What happened
On November 24, 2015, a Dauphin AS 3SB N helicopter, registration VT-ELJ, was performing a scheduled flight from Mon to Meluri in Nagaland. While approaching the Meluri helipad, the pilot observed vehicles and crowds near the standard approach path and chose to deviate from standard operating procedures (SOP) to approach from a different bearing.
As the aircraft descended to approximately five feet above the ground, the rotor downwash disturbed loose mud and gravel, creating a massive dust cloud that completely obscured the pilot's vision. Disoriented by the loss of visual reference, the pilot attempted an aborted landing by initiating a go-around from a hover. During this maneuver, the main rotor blades and the nose of the aircraft struck a 30-foot-high hillock located about 45 meters from the helipad. The impact caused the helicopter to topple onto its left side, triggering a post-impact fire in the engine compartment and tail boom area. All six occupants—two crew members and four passengers—were rescued by local residents.
The investigation
AAIB India examined the flight history, aircraft maintenance records, and the environmental conditions at the landing site. The investigation confirmed that the Daupland AS 365 N was airworthy and that both pilots were properly qualified for the mission. Investigators analyzed the pilot's decision-making process, specifically the deviation from the established approach bearing and the decision to continue the approach despite seeing initial dust disturbances. The inquiry also looked into the management of the temporary helipad, noting that the site had not been watered to suppress dust, nor were firefighting or first aid services arranged by the local authorities prior to the flight.
Findings
- The primary cause of the accident was that the crew initiated a go-around without visual contact with the ground or nearby obstructions after being engulfed by a dust bowl.
- The pilot's decision to deviate from the SOP approach bearing (110/290) removed the safety margin that would have provided a clear path in the event of an aborted landing.
- The crew failed to execute a go-around when the first signs of dust were observed at 25–30 feet altitude.
- The helipad was in a poor condition, with unsuppressed dust and a lack of essential emergency services like firefighting equipment.
Safety action
- The DGCA is advised to ensure that helicopter operators verify all requirements for temporary helipad operations are met.
- Recommendations were made to include helipad reconnaissance (recce) in SOPs for infrequently used landing sites.
- Training programs should emphasize strict adherence to approach SOPs and improved decision-making during low-visibility transitions.