Accident Overview
On October 19, 1988, Vayudoot Flight VDT703, a Fokker F27 registered as VT-DMC, was operating a scheduled service from Silchar to Guwahati, India. The aircraft departed Silchar at approximately 0810 local time from runway 06. Weather at departure was reported as visibility 3 km with rain.
Timeline of Events
After takeoff, the flight reported an estimated time of passing Point Hotel at 0820 LT and an estimated arrival at Guwahati at 0850 LT. At 0823 LT, the flight reported over Point Hotel at flight level 105. The aircraft was then in contact with Guwahati control and was cleared to switch to Guwahati control tower.
At 0839 LT, the flight reported to ATC that they were passing through FL55 for 40 and would call over the VOR for an ILS letdown outbound. At 0846 LT, the aircraft commenced a procedure turn. At 0847 LT, the crew reported that they were not receiving the glide path. At 0848:15 LT, the aircraft reported turning inbound after completing the procedure turn. At 0848:45 LT, the aircraft reported passing the outer marker inbound. The aircraft lost contact with ATC at 0853:30 LT.
The aircraft was destroyed after impacting a hill and subsequently caught fire. The accident site was located more than 10 nautical miles from Guwahati Airport. All 34 persons on board, including three crew members, sustained fatal injuries.
Probable Cause
An error on the part of the pilot-in-command in obeying the localiser bar on the outbound leg when it is supposed to be disobeyed and which has resulted in disorientation of the pilot resultant effect of which is total non-adherence of the ILS let down procedure at Guwahati viz. failure to monitor the middle and outer locators, allowing the aircraft to descend below 2750 feet without intercepting the localiser and glide slope. The wrong clearance by ATC in asking the aircraft to report outer marker inbound when Captain-in-command reported non-availability of the Glide slope has misled the captain and as such has contributed to the accident. The possibility of sabotage or the aircraft outliving its age has been ruled out. The pilot failed to follow approved procedures, directives, instructions, etc.