St. Maarten: Report on near-splashdown of Westjet B-738

Pilawt

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http://www.tsb.gc.ca/eng/medias-media/communiques/aviation/2018/a17f0052-20180604.asp

Misidentification of runway in reduced visibility contributed to the March 2017 risk of collision with terrain of a WestJet flight in Sint Maarten

Gatineau, Quebec, 4 June 2018 – In its investigation report (A17F0052) released today, the Transportation Safety Board of Canada (TSB) found that unexpected weather conditions on final approach, reduced runway conspicuity, and inadequate flight path monitoring led to a risk of collision with terrain.

On 7 March 2017, a WestJet Boeing 737-800 was operating as flight 2652 from Toronto/Lester B. Pearson International Airport (CYYZ), Ontario, to Princess Juliana International Airport (TNCM) in Sint Maarten with 158 passengers and six crew members on board. It entered a significant rain shower shortly after crossing the MAPON (missed approach point) waypoint. The crew initiated a missed approach 0.30 nautical miles from the runway threshold at an altitude of 40 feet above water. :eek: Once visibility improved, the crew conducted a second approach and landed without incident.

The investigation determined that the runway lights and the visual guidance system (PAPI) had been set at a low intensity during the rain shower that had obscured the view of the airport environment. Both the shower and the low lighting limited the visual references available to the crew to identify the runway properly until the aircraft had exited the rain shower and visibility sharply improved.

The sudden and unexpected poor visibility during the final approach increased the flight crew's visual workload and led to inadequate altitude monitoring. The crew did not notice that the aircraft had descended below the normal angle of descent to the runway threshold until the enhanced ground proximity warning system issued an alert.

After the occurrence, WestJet developed a corrective action plan, including information for pilots regarding possible challenges and threats on approaching and landing at Princess Juliana International Airport. WestJet also revised its Route & Aerodrome Qualification for TNCM with additional information. In addition, guidance on airport lighting system management will be added to the Air Traffic Services operations manual in TNCM by September 2018.​

Video:
 
Had to be Canadian, no American would use the world "conspicuity". Lets hear it for Canada!
 
I don't believe TNCM has any instrument approach procedures, or frankly even any approach procedures. At least Foreflight and AirNav don't seem to have any.

Granted, if there is a "MAPON" or missed approach point, then technically if you lose sight of the runway / airport aren't you automatically supposed to go around? Shouldn't wait for a terrain warning!



Not saying this happened here... but isn't the TNCM approach famous for the crazy low approaches to wow the beach onlookers? You'll often see videos of planes dragging it in from miles away
 
TNCM/SXM has three instrument approaches.
Thanks, I should have clarified, I meant that they don't have any precision approaches so they won't be getting a glide slope (sometimes trying to write and edit messages with speech-to-text gets the better of me!).

I'm pretty sure that at any point after the missed approach point if you lose visual site of the airport environment you automatically have to go around.. basically, the rain squall explanation doesn't really answer why they waited until they got and terrain alert
 
Yay, yet another indisputable reason not to cling to the fence directly under the approach of a 150,000lb/150kt missile. As if the others were not enough. Unless you want to be smeared by a myopic Canajan.
 
Yay, yet another indisputable reason not to cling to the fence directly under the approach of a 150,000lb/150kt missile. As if the others were not enough. Unless you want to be smeared by a myopic Canajan.

No more risky than riding in the airplane I guess

Not convinced:


Make up your mind, Dave. You start out criticizing fence-hangers' risk of being hit by landing airliners coming in low, and when tarheel says that's no more risk than flying in those jets on a low approach, you post a video of idiot fence-hangers behind a jet taking off . . . .

But tarheel is right--if people on the ground are at risk from a low-flying plane on approach, so are the people inside the jet (dramatic videos of take offs don't apply).
 
Thanks, I should have clarified, I meant that they don't have any precision approaches so they won't be getting a glide slope
They were in a 737-800 so they should have been flying the RNAV approach using LNAV/VNAV which gives them a 3.00 degree glide-path that the flight director and autopilot will track. The 737s actually do those approaches very well.

The published MDA is 700'. That would be adjusted to a derived decision altitude (DDA) of 750' and flown like the DA on an ILS. Once below 750' they are on the visual segment. That would be, if I'm doing the match correctly in my head, about 2200' from the runway. I haven't read the report, though I have landed 737 NGs at SXM, but I'm thinking that they were probably inside of that DDA when they lost sight of the runway.

The island airports really aren't designed to be "all weather" airports in the way most airports in the US are. The vast majority of operations are during good VMC. This airport also has an issue with significant terrain close-in on the east end of the runway which impacts the missed approach. There is a 1,555' obstacle just 5nm from the approach end of runway 10 and obstacles of 723', 576', 975', and 1,118' within about 2nm. Youtube has some good cockpit videos of 737s landing and departing that runway.
 
TNCM is historically a bad airport to fly into during poor weather. There has been several crashes that were caused by poor visibility on approach to Runway 10.
 
Thanks @Larry in TN for the write up and explanation, that all makes sense but it still seems peculiar that they needed a terrain alert to initiate the go around. From where the YouTube video starts it doesn't appear as though there's any big rain deluge by that point

Either way, glad it all turned out safe!
 
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