Capn Bloggs]

Underfire, an impressive list of warnings. Obviously the crew must have ignored all of them.

[DaveReidUK]

I thought that the ADSB showed 0 altitude when the ac was on final (per earlier posts)

No, FR24 showed zero, which isn't quite the same thing. :*

I suspect that where a non-corrected ADS-B altitude becomes negative (i.e. in this case at the points where the actual height was less than 150'), FR24 dumbly substitutes null/0 values, so those can't be trusted.

So you know, ADSB data reports altitude in 25 foot increments, and has latency factors in the system, to which there is about an 8 second delay.
It is notoriously inaccurate in reporting altitude on final approach due to the descent rate and kalman reporting latencies, especially if there is rapid descent, a turn or crosswinds.Other than the 25' granularity, altitude reported by ADS-B should be as accurate (subject to adjustment for QNH) and timely as your altimeter, given that both are coming from the same source and subject to the same errors.

Where did you get the idea that there is a delay of anything like 8 seconds (not that we're particularly interested in absolute time values in this instance) ? Where is the data being buffered in the meantime ?

[underfire]

Other than the 25' granularity, altitude reported by ADS-B should be as accurate (subject to adjustment for QNH) and timely as your altimeter, given that both are coming from the same source and subject to the same errors.

and subject to the ADSB reporting sequencing.

Where did you get the idea that there is a delay of anything like 8 seconds (not that we're particularly interested in absolute time values in this instance) ? Where is the data being buffered in the meantime ?

As we know, the system shows where the ac was, not where it is, the kalman filter estimates where the ac is.
8 seconds is what is typically used in the latency calcs, and the information is buffered in the INS. (the net has significant papers on latency issues with GPS and aircraft)
Each low band sat signal takes about 3 seconds to receive, (and in realty, it may be 5 seconds with correction) with multiple sats required, it takes a while to receive all of them, process them.
The kalman filter, tracks the data, determines the ac location where it was, and interpolates the data to where the ac actually is. That calculation has a latency of about 8 seconds. Within that 8 seconds, if there are changes to the horizontal flightpath, such as a turn, or even crosswinds, or vertically with descent, the data will not be accurate.


After all of that, the ac systems uses a lookup feature from the internal database for altitude. Depending on the manufacturer, that methodology is vastly different. That is then compared with the rad alt and baro data, and viola, that is your altitude as reported. (ohhh the algorithms) You want it to figure out the descent profile, in a turn, (a 3d spiral) using a lookup feature to an internal database with an 8 second delay? oh yea.

The descent on final approach, again based on 8 seconds latency, will not be accurate at all, even with continuous descent. Too much happens in 8 seconds for the ADSB data to be accurate, ie how much has the ac descended in 8 seconds based on an 8 second delay with 25 foot reporting....

The data transmitted through ADSB is far different that what you have on the ac, in both reporting and granularity.

[golfyankeesierra]

Underfire, an impressive list of warnings. Obviously the crew must have ignored all of them.
Agree Bloggs, don't think there would be a lot of warnings at all.
Certainly no "glideslope" warning, there is no glideslope (ILS) in St Maarten!
Also no "terrain" warning (terrain closure); within a defined area around the airport (not sure how big that exactly is, but I guess they were to close) you don't get those; otherwise you could never land;)
For a "sink rate" you would need around 1000FPM at low altitude, doesn't look like it on the video..
And a "windshear" warning would warrant an aggressive maneuver; the go around looks very gentle too me. Doen's look like this one either..
The "minimums" call is at 500' (or 700'), that awareness call had already passed..

They should have had the 100' Radio alt call though. Perhaps that was the trigger for them. At about 100' you should see the threshold disappearing under the nose; I guess they had a lot of water instead.. Suddenly that creepy feeling comes up...

[DaveReidUK]

After all of that, the ac systems uses a lookup feature from the internal database for altitude. Depending on the manufacturer, that methodology is vastly different. That is then compared with the rad alt and baro data, and viola, that is your altitude as reported. (ohhh the algorithms) You want it to figure out the descent profile, in a turn, (a 3d spiral) using a lookup feature to an internal database with an 8 second delay? oh yea.

ADS-B almost always sends baro altitude not GPS height, so none of the above is relevant. Once you're above the transition altitude, what it sends will be the same, give or take the 25 feet, as you are seeing on your altimeter.

