The commission formed to investigate the causes of the accident of Nepal Airlines Corporation’s (NAC) de Havilland Canada DHC-6 Twin Otter 300 aircraft 9N-ABO in Jomsom blamed “human error” for the crash.
The plane had skidded off the runway and plunged 25 meters down the Kali Gandaki River while landing at Jomsom airport on May 16. There were 21 people, including three crew members, on board, but no human casualties were reported.
Unveiling the report on Tuesday, the commission’s member-secretary Buddhi Sagar Lamichhane said the pilot, Deependra Pradhan, did not follow the instructions of the control tower. “There was no technical problem in the airplane,” he said.
According to the commission, the pilot attempted to land the plane on Runway-06 despite the control room warned of high air wave speed. “The plane was suggested to land on Runway- 24 instead of Runway-06,” it said.
The report said the plane went out of control due to high-speed landing on the short runway. The crew members did not follow the standard threshold for landing, it said. The length of the Jomsom airport runway is 2,424 ft, and a plane has to start the landing process 300 ft ahead of the threshold. “But the plane launched the landing gear beyond the threshold limit,” it said.
After landing, the plane skidded off on the grass surface, 705 ft away from the runaway. But instead of leaving the plane in its state — as speed slows on a grass surface — the pilot increased the speed to take off again, according to senior aeronautical engineer Meghendra Kumar Shrestha, a member of the commission.
As per the report, the ground speed of the plane, which should not have exceeded 90 nautical miles during landing, was at 118 nautical miles, and there was lack of coordination between pilot Pradhan and the co-pilot Suresh KC during the landing.
To prevent similar mishaps due to human error, the report has suggested the authority to introduce an inspection mechanism to closely observe the activities of pilot and engineer. It has recommended reviewing airports that have shorter runways, which pose risk to regular flights. “There is a need for imparting training on pilots on the safety management system,” the report stated.
Source: http://www.ekantipur.com
