Flight History
Air India Express flight IX-812, a return leg from Dubai to Mangalore, was operated by the same crew that had flown the outbound leg IX-811 earlier. The outbound flight landed at Dubai at 23:44 local time. After servicing and refueling, the aircraft taxied for departure at 01:06 local time (02:36 IST). The takeoff, climb, and cruise were uneventful. The captain slept for approximately 1 hour and 40 minutes, during which the First Officer handled all radio communications.
The flight reported position at IGAMA at 05:33 IST and was advised to expect an ILS DME Arc approach to Mangalore. At about 130 miles from Mangalore, the First Officer requested descent clearance, but the ATC controller denied it to maintain separation with other traffic. At 05:46 IST, the flight reported at 80 DME and was cleared to 7000 ft, commencing descent at 77 DME at 05:47 IST. Visibility was reported as 6 km.
Mangalore airport is a table-top runway. According to the AIP India, the aerodrome is located on a hilltop with valleys 200–250 ft beyond the paved surface. Air India Express required that only the pilot-in-command (PIC) conduct takeoffs and landings at this airport. The captain had performed 16 landings at Mangalore previously; the First Officer had operated as copilot on 66 flights there.
Approach and Landing
As the aircraft descended, no recorded conversation indicated the mandatory descent and landing briefing as per standard operating procedures. Around 50 miles from the airport, descending out of FL295, an incomplete approach briefing was noted. At 25 nm, descending through FL184, the aircraft was cleared to continue to 2900 ft. The First Officer requested to proceed directly to Radial 338 and join the 10 DME Arc. Throughout the descent and DME Arc approach for ILS 24, the aircraft remained much higher than normal altitudes.
Handover to Mangalore Tower occurred at 05:52 IST. The tower controller asked the aircraft to report established on the 10 DME Arc. The First Officer showed signs of tiredness, indicated by yawning on the cockpit voice recorder. The tower then requested a report when established on the ILS.
Realizing the aircraft was high, the captain selected landing gear down at approximately 8,500 ft with speed brakes deployed to increase the rate of descent. The aircraft did not intercept the ILS glide path at the correct altitude, resulting in an altitude nearly twice that of a standard ILS approach. During the approach, the captain selected flaps 40 degrees and completed the landing checklist.
At 06:03 IST, at about 2.5 DME, the radio altimeter alerted 2500 ft. The First Officer said, "It is too high" and "Runway straight down." The captain exclaimed, "Oh my god," disconnected the autopilot, and increased the rate of descent. The First Officer queried, "Go around?" The captain called out, "Wrong loc ... localiser ... glide path." The First Officer again called for a go-around and said "Unstabilized," but did not take action to initiate one.
Having visually acquired the runway, the captain increased the rate of descent to nearly 4,000 ft per minute, triggering EGPWS warnings for "SINK RATE" and "PULL UP." The pilots did not report established on the ILS; the tower queried, and the captain prompted the First Officer to reply "Affirmative." The tower cleared the aircraft to land with winds calm.
The aircraft touched down far down the runway, crossing the threshold at about 200 ft altitude at a speed exceeding 160 kt, compared to the target 50 ft at 144 kt. Despite EGPWS warnings and three calls from the First Officer to go around, the captain persisted. The final touchdown occurred approximately 5,200 ft from the threshold of runway 24, leaving about 2,800 ft of paved surface. The captain selected thrust reversers soon after touchdown but initiated a go-around 6 seconds after applying brakes, contravening Boeing SOP. The aircraft overshot the runway and the 60-meter strip, continued into the 90-meter Runway End Safety Area, where the right wing struck the localizer antenna structure 85 meters beyond the RESA. The aircraft then hit the boundary fence and fell into a gorge.
Probable Cause
The Court of Inquiry determined that the cause of this accident was the captain's failure to discontinue the unstabilized approach and his persistence in continuing with the landing, despite three calls from the First Officer to go around and a number of warnings from the EGPWS. Contributing factors included: (1) The captain's prolonged sleep during the flight, possibly leading to sleep inertia and impaired judgment, accentuated by flying in the Window of Circadian Low; (2) The absence of Mangalore Area Control Radar (MSSR) due to unserviceability, resulting in descent clearance at a shorter DME distance, with the flight crew not planning the descent profile properly; (3) Ambiguity in instructions regarding the copilot's authority to initiate a go-around, leading the First Officer to give repeated calls but not take over the controls.