The crew aborting take-off due to tyre failure caused a UPS MD-11F to be written off at Seoul’s Incheon International Airport in June 2016.
A report by the Aviation and Railway Accident Investigation Board says UPS flight 5X61 suffered a runway excursion and nose gear collapse on take-off on 6 June.
The MD-11F, which was bound for Anchorage Ted Stevens International Airport was taking off from runway 33L when the left-hand tyre, number 9 on the central landing gear as the aircraft reached V1 speed after a ground run of 6,413 feet.
Number 10 on the same landing gear also ruptured and vibration and torsion forces caused the lower drag brace of the central landing gear to break, with the drag brace hitting the body several times.
This caused a rupture of the hydraulic system of brake system 1, reducing break efficiency to 48% as the crew rejected the take-off.
With 4,635 feet of runway remaining, the aircraft began decelerating but it required at least 5,500 feet, causing the MD-11F to stop about 1,591 feet past the end of runway 33L, with the nose gear collapsing and engines 1 and 3 contacting the grass.
The aircraft, N277UP, which was built in 1995 and had flown 63,195 hours was written off.
ARAIB investigators noted it is inherently difficult to determine the flight performance after V1 when little information and time is available to decide whether to go or not.
The UPS flight manual states that after V1, rejecting take-off is not recommended unless the aircraft cannot fly, but ARAIB noted it would be helpful if flight crews were given clearer definitions to judge flight performance.
The report says the main cause of the accident was the crew abandoning take-off due to tyre failure.
Limited time and available information, instability of dragging the central landing gear and decreased braking performance were contributing factors.
