A draft report that was leaked following an investigation into an air crash at the Kathmandu airport in March has found that the captain of the plane was “under stress and emotionally disturbed”, AFP reported on Monday. Fifty-one people died when the US-Bangla Airlines plane from Dhaka crash-landed in Kathmandu on March 12.

Captain Abid Sultan was weeping and under severe stress after a co-worker had allegedly “questioned his reputation as a good instructor”, AFP said after accessing the investigation report. He was allegedly smoking continuously in the cockpit and talking “non-stop” to his co-pilot, Prithula Rashid.

“This mistrust and stress led him to continuously smoke in the cockpit and also suffer an emotional breakdown several times during the flight” and he “was crying and sneezing on several occasions”, according to the report.

Sultan was a former Bangladesh Air Force pilot and also a flying instructor with the airline. Rashid, however, had only recently qualified to be a co-pilot and had never landed in Kathmandu before. The Kathmandu airport is known to be one of the world’s most difficult airports to land in.

The aircraft also did not carry out necessary landing checks, did not reduce speed sufficiently, and made a last-minute change of direction as it approached the runway, AFP reported.

Twenty of the flight’s 71 passengers had survived the crash. The accident is believed to be Nepal’s worst aviation disaster since a Pakistan International Airlines aircraft crashed in 1992, killing 167 passengers.

Reports after the crash had said that airline and air traffic control authorities were pointing fingers at each other over what had caused the incident. A US-Bangla Airlines official had claimed the air traffic control had misled its pilot, but Tribhuvan International Airport said the captain had ignored their signals.

US-Bangla Airlines suspended all flights to Kathmandu following the crash.