No satellites or databases involved, just a bit of aneroid magic. :O

You can easily verify that if you visit your local airport with an ADS-B receiver and watch aircraft taking off. You will see the altitude readout changing within a second or so of the wheels leaving the runway.

Not that any of this is relevant to the WestJet - we know the data that it sent, we know the QNH correction factor, so unless you're suggesting that the positional and altitude data were out-of-sync with each other then we can be pretty confident that the flightpath plots we've seen represent what actually happened.

[PJ2]

underfire;

I created the images using the basic FR24 kml data in Google Earth (free version), with modifications as described in my post.

Method:
You can right-click-copy each/any of the FR24 waypoints and paste the text into Notepad to see both lat-long & altitude, which follows right after the lat-long data.

You can also create sloping lines to simulate descent paths by modifying the height (in meters), at one end of the line thus created. A slope can be calculated using trig functions. For the 3° descent path on the SXM10 I created a line from the runway threshold extended to a point 10NM out and saved it in Google Earth so it appeared in the Places list on the left side of the map. I right-click-copied that line and pasted the text into Notepad. I calculated the height of the line (ASL) using trig:
tan (3°) x d = h, or, 0.052407 x 60000 = 3144.46ft, or 958.4m ASL.

In Notepad, I changed the line's end height of 0m to 958m then Selected-All and pasted the changed kml over top of the original one in the Places list, (it actually gets inserted just below the waypoint over which you paste).

Because GE defaults to "Clamped to Ground" when drawing any lines, I right-clicked on the line to get the drop-down menu, and selected "Properties > Altitude". I selected "Absolute" which releases it from "clamped" and becomes a slope from a height of 3144ft (the correct height 10NM out on a 3° slope) to about 12', the height of the SXM airport. To be precise one could add that 12' (4m) in and program the end of the line to 962m, but none of this is that accurate, as discussed elsewhere. It takes a little experimentation and intuition.

To be clear, I concur with other posters regarding "no warnings" at that stage of flight. I believe that if you flew these aircraft you'd know that and the fact that GPWS glide slope warnings do not monitor RNAV approaches. As stated, we'll see what the investigation says; I think there are some interesting theories here.

[underfire]

Agree Bloggs, don't think there would be a lot of warnings at all.
Certainly no "glideslope" warning, there is no glideslope (ILS) in St Maarten!
Also no "terrain" warning (terrain closure); within a defined area around the airport (not sure how big that exactly is, but I guess they were to close) you don't get those; otherwise you could never land
For a "sink rate" you would need around 1000FPM at low altitude, doesn't look like it on the video..
And a "windshear" warning would warrant an aggressive maneuver; the go around looks very gentle too me. Doen's look like this one either..
The "minimums" call is at 500' (or 700'), that awareness call had already passed..

They should have had the 100' Radio alt call though. Perhaps that was the trigger for them. At about 100' you should see the threshold disappearing under the nose; I guess they had a lot of water instead.. Suddenly that creepy feeling comes up...

I did not say they had all of these, but depending on what was going on, these are the warnings.

ADSB usually broadcasts both baro and geometric altitude. Because of all of the issues with baro, many automated ATC systems use geometric.

There were claims early on from WJ about a rapid descent, hence a possible windshear warning, and we dont see videos as to how far out they were that low, hence the other warning that may have occurred for terrain closure....

the question was how many warnings could there be, and that is a list of possible ones.

This ac should be EGPWS, which does use the terrain clearance floor and terrain awareness, based on the information of terrain and obstacles in the database.The EGPWS uses a geometric altitude that blends improved pressure altitude calculations, GPS altitude, radio altimeter, and terrain and runway information to eliminate the reliance on human data input. The look ahead feature uses a 60 second timeframe, so being that far out and that low, the 60 second look ahead would have picked that up.
They were pretty far out when the videos and images were taken, so it is likley that obstacle clearance protection was not met.

[Capn Bloggs]

I did not say they had all of these, but depending on what was going on, these are the warnings.
That's how your post read.

May I suggest that if you don't know, then either don't say or write a clear disclaimer that you are hypothesising. I would wager there are plenty of readers on here who don't know, and reading your missives will give them the wrong ideas, especially since what you wrote above about warnings is largely irrelevant to this incident.

They were pretty far out when the videos and images were taken, so it is likley that obstacle clearance protection was not met.
Is this is based on detailed knowledge of the system or just a hypothesis? They didn't look "too far out" to me. I would doubt very much if the EGPWS would have been squawking at them.

