According to the report, under tremendous mental stress and anxiety the pilot made a series of erroneous decisions which led to the crash that killed 51 people
Nepalese investigators have blamed US-Bangla Airlines Captain Abid Sultan for March’s deadly plane crash at Kathmandu’s Tribhuvan International Airport—that killed 51 people.
Captain Abid was under tremendous mental stress and anxiety, the investigators said. They said the pilot appeared to have lied to the air traffic control during landing, reports the Kathmandu Post.
The investigators said a series of erroneous decisions by the pilot led to the accident.
The Bangladeshi airline had blamed the cr ash on air traffic control, but the airport claims the plane approached it from the wrong direction.
The Post, which claims to have obtained a copy of the government’s investigation, said the investigators found the pilot was behaving erratically.
Six minutes before landing, Captain Abid said the plane’s landing gears were down and locked. When co-pilot Prithula Rashid conducted a final check, the landing gears were not down. Minutes later, Flight BS211, which was carrying 67 passengers and four crew members, crashed and burst into flames.
Investigators said Captain Abid was chain-smoking during the hour-long flight from Dhaka to Kathmandu.
The former Bangladeshi Air Force pilot, who had clocked more than 5,500 flying hours, had not disclosed to the airlines that he was a smoker. This led investigators to conclude that he was undergoing severe stress inside the cockpit.
“When we analysed the conversation on the Cockpit Voice Recorder, it was clear to us that the captain was harbouring severe mental stress. He also seemed to be fatigued and tired due to lack of sleep,” investigators wrote. “He was crying on several occasions.”
After analyzing nearly an hour-long conversation between the captain and his co-pilot in the cockpit, the investigators concluded that the captain’s mood was tense throughout the flight and he lacked situational awareness.
“I don’t f---ing care about [a] safe flight, you f--- your duty,” he said at one point inside the cockpit, according to the report. It was not clear whom the pilot was directing the statement at, as the co-pilot was the only crew member present inside the cockpit during the flight.
The report also shows the pilot made multiple abusive statements towards a female colleague who had questioned his reputation as an instructor, and their relationship was a major topic of discussion throughout the flight. Records show that Prithula was a passive listener to Abid’s story throughout the flight.
“A cockpit is a place where personal conversations between colleagues are strictly prohibited when the aircraft is preparing to land or take off,” said Captain Shrawan Rijal of Nepal Airlines. “It’s a strictly enforced cockpit rule, which instructs pilots to focus entirely on the aircraft’s operations.”
The Sterile Cockpit Rule under the US Federal Aviation Administration regulation requires aircraft pilots to refrain from non-essential activities in the cockpit during critical phases of flight, normally below 10,000 feet.
The rule was imposed in 1981, following a review of a series of accidents that were caused by flight crews—who were distracted from their flying duties by engaging in non-essential conversations and activities during the flight.
According to details from the audio recorder, the pilot broke down at one point and said that he was “very upset and hurt by the behaviour of the female colleague” and that “she was the only reason he was leaving the company.”
The captain had expressed his desire to resign a day before the accident, the report says, although he had not submitted any written documents. He said he wished to continue on the job for three more months to complete training the co-pilots.
Abid joined US-Bangla in 2015. Prior to flying commercial flights, he had served in the Bangladesh Air Force. He had a history of depression, according to reports.
During his time in the Air Force, back in 1993, he was removed from active duty after a psychiatric assessment but was re-evaluated by a psychiatrist in January 9, 2002, and was declared fit to fly.
The report said Abid’s detailed medical history was not reviewed by US-Bangla Airlines when he was hired.
However, the report clarifies that the pilot did not exhibit any recurring mental issues during the medical examinations from 2002 to 2018.
“None of the medical reports that the committee reviewed from 2012 to 2017 mentioned any symptoms of depression,” the report said, adding that during his routine medical evaluations, he was declared fit—and free from any symptoms of depression.
The Civil Aviation Authority of Bangladesh conducts an annual medical evaluation of all of the country’s pilots. The airline staff can also visit any medical consultants on their own for any health issues.
A senior aviation expert told the Post that many pilots refuse to seek treatment for mental health issues because they fear the medical assessment will have a negative impact on their career.
“Broken relationships, personality disorders, work stress, alcohol and drug problems all spell disaster,” the expert, declined to be named because of his proximity to the investigation, said[J1]. “And they try to manage their depression themselves, without proper attention and treatment.”
“Those who do not seek timely help might see a recurrence of manifestations brought upon by their depression,” said Dr Khagendra Bahadur Shrestha, chief medical assessor of the Civil Aviation Authority of Nepal.
Aviation officials are expected to make a summary of the report public at the end of August.
