Final Report on Mangalore Air Crash by Court of Inquiry

With Analysis by expert Simon Hradecky 
Courtesy: Aviation Web Portal

Apr 26: The Court of Inquiry (CoI) appointed to conduct the investigation into the crash by India's Ministry of Civil Aviation released their final report concluding:

Direct Causes

The Court of Inquiry determines that the cause of this accident was Captain’s failure to discontinue the ‘unstabilised 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 EGPWS.

Contributing Factors to the Accident

- In spite of availability of adequate rest period prior to the flight, the Captain was in prolonged sleep during flight, which could have led to sleep inertia. As a result of relatively short period of time between his awakening and the approach, it possibly led to impaired judgment. This aspect might have got accentuated while flying in the Window of Circadian Low (WOCL).

- In the absence of Mangalore Area Control Radar (MSSR), due to unserviceability, the aircraft was given descent at a shorter distance on DME as compared to the normal. However, the flight crew did not plan the descent profile properly, resulting in remaining high on approach.

- Probably in view of ambiguity in various instructions empowering the ‘copilot’ to initiate a ‘go around’, the First Officer gave repeated calls to this effect, but did not take over the controls to actually discontinue the ill-fated approach.

The captain (55, Serbian, ATPL, 10,215 hours as pilot in command, 2,844 hours on type) was described by collegues as a friendly person and ready to help the first officers with professional information. He was "assertive" and tended to indicate he was always right.

The first officer (40, Indian, ATPL, 3,620 hours total flying experience, 3,319 on type) was known as a man of few words and meticulous in his adherence to standard operating procedures. He had filed a complaint about another of the foreign captains, the company had therefore instructed rostering personnel to not pair the two before counseling had taken place (which did not occur before the crash).

Air India Express had mandated that due to the table top runway takeoffs and landings in Mangalore had to be flown by the captain.

The crew had performed the outbound flight IX-811 to Dubai and was to conduct flight IX-812 back to Mangalore. Ground personnel in Dubai reported that both crew appeared normal and healthy. They had left the aircraft and gone to the terminal building and the duty free shop during their 82 minutes turn over in Dubai. The crew did perform all pre-departure checks according to observations by ground personnel. The flight was to depart at 01:15 local Dubai time (21:15Z), which is 02:45 local Mangalore time and was estimated to arrive at 06:30 local Mangalore time (01:00Z).

Data off the flight data recorder and ATC recordings show the departure, climb and cruise of the aircraft were uneventful.

The cockpit voice recorder featured a capacity of 125 minutes. During the first 100 minutes of the recording there was no communication between the pilots however, all radio communication was done by the first officer. The captain's microphone occasionally recorded sounds consistent with deep breathing and mild snoring, at the later stages sounds of clearing the throat and coughing.

The first officer reported to Mangalore Area Control Center while overflying waypoint IGAMA at FL370 and requested radar identification at which time he was told that Mangalore's radar was out of service (starting May 20th 2010). About 5 minutes later, about 130nm before Mangalore, the first officer requested the type of approach to expect, was told to expect the ILS DME Arc approach to runway 24, and requested descent. ATC denied the descent however due to procedural control available only and instructed IX-812 to report at 80 DME on radial 287 of Mangalore's VOR MML.

About 9 minutes after reporting over IGAMA - and about 25 minutes before the overrun of the runway - the first verbal communication ("What?") by the captain was captured by the captain's microphone.

About 13 minutes after overflying IGAMA the first officer reported 80 DME on radial 287 and was cleared to 7000 feet, the descent commenced at 77nm from Mangalore VOR.

While the aircraft descended through FL295 an incomplete approach briefing was carried out, no standard approach briefing was conducted. At some stage during the descent, the actual time not mentioned in the report, the speed brake handle was placed in the flight detent and speed brakes deployed accordingly.

About 25nm before Mangalore the airplane was descending through FL184, still substantially above the descent profile, when the air traffic controller cleared the aircraft to 2900 feet.

The aircraft was subsequently handed to Mangalore Tower, who requested the crew to report once established on the 10 DME Arc. At about that time yawning was recorded by the first officer's microphone.

After the crew reported established on the Arc ATC requested to report when established on the ILS. At that time it is obvious the captain realised the airplane was too high on the approach. He had the gear lowered while descending through 8500 feet, speed brakes were still extended.

The aircraft continued to be high, intercepted the localizer beam and captured the false glideslope beam at double the correct approach angle (6 instead of 3 degrees descent). There was no cross check between actual altitudes/heights with the descent profile provided in the approach chart conducted by the crew.

Flaps were extended to 40 degrees, speed brakes were still extended.

On final approach, about 2.5nm from touch down, the radar altimeter went through 2500 feet, the first officer reacted to the aural message with "It is too high" and "runway straight down", the captain responded "Oh my God". The captain disconnected the autopilot and increased the rate of descent reaching about 4000 feet per minute sinkrate. The first officer asked "Go Around?", to which the captain responded "wrong loc ... localizer ... glide path". The CoI analysed that this was indicative of the captain recognizing the error and not being incapacitated due to his subsequent actions to correct the error. The speed brakes were stowed and armed.

The first officer called a second "Go Around! Unstabilized!", however the first officer did not take any further action to initiate a go-around, although company procedures required the first officer to take control after a second call to go around not complied with by the captain.

The captain further increased the rate of descent, the speed brakes were extended again until 20 seconds before touch down.

Numerous EGPWS aural warnings ("Sink Rate!" "Pull Up!") were issued in this phase of the approach.

The airplane crossed the runway threshold at 200 feet AGL at a speed of 160 KIAS instead of the target 50 feet AGL at 144 KIAS and touched down about 4500 feet down the runway, bounced and touched down a second time 5200 feet down the runway with just 2800 feet of paved surface remaining. Soon after touchdown the captain selected reverse thrust, autobrakes set to level 2 operated. About 6 seconds after the brakes began operating and after the reversers were selected the captain announced "Go Around" - against Boeing standard operating procedures not permitting go-arounds after selecting reverse thrust -, the brakes pressure decreased, the thrust reversers returned to their stowed position, both thrust levers were moved fully forward, the speed brakes retracted and remained retracted, the engines accelerated to 77.5/87.5% N1. The airplane departed the paved surface, the right wing impacted the localizer antenna, the aircraft went through the airport perimeter fence, fell down a gorge, broke up in three major parts and burst into flames. No distress call was received at any time. All but 8 passengers aboard perished.

The survivors, while getting up from their seats, heard and saw a number of other passengers unbuckle their seat belts, but they could not move due to the rapid spread of fire. All survivors escaped through cracks of the fuselage. 7 survivors received serious injuries, one escaped with minor injuries.

Boeing later determined that if the crew had applied maximum manual braking after second touch down, the airplane would have stopped 7600 feet past the runway threshold meaning the aircraft would have stopped within the paved surface of the runway (8033 feet long).