Fatigued Pilots! What Happened to Flight IX-812

Air India’s low cost airline, Air India Express, operates a scheduled Quick Turn Around flight IX-811/812 on Mangalore-Dubai-Managlore sector. The onward flight from Mangalore is at 21:35 H (IST) while the return from Dubai is scheduled at 02:45 H (IST, local time 01:15 H), to arrive at Managlore at 06:30 H (IST). On 22 May 2010, while flight IX 812 was landing at Managlore’s tabletop runway, the Boeing 737-800 aircraft overshot the runway resulting in tragic loss of 158 lives, including 6 crew [1].

The accident was attributed to “the Captain’s failure to discontinue the ‘unstabilised approach‘ and persistence in continuing with the landing,” despite three cautionary calls from the first officer and numerous EPGWS warnings. One of the contributory factors was the Captain’s sleep inertia, having slept through most of the flight, probably accentuated due to flight operations during the Window of Circadian Low (WOCL) [1].

Being a tabletop runway (length = 2450 m or 8038 ft), there is a special qualification requirement by Air India Express: only the pilot in command (PIC) shall carry out take off and landing at Mangalore. Accordingly the captain had to land the aircraft, but evidently there was incomplete approach briefing prior to commencement of descent around 77 DME from Mangalore. The aircraft, making an ILS approach, was still high during descent, as evident from exclamation by the captain, “Oh! My God!” to the cautionary warning by the first officer, “It is too high”, and “runway straight down”. This was despite the captain attempting to retard the air speed by selecting landing gears ‘down’ at 8500 feet altitude with speed brakes deployed and choice of flaps at 40 degree. The first officer had cautioned at 2500 feet and 2.5 DME asking, “Go Around?”; instead the captain chose to increase the rate of descent after disconnecting the autopilot.

But immediately the captain, realising his error exclaimed, “Wrong LOC….Localiser…Glide path”.

The first officer suggested, “Go Around”, and “Unstabilised” but did not himself initiate the action while the crew continued ignoring repeated EGPWS warnings, “sink rate” and “pull up”. The aircraft was descending at 4000 feet per minute! The crew did not confirm having established on ILS approach (Figure), and only when the ATC queried, the captain ‘forcefully prompted’ the first officer to give an affirmative call.

Figure: Glide Slope of IX-812 [1]

As per eye witness accounts, the aircraft was high on approach and touched down farther ahead on the runway, crossing the runway threshold at around 200 feet with speed of 160 knots (compared to conventional 50 feet and 144 knots, respectively). Short of touchdown, the first officer called out the third warning, “Go around Captain” and “We don’t have runway left”. Yet the captain persisted with the fatal approach in unstabilised conditions, touching down about 5200 feet from threshold, with only 2800 feet of paved runway remaining to stop the aircraft!

Within 6 seconds of applying brakes after touchdown, the captain intiated a ‘Go Around’, contravening aircraft manufacturer, Boeing’s SOP. The aircraft overshoot runway 24, into runway end safety area, continuing downwards, breaking the boundary fence and falling into a gorge. Aircraft was destroyed due to the impact and fire, with fatal outcome.

Read More

• Who Failed in Crash of Flight IX-812? (Physiological Factors)
• Who Failed in Crash of Flight IX-812? (CRM)
• Who Failed in Crash of Flight IX-812? (Organisational Failures)

Reference

1. Report on Accident to Air India Express Boeing 737-800 Aircraft VT-AXV on 22nd May 2010 at Mangalore. DGCA, New Delhi. 2010

Acknowledgement  Image courtesy Wikipedia