Summit Air (Nepal) Flight 409

The aircraft involved by the crash was a Let L-410, built in 2014 for Summit Air (then operating as Goma Air), registration 9N-AKY. The aircraft was involved in a prior minor accident on 2 June 2015, where the flight from Jomsom landed in Pokhara with the nose gear retracted. All 18 passengers on board were safe, but the aircraft suffered damage to its nose.[2]

The Captain, aged 48, had over 9000 flight hours logged, and since joining the airline, had flown over 1900 hours on L-410 aircraft. He died shortly after being pulled from the wreckage. The co-pilot died at 21:30 local time in intensive care at Lukla Hospital. The cabin crew member survived the crash and was soon medically evacuated to Kathmandu for further treatment.[3]

At about 14:04 local time, the aircraft was on final approach to Runway 06 of Tenzing-Hillary Airport, on a routine flight from Kathmandu Airport, when it descended below the minimum safety altitude just off the runway and impacted with a tree and contacted ground three metres below the runway. It then slid over 200 meters down a ravine. CCTV footage released by the airport showed the aircraft dipping below the runway level and smoke rising from the wreckage. Witnesses stated that the weather conditions had been foggy, and that visibility was quite low. The airport does not possess any sort of navigational equipment, requiring pilots to land via visual approach.[4][1] The up-slope runway 06 is without any instrument approach guidance. At the time of the accident, local visibility was substantially reduced by ground fog.

After the accident, it was suspected that the probable cause of the accident was an aerodynamic stall brought on by low approach speed. Due to the abnormally short runway on Lukla, aircraft are required to approach the airport at very low speeds, making the aircraft extremely vulnerable to sudden downdrafts and strong winds that are known to occur in the mountains. Contributing factors might include poor visibility on final approach and the inexperience and lack of technology available to air traffic control.[5]

In December 2017, an investigation committee of the Civil Aviation Authority of Nepal submitted its final report on the accident and concluded that "Very low visibility" was the cause of the accident. As the aircraft was flying through dense fog for several minutes before the approach, it missed the runway of Lukla Airport. The report furthermore revealed that both air traffic control of Lukla Airport (who did not close the airport despite the foggy weather) and the crew of Flight 409, who are also suspected to have been stressed and fatigued, had violated standard operating procedures. Lastly, the committee suggested that a runway extension of Lukla Airport should be considered, which would make the airport, where several accidents have occurred in the past, safer.[6]

Contrary to common practices in aviation, Summit Air did not retire the flight number 409 and still operates the flight from Kathmandu to Lukla under this number.[7]

• Yeti Airlines Flight 103
• Buddha Air Flight 103
• 2012 Agni Air Dornier 228 crash