[underfire]

Well, as I stated, we dont know how far they were out, but the one still images, shows the turbulence on the water from the ac going on for quite a while, as I stated, that is an unknown. The person taking the image also stated that she saw the aircraft flying very low, grabbed the camera and took the image, so it appears it was for a while, and the FR ADSB data concurs.

You, nor anyone else, has no idea of what transpired, and everyone is hypothesizing.

The EGPWS systems are different, and when WJ initially started with these, many procedures that had been in use, began setting off the alarms. The way the system forward looks, and understand the glidepath between the FAF and threshold, and the associated ROC. This has nothing to do with ILS. Many obstacles and terrain which were not previously an issue, became issues and had to be added to the database.
There were issues with procedures in Adelaide with QANTAS for the same reasons.

Do you really think that that distance from threshold, at about 50 feet from a surface, there would be no warnings, especially with a 60 second forward looking capability?

Do you really think the altitude calls were not annunciated by the system? minima that far out or 50 that far out?

EDIT: Just so you know, ATC systems in AUS use geometric, not baro altitude from the ADSB broadcasts.

[Mostly Harmless]

I never knew there were so many armchairs in the world.

[alph2z]

That's how your post read.

May I suggest that if you don't know, then either don't say or write a clear disclaimer that you are hypothesising. I would wager there are plenty of readers on here who don't know, and reading your missives will give them the wrong ideas, especially since what you wrote above about warnings is largely irrelevant to this incident.


Is this is based on detailed knowledge of the system or just a hypothesis? They didn't look "too far out" to me. I would doubt very much if the EGPWS would have been squawking at them.

You and many others I agree with; and I know Kalman filters and their derivation of. Mixed up english and topics.

[Capn Bloggs]

Many obstacles and terrain which were not previously an issue, became issues and had to be added to the database.
You're talking nonsense. The E in EGPWS is purely GPS & database-based. If an obstacle is not in the database, the box won't squawk that you are going to hit it! It n to a forward-looking radar.

There is the "off-airport" mode, but as I said, based on what I have seen using the system for many years, I doubt that it would have given a warning.

[aterpster]

Bloggs,

You're talking nonsense. The E in EGPWS is purely GPS & database-based. If an obstacle is not in the database...

What he is saying is correct. Obstacles have been added with better surveys and better data subsequent to the inception of EGPWS. And, there is a "peaks and obstacles" option for additional $$$$ that provides greater accuracy and fidelity of terrain near airports where RNP AR approaches are in use.

There is a possibility that the EVA 777 that came dangerously close to Mt. Wilson near KLAX the past December did not have the many antennas on Mt. Wilson in their EGPWS database. One of those towers is almost 1,000 feet, agl, atop the highest point on that mountain.

[PJ2]

More than necessary precious TC time have been spent on investigating a non-event just to satisfy the ever growing public hunger for sensationalistic news related to air transport. You would not be offering such views if the outcome had been only slightly different as in the UPS CFIT accident at Birmingham and the Lion Air CFIT accident near Bali.

You can't argue both ways, as in, "only give it precious TC time if it was an accident". None of us has such predictive capabilities as to determine how close to an accident this and others like this was, and so must handle events like this one as serious in order to find out why it happened.

Even with the most sophisticated equipment which assists crew in building and maintaining a high degree of situational awareness, it remains a puzzle why this kind of event continues to occur. So I disagree with your somewhat polemical comments.

[Jet Jockey A4]

@ I-FORD...

Don't forget the TSB opened an investigation into this incident.

[AerocatS2A]

Bloggs,



What he is saying is correct. Obstacles have been added with better surveys and better data subsequent to the inception of EGPWS. And, there is a "peaks and obstacles" option for additional $$$$ that provides greater accuracy and fidelity of terrain near airports where RNP AR approaches are in use.

No, what he is saying is not correct. What he said was that with EGPWS some obstacles and terrain started giving warnings and then had to be entered into the database. If they weren't in the database then they can't have given warnings because the EGPWS wouldn't have known about them. Whatever Underfire's point is, he is not expressing it well. Maybe he meant that obstacles and terrain that were already in the database started giving warnings with EGPWS that weren't given with GPWS and that the system logic had to be adjusted to allow for them, but that's not what he said.

[Jet Jockey A4]

From DaveReidUK's post 181..

