A months-long investigation by the Nepali government into the deadly plane crash at an international airport in Kathmandu, has pointed to the fault of a pilot. A leaked draft of the investigation report revealed that the pilot exhibited erratic behavior: from weeping to chain-smoking in the cockpit during the flight while also constantly arguing with his female co-pilot. It also suggested that the pilot lied to air traffic controllers about carrying out the proper procedures for landing, he seemed disoriented and had lost sight of the runway before the plane crashed at the airport.

On March 12, 2018, Flight BS211 of the US-Bangla Airlines took off from the capital of Bangladesh, Dhaka, and was headed for the Nepal capital Kathmandu. On landing, the aircraft, a Bombardier Dash 8 Q400, clipped the fence of the Kathmandu’s Tribhuvan International Airport (KTM) and crashed, bursting into flames. Out of the 71 people on board, 51 were killed. Both the pilot and the first officer also died in the crash. The accident was declared as the Himalayan nation’s worst aviation disaster in 26 years.

Different reviews of the yet-to-be-published final report tell somewhat varying circumstances of what took place in the cockpit before the plane’s deadly crash. According to Reuters, a draft of the investigation report compiled by the Nepali government-appointed panel, states that the captain, a former Bangladesh air force pilot, Abid Sultan, had been “extremely upset and hurt” by remarks made by “a female colleague” who questioned his reputation as an instructor for the airline.

The report describes the captain as being “very much under stress”, having several “emotional breakdowns” during the flight as well as “continuously smoking in the cockpit”, despite the first officer’s efforts to console him. “The captain was ‘crying and sneezing’ on several occasions during the flight,” the draft reportedly states, citing the recorded conversation between the cockpit and the air traffic controllers.

The investigation report has also been accessed by the Nepali daily Kathmandu Post. According to India Today, which cites the Kathmandu Post, the report clearly suggests that the captain “was under immense mental stress and anxiety” while flying and that his erratic behavior “should have raised immediate red flags” inflight.

"He seemed to be fatigued and tired due to lack of sleep," the Kathmandu Post quoted the investigators as saying from their analysis of the cockpit voice recorder. "He was crying on several occasions."

The voice recorder also captured the conversation between the captain and his co-pilot. At one point, he was heard saying, "I don't f---ing care about the safe flight, you f--- your duty." Apparently, as the Kathmandu Post revealed, the pilot was shouting at his female colleague with whom he had a dispute throughout the flight.

According to India Today, not only was the captain chain-smoking during the flight, investigators have also uncovered that he lit a cigarette just three minutes before starting the plane's descent. The pilot reportedly also admitted he made a mistake to his co-pilot when the plane was starting to land.

He then reportedly lied to the air traffic controllers about having locked down the plane's landing gears six minutes before making the final descent. Investigators reportedly found that when the co-pilot conducted a final landing check, she found that the gear was not down.

According to Channel News Asia, that also covered the story from the leaked report, the captain's constant monologue led to the "total disorientation" of the co-pilot, Prithula Rashid, who  apparently was flying the plane when it crashed. She had only recently qualified and had never previously landed at Kathmandu airport.

Reuters has a different take on the plane’s approach to land, stating simply that the captain “failed to follow instructions” from the air traffic controllers to land from a southern approach and took a more difficult northern approach to the single runway. He was unable to align the plane before landing. Nepal's only international airport lies in a narrow bowl-shaped valley surrounded by hills, with the Himalayas to the north. Landing here is considered very challenging.

Earlier this year, Reuters covered the initial investigation into the deadly crash, citing Kathmandu airport general manager, Kumar Chettri, who, at the time, suspected that wrong signals from the Kathmandu air traffic controllers might have led to the crash. „A three-minute conversation between the pilot and the air traffic control before the landing indicated that they sent a wrong signal to the pilot,” Chettri was quoted as saying.

Transmissions by the Kathmandu tower controller reportedly indicated that, despite being cleared to land on runway 02 where most international flights are directed to, the flight began deviating from its course. The captain and the tower discussed which runway the plane was aiming for. At one point, the controller told the co-pilot she was heading toward runway 20, although the plane had already been cleared for runway 02. Later, the captain took over the conversation and confirmed to land on runway 02. Eventually, the plane made an attempt to land on the runway it was originally meant to use.

An official of the investigation commission has told Reuters that the draft of the report had been “illegally leaked” on August 27, 2018, and that the final report would take some time to be published. Perhaps then we will have a clear view of what transpired in the cockpit before the plane’s fatal crash.

The US-Bangla Airlines is a privately owned airline of the US-Bangla Group, a Bangladeshi business conglomerate. It was founded in 2013 as joint venture between the U.S. and Bangladesh.