Final report on the INVESTIGATION OF RUNWAY EXCURSION ACCIDENT OF TURKISH AIRLINES TC-JOC said:
On March 4th 2015, Turkish Airlines Flight TK-726 experienced a runway excursion whilst landing at Tribhuvan International Airport (TIA) at 01:59 hrs. TK-726 was operating a scheduled passenger flight from Istanbul to Kathmandu with a total of 224 passengers with 11 crew members (2 Cockpit and 9 cabin crew). During landing the aircraft touched down towards the left edge of Runway 02 with the left hand main landing gear off the paved runway surface. The aircraft veered further to the left and came to a stop on the grass area between taxiway D and C. All passengers were evacuated safely after a brief period of time. There was no injury to passengers and crew. Fire did not occur at the time of accident.
The probable cause of this accident is the decision of the flight crew to continue approach and landing below the minima with inadequate visual reference and not to perform a missed approach in accordance to the published approach procedure.
The auto-pilots remained coupled to the aircraft until 14 ft AGL, when it was disconnected, a flare was attempted. The maximum vertical acceleration recorded on the flight data recorder was approximately 2.7 G. The aircraft pitch at touchdown was 1.8 degree nose up up which is lower than a normal flare attitude for other landings.
