What happened
On August 14, 2012, an Air India Charters B737-800NG, registration VT-AXE, was completing a scheduled flight from Dubai to Mangalore. During the approach to Runway 24, the aircraft encountered heavy fog and low-altitude clouds, which significantly reduced visibility.
As the aircraft transitioned from instrument meteorological conditions to visual meteorological conditions, the pilot-in-command disconnected the autopilot at approximately 245 feet above the airfield. Following this disconnection, the aircraft entered a nose-down attitude, and the rate of descent increased sharply to approximately 1,056 feet per minute. The aircraft subsequently struck the undershoot area—a compacted earth surface—approximately 105 feet before the runway threshold. This initial impact caused the aircraft to bounce roughly 20 feet into the air before a second touchdown occurred on the runway. The heavy impact resulted in a vertical acceleration of 3.253g, exceeding the standard limit.
The investigation
An inquiry by AAIB India examined the flight data, cockpit voice recordings, and physical wreckage. The investigation focused on the flight crew's actions during the transition from automated to manual flight and the environmental conditions at Mangalore Airport. Investigators reviewed the maintenance logs, the crew's training records, and the airport's visibility monitoring procedures. The investigation also looked into the damage sustained by the aircraft, which included punctures to the left horizontal stabilizer and significant damage to several main wheel tyres caused by debris and loose stones from the runway's construction material.
Findings
- The primary cause of the incident was incorrect control inputs by the captain during the transition from IMC to VMC, compounded by a loss of depth perception due to fog.
- The flight crew failed to initiate a go-around despite the aircraft flying below the glide slope and experiencing an unstable approach.
- The pilot-in-command maintained a nose-down pitch to seek better visual cues, which prevented proper monitoring of the descent rate.
- There was a lack of effective Crew Resource Management (CRM), as the first officer was distracted by instructions to look for runway lights rather than monitoring instruments.
- The aircraft's landing gear and left horizontal stabilizer sustained damage from striking loose stones and soil in the undershoot area.
- The airport lacked a modern, automated RVR system, relying instead on manual visibility measurements which are subject to human error.