"The Canadian TSB, on the other hand, opened an investigation on 17th March, categorising the event as a Class 3 - defined as:

"Individual occurrences that do not meet the criteria of Class 2 occurrences may be investigated when
1. there is significant public expectation that the TSB should independently make findings as to cause(s) and contributing factors; or
2. there is potential for better understanding the latent unsafe conditions contributing to a significant safety issue; or
3, a government representative so requests (pursuant to Section 14(2) of the CTAISB Act); or the Board must do so to meet its obligations or commitments."

As of today I don't know what the status of the TSB's investigation is on this event.

[aterpster]

No, what he is saying is not correct. What he said was that with EGPWS some obstacles and terrain started giving warnings and then had to be entered into the database. If they weren't in the database then they can't have given warnings because the EGPWS wouldn't have known about them. Whatever Underfire's point is, he is not expressing it well. Maybe he meant that obstacles and terrain that were already in the database started giving warnings with EGPWS that weren't given with GPWS and that the system logic had to be adjusted to allow for them, but that's not what he said.
Perhaps that's what he meant. I took it that way because perhaps I was reading too quickly.

[DaveReidUK]

I thougth that TSB investigated EVENTS, in this case the crew applied the right decision, went around and saved the day, so no event or Outcome, as the TEM teaches us.

You might want to have a read of ICAO Annex 13, in particular the definition of "serious incident" and the examples given of events that fall into that category.

[RAT 5]

I thougth that TSB investigated EVENTS, in this case the crew applied the right decision, went around and saved the day, so no event or Outcome, as the TEM teaches us. TC is the right agency to investigate the issue as they are paid to set the rules to PREVENT events or outcomes. If an attitude, behaviour, knowledge or else was applied in a situation and solved it that's exactly what it is requested by good airmanship no need for further investigation, the system reacted as expected so why keep digging? It looks just voyeurism to me.

I think that is over simplified. If a crew is dumped, unexpectedly and due to no fault of their own, in an undesirable situation and they escape from it, then job well done. If a crew, due to inappropriate actions, puts an a/c into an undesirable situation, and then, as they see a disaster unfolding, they decide to escape from it, then perhaps not quite so job well done. It would be necessary, from a learning point of view, to analyse the events completely and not just dismiss it as a non-event.

[RealUlli]

(Disclaimer: SLF)

I've seen some mentions of a possible microburst. However, I haven't seen something I noticed in the video taken from the Sunset Bar:

There seems to be a squall there, the sunshades are whipped around quite a bit. Their direction also indicated quite a bit of tailwind for the plane.

Is that irrelevant or am I really the only one to spot it? It might also be the normal wind there (I seem to recall the METAR said 080@18 - is the beach at the approach of 09 or 27?)

I've recently been in the Windward Islands on a sailboat, the squalls described in another post are quite annoying. They come up, dump a ton of water on you, 5 minutes later they're gone again.

[aterpster]

The authoritative data are contained in the DFDR and hopefully has been read by the Canadian aviation authorities.

[roybert]

For those interested the TSB has just released the report into this incident. http://www.bst-tsb.gc.ca/eng/rapports-reports/aviation/2017/a17f0052/a17f0052.pdf

[Airbubba]

Thanks for posting that. :ok:

They went down to 40 feet off the water before the go around. :eek:

And, once again as in SFO, the Canadian CVR is missing:

Because the occurrence was originally assessed by WestJet as a non-reportable event, the cockpit voice recorder and the digital flight data recorder data were overwritten and were not available to the investigation.

[FullWings]

Really good report, well worth a read. A lot of very relevant HF stuff in there as well.

An interesting detail is that they were cleared and flew the approach in vis well below minima but were unaware of that because they weren’t told by ATC. They also went visual before they could see the airport or runway (allowable), then misidentified another feature as the runway. Lowest point 39’AGL 0.3NM from the threshold.

Lots of things all lining up and nearly putting them in the water, classic “holes in the cheese” stuff. Plenty of learning points here...

[aterpster]

I don't understand how the DFDR was overwritten. I thought they retained data for a relatively long period.

[Jet Jockey A4]

Thank God there was a QAR on board that aircraft or else we would have never known the truth about how close that came to being a crash.

For Westjet to declare this a "non incident" and allow both the DFDR and CVR to be erased just proves you can not hold a company to police itself.

I would like to know why if the crew had no visual contact with the runway and had no visual height reference above the water, why they did not one of the pilots (PNF) monitor the Rad Alt and why it took a minimum of two EGWPS warnings before they decided to go around?

