What happened
On June 30, 2019, an Air India Express Boeing 737-800, registration VT-AYA, was involved in a serious runway excursion at Mangalore Airport. The flight, arriving from Dubai, initially attempted an ILS approach to runway 24 but was forced to execute a go-around after a GPWS glideslope warning and a sudden downdraft.
During the subsequent second approach, the aircraft failed to meet stabilized approach criteria. The aircraft was high and fast, eventually touching down approximately 902 meters ahead of the runway threshold. Due to a delayed deployment of thrust reversers and the use of manual braking instead of autobrakes on a reported wet runway, the aircraft could not stop within the available pavement. As the runway end approached, the pilot turned the aircraft to the right to avoid the end of the runway, causing the aircraft to exit the paved surface via the taxiway E intersection and come to a halt on unpended ground about 80 meters from the runway edge.
The investigation
AAIB India investigators examined the flight data, cockpit voice recorder, and aircraft components. The inquiry focused on the flight crew's decision-making during the unstable approach and the mechanical application of braking systems. The investigation also reviewed the aircraft's maintenance history and the operator's training protocols regarding tailwind and balked landings.
Findings
- The aircraft was not stabilized during the final approach, maintaining excessive speed and altitude.
- The pilot flying failed to initiate a go-around despite the co-pilot's callouts regarding high altitude and excessive speed.
- A significant delay occurred in deploying thrust reversers, which were only engaged 17 seconds after touchdown.
- The crew did not utilize the autobrake system, relying instead on manual braking.
- The runway surface at the end of runway 24 was wet, which hindered effective deceleration.
- The pilot's indecision between continuing the landing or performing a go-around contributed to the delayed use of deceleration controls.
Safety action
- The investigation noted that the airline lacked specific procedures for managing abnormal situations like runway excursions.
- Recommendations were made to include runway excursion prevention and tailwind landing training in recurrent flight crew programs.
- It was suggested that operators foster a non-punitive culture to encourage pilots to execute go-arounds whenever safety criteria are not met.