An almost new SWISS Boeing 777 suffered wing damage in São Paulo on Tuesday after high winds allegedly shifted a mobile stair unit. However, while there were rain and storms at São Paulo Airport on Tuesday, recorded wind speeds do not appear to be high enough to have caused the stairs to shift on their own - unless someone forgot to apply the brakes.
Wayward stairs punctured wing on SWISS Boeing 777-300
The incident was reported yesterday in AirwaysMag. That was based on a social media posting by Twitter user AeroHoje, who shared photos of the incident. AeroHoje says a ladder hit the wing of the SWISS Boeing 777-300ER. As a result, the Zurich bound flight was canceled.
Zeroing in on the photos, it's clear to see where the stairs hit the wing slats on the right-wing. You can also see where the wing has been punctured by a protruding bolt on the stair unit. The plane appears to be away from the gates when the incident occurred. Photos also reveal the weather was inclement at the time. While there were storms in the Sao Paulo area on Tuesday afternoon, wind records indicate wind speeds at Sao Paulo Airport on Tuesday did not exceed 24 kilometers per hour.
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A busy plane gets grounded
The plane involved in the incident was HK-JNK. It is one of 12 Boeing 777-300s SWISS sends around the globe. This particular plane is the second youngest of the 777-300s, arriving at the airline in November 2019. The plane cost SWISS International a cool US$300 million, so they probably aren't too thrilled about the wayward stairs hitting their plane.
HB-JNK came into São Paulo from Zurich, operating LX92 on Monday, October 19. The return flight, LX93, was slated to push back from the gate in São Paulo at 17:10 local time. But the plane remains on the ground in Brazil after the incident with the stairs.
The grounding follows a busy week for the aircraft. Before Zurich, the Boeing 777-300 had made return trips to both Johannesburg and Bangkok. If it was any other airline type, Swiss has a few spare planes parked they could roll out to replace the damaged one. But in a piece of bad luck, all 12 of SWISS' Boeing 777-300s remain in service.
Did someone forget to apply the brakes?
The mobile stair unit involved in the incident was the type that is towed. A look at various similar examples available for sale via manufacturer's online catalogs suggests its net weight is around 1.5 tonnes, give or take 10%. Normally, it would take fairly high winds to move such a heavy piece of equipment.
The mobile stairs are on wheels, and a braking system is standard to hold them in place. The aircraft was parked when the incident occurred. In the absence of typhoon grade winds, one likely cause is that the brakes were not applied or not applied properly. A moderate wind gust may have hit the mobile stair unit side on, where there's some aluminum paneling, causing the stair to swing around and collide with the Boeing's wing.
No doubt, some intense discussions are going on between SWISS and their ground handlers in São Paulo to work out who's at fault and who will pay for the damage.