This is what led to US-Bangla plane crash that killed 51 people last year

New Delhi, Jan 28: The investigation report compiled by Nepalese officials on US-Bangla airline Bombardier UBG-211 crash that occurred in March 2017 were made available on Monday that said the probable cause of the crash was due to the pilot, who had smoked inside the cockpit despite restrictions.

"The company has a policy of 'No Smoking' in all the flights, domestic as well as international. The PIC (pilot in command) was a smoker as per information received by the commission. The commission concluded from CVR (cockpit voice recorder) record that PIC smoked in the cockpit during this flight. However, the operation department and other authorities may not have been sure about this safety violation by the PIC during flight," the Accident Investigation Commission formed to probe the reasons behind the crash of the airline stated in a statement.

The reports clarified that only tobacco was used during the flight duration and ruled out the use of any other sort of banned assorted items consumed during the flight time.

The report also said the pilot had been released from the Bangladesh Air Force in 1993 due to depression and was only allowed to fly civilian planes from 2002 after a detailed medical evaluation.

Also, the pilot was under stress and emotionally disturbed and had lack of sleep in the preceding night.

The report also cited a lack of assertiveness from controllers at Kathmandu airport in monitoring the flight path and failing to issue clear instructions to carry out a standard missed-approach procedure.

The flight crew and the controllers also lacked a clear understanding of each other when they communicated about the landing runway, the report said.

As many as 51 people lost their lives when the aircraft crashed immediately after landing on Nepal's Tribhuwan International Airport (TIA). The reports were published laterafter the investigation commission submitted it to the Nepali Ministry of Culture, Tourism and Civil Aviation.

The post-mortem of the deceased, performed in the Department of Forensic Medicine in Kathmandu, revealed that the death of the passengers was a result of head injuries caused by the blunt force of the crash.