Abid’s medical records also indicated inconsistent and unreliable responses about his smoking habit. In his self-declaration form from 2012 to 2014, he wrote that he had never smoked. In 2015, Sultan said he used to smoke but had quit in 2010. Then in his most recent medical evaluations in 2016 and 2017, he mentioned that he had never smoked.
Md Kamrul Islam, general manager (marketing support and public relations) of US-Bangla Airlines said they were waiting for the investigation report that the International Civil Aviation Organization, Civil Aviation Authority of Bangladesh (CAAB), and Nepal will provide based on the findings of cockpit.
He ruled out possibility of the report’s publication before November or December.
“We cannot know what actually happened during the crash without data from cockpit,” he said, before questioning reporting on a matter under investigation.
He also questioned the authenticity of the reports as the investigation committee is yet to publish the report.
How the crash unfolded
Flight BS211 left Dhaka airport at 12:30pm. About an hour later, the flight crew began preparations to land at Tribhuvan International Airport. At 1:50pm, the plane started its descent and the controls were handed over to Kathmandu airport’s air traffic control room, which directed the flight to descend to 13,500ft and cleared the aircraft to hold over a point named “Guras.”
At 2pm, the airport control tower instructed the flight to reduce its speed and descend to 12,500ft. The control tower cleared BS211 to approach runway 02 from the Koteshwor side.
When the crew did not follow the control tower's instructions, the approach controller at TIA asked the pilots why they were not holding over Guras. At this time, based on the cockpit voice recordings, Captain Abid responded: “Holding will not be required in this case."
According to the report, Abid then lit a cigarette, when the aircraft had just under three minutes to start its initial approach. This, the report says, demonstrated complacency and gross negligence of procedural discipline on the pilot’s part.
At this time, the aircraft had lost its use of the plane’s auto-flight guidance system control. And strong westerly winds, blowing at an average of 28 knots, pushed the aircraft to the east.
The tower informed the crew that they were cleared to land via the 02 side of the runway, but instead the aircraft seemed to be headed for 20 (on the Boudha side). The report said that at this stage, there was a complete loss of situational awareness on the part of the flight crew.
That is when another supervisor controller from the airport tower took over the microphone and cleared the flight to land via 20, assuming that it was the crew’s intention to land from the Boudha side.
The aircraft was struggling to locate the runway and continued flying northeast. When the aircraft descended to around 175 ft above ground level, a ground proximity warning system alarm went off.
The tower immediately asked the flight crew about their intention. Abid radioed his intention to land on 02. The air traffic control, while also handling the landing of another aircraft, a Buddha Air aircraft that was approaching from 02, cleared BS211 to land at 02. The information was relayed to BS211 to caution them that there was traffic ahead of them.
The aircraft then started to gain altitude. At this point, according to the report, the captain admitted to his co-pilot that he had made a mistake. Local pilots, who had been monitoring the development on the radar at the airport premises, raised concerns with the tower that the US-Bangla pilots appeared to be disoriented and lost. The tower then issued a landing clearance to the flight for either 02 or 20.
The CVR revealed that both pilots made several statements that reflected that they had completely lost their orientation of the runway, but the issue was not communicated to the ATC.
A few seconds later, the co-pilot reported sighting the runway. The captain, however, still appeared confused. Despite the runway in sight, the co-pilot made no callouts to discontinue the manoeuvre. Alarmed, the control tower hastily cancelled the landing clearance by saying “takeoff clearance cancelled.”
The ground proximity warning alarm sounded continuously in the cockpit while the aircraft flew as low as 45 feet, right over the domestic terminal building. Nepali airline officials at the time had expressed horror watching the plane fly so close to the tower – and had praised the pilot for skillfully avoiding hitting the tower and at least half a dozen fuelled planes parked at the parking bay.
Airport officials at the control tower had described the scene that afternoon, before the crash, as “something like a war film”—a complete suicidal attempt that nearly blew the tower.
The aircraft then finally touched down on the ground, with only its right landing gear hitting the runway, and skidded to crash through the airport’s periphery before coming to a halt on a nearby field.
The impact started a fire within six seconds because the aircraft had 2,800kg of fuel onboard.
The investigation commission said that because the crash had a low impact, passengers had a high chances of survival, but the rapidly spreading post-crash fire prevented passengers from escaping.
The accident was one of the deadliest aviation disasters involving an international carrier in Nepal since the Thai Airways and Pakistan International Airlines tragedies in 1992.
The investigation of Flight 211 concluded that the ATC’s handling of the flight was not a significant contributing factor to the crash. However, the report stated that some air traffic control management procedural lapses were noted on the part of the crew at the control tower.
As part of its key safety recommendations, the investigation is expected to ask the Civil Aviation Authority of Bangladesh to renew the licenses of permanently-grounded pilots for medical reasons, following thorough physical and psychological tests.