Finally now that the truth came out thanks to the QAR, what did Westjet do to the pilots and what steps have they taken for this not to happen again?

[Airbubba]

Finally now that the truth came out thanks to the QAR, what did Westjet do to the pilots and what steps have they taken for this not to happen again?

Don't know about the pilots but this WestJet corrective action plan is mentioned in the report:

Following the occurrence, WestJet conducted a company investigation and developed a corrective action plan. The plan included

• a safety communication letter (Flight Safety Flash), sent to all pilots, explaining the incident and providing information regarding possible challenges and threats at the Princess Juliana International Airport (TNCM),

• revision of the route and aerodrome qualification document for TNCM,

• provision of a flight safety briefing on the incident to all crews at the annual ground school, and

• design of a new instrument approach at TNCM.

The revised route and aerodrome qualification document for TNCM contained the following additional information:

• **Extra diligence required in reduced visibility operations.** Build-up of land and buildings North of the runway can cause illusion of false runway, leading to lower approach angle. Cross check your visual track against our FMC [flight management computer] to ensure you are lined up with the actual runway.

• Due to difficulty in acquiring visual confirmation of runway in reduced visibility conditions, it is recommended to consider abandoning the approach if you do not identify the runway ¼ mile back from the MAP [missed approach point].

[Jet Jockey A4]

Thanks I must have missed the plan while reading the report... At least they took some steps to correct the situation.

[pattern_is_full]

Also just a reminder that in the tropics, even one cute-looking puffy Cu can dump enough rain to ruin your whole day, without much warning from the weather folks. And be gone 5 minutes later. Be prepared...

[India Four Two]

What surprises me is that the TSB made no comment about WestJet deciding that this was a non-reportable incident.

[lomapaseo]

What surprises me is that the TSB made no comment about WestJet deciding that this was a non-reportable incident.

Many are judgement calls as/until more data and interviews are conducted. If no intent to deceive was noted the government will let it go.

I've been involved in some where I came in a couple of days late and then rang up the phones. Th aircraft was back in service and the recorders were still with it.

[A4]

Multiple “TOO LOW TERRAIN” and a GA - not a mandatory reportable occurance? Interesting SMS.

A4

[FlyingStone]

Is it just me or do we have a trend here with Canadian operators continuing approaches below DA/MDA without sufficient visual references? First AC at Halifax, now this...

I agree with A4, very interesting safety culture WestJet seems to have.

[FlightDetent]

I don't understand how the DFDR was overwritten. I thought they retained data for a relatively long period. Ours keep the regulatory minimum of 25 hrs. I have a hunch the limit may have changed to 120 hours for the newer units.
An empty QAR would normally have the capacity to hold 4 weeks of flying.

[scifi]

Flying directly towards a white hotel, that they mistook for the runway...
Brings a whole new meaning to 'You have reached your Destination.'
.

[BluSdUp]

Wow!
In 2017 this is still possible!
Were to begin?
Someone pointed out here is lots of point we can learn from!
Like what?
At DP or Minima , You have to have the Runway or associated light in sight, Old news!!
Ground contact, hills or Shoreline does not count!! As per Rules and OPS manual!
They were told 2000m vis , but claim they did not hear.
What the dickens were they doing below say 200 feet without the threshold and runway infront of them.
Simple, they had lost the plot, the lateral to a certain extent and concentrating on that , the vertical totally.
This can NEVER happen on a non-precision approach. That is part of basic training, never mind a 150 kt 737-800.
Without the EGPWS they would have hit the water. 100% for sure.
Super scary.
To be continued.

[RAT 5]

What surprises me is that the TSB made no comment about WestJet deciding that this was a non-reportable incident.

Is an Airmiss a reportable incident in Canada? SFO was similar to an airmiss, albeit one target was on the ground. This was a severe groundmiss, again one target was not airborne, but you get my drift. If a 1nm airmiss is reportable, but a 40-60' near crash is not, that sounds confusing double standards.

Regarding the continuous descent after MDA & MAP; at the worst, if no immediate GA due no visual reference, is a level off at MDA. It also smacks of 2 heard outside searching for the target and no-one minding the office. That is a MCC training culture and company technique. In my airlines, even if they might have been SOP nannies, they had very strict crew duties during NAP's, even all approaches. No confusion and IMHO were excellent. Never 2 heads out or in.