History of the Flight
On 26 April 2017, a Bell 206 B3 helicopter registered VT-DDA and operated by M/s Dhillon Aviation Pvt. Ltd. was conducting a series of sectors in Chhattisgarh carrying paramilitary personnel. The flight originated from Raipur at 0150 UTC, landed at Sukma at 0330 UTC, and then proceeded to Jagdalpur for refueling. The subsequent sectors were Jagdalpur–Sukma–Dharmapenta–Chintalnar–Chintagufa–Jagdalpur.
The pilot-in-command held a Commercial Pilot License (Helicopter) with Foreign Aircrew Temporary Authorisation (FATA) and had a total flying experience of 2197 hours 30 minutes, with 538 hours 50 minutes on the Bell 206. After completing earlier sectors, the helicopter departed Chintalnar with five persons on board (one pilot, one technician passenger, and three paramilitary personnel) for Chintagufa. The en route flight was uneventful.
The Chintagufa helipad is at an elevation of 764 feet. The pilot conducted a reconnaissance at approximately 600 feet AGL and awaited a smoke signal indicating the helipad was clear. After receiving the signal, the pilot descended via a circuit and made a shallow approach from the south/southwest.
Accident Sequence
During the approach, the pilot reported feeling convection in the atmosphere. While hovering over the helipad at about 3 feet above ground, the helicopter experienced an unexpected sudden left yaw. The pilot attempted to correct by applying right pedal, but the helicopter touched down and toppled to its right. The engine continued running and was switched off by the pilot.
Injuries and Damage
One passenger sustained minor injuries; no other occupants were injured. The helicopter was substantially damaged. Specific damage included separation of main rotor blades with hub from the mast, broken pitch links, disengaged mast, broken main gearbox linkages, broken