On September 7, 2025, a WestJet Boeing 737-800 flying in from Toronto (YYZ) to St. Maarten (SXM) experienced a firm (but not hard) landing followed by a right main landing gear collapse. This caused the right side to droop and drag on the right engine nacelle as the aircraft slowed to a halt.

All 163 passengers and crew members survived the ordeal, but the immobilized aircraft would force Princess Juliana International Airport to cancel all flights in and out for the next 24 hours. The 16-year-old aircraft (registered C-GWSR) was eventually towed to safety with the assistance of a crane, allowing for a more thorough investigation.

WestJet flight from Toronto to St. Maarten makes hard landing

Officials quickly noted that the landing gear strut has broken away, resulting in significant damage to the wing itself. Some quickly pointed fingers at the pilot flying, assuming that the firmer than usual landing resulting in the gear collapsing, but the Transportation Safety Board of Canada (TSB) has released an update, focusing their attention on the right gear aft trunnion pin.

Trunnion pins are critical components of the main landing gear assembly, connecting the main landing gear to the frame of the aircraft, serving as a pivot for the gear to extend and retract. The pins also bear the bulk of the load during landing, and when the aircraft is on the ground.

According to the report, they discovered that the pin was fractured, and have since sent the broken pieces to the TSB Engineering Laboratory in Ottawa, Ontario for further examination. They also noted that the right main landing gear was overhauled in 2016. The TSB is also investigating previous occurrences involving aft trunnion pin fractures on Boeing 737s. Data from the FDR also indicates that this was not a hard landing event.

This isn’t the first time that a Boeing 737 has a suffered landing gear collapse as a result of a fractured trunnion pin. In the past ten years, there are have five incidents including two Jet Airways 737s in 2015 and 2016, one at GOL 737-800 in 2018, one involving a United Airlines 737-800, and an Alaska 737-800 in 2023.

Looking back at some of the previous incidents, these types of incidents stemmed from improper detection and/or maintenance procedures, resulting in these pins either corroding or suffering unnecessary fatigue, which would later cause premature cracks.

For instance, in 2015, the pin from a Jet Airways 737-800 was discovered to have been corroded as a result of a combination of moisture penetration due to improper re-lubrication techniques, and cracks not being properly detected during inspection. In 2023, the pin on an Alaska Airlines Boeing 737-800 went through improper heat treatment, causing it to become brittle, resulting in the landing gear collapsing due to a broken pin.

The final report will obviously determine what led up to the pin breaking, but I’m sure WestJet is already scrutinizing its maintenance procedures to see what can be improved to avoid encountering a situation like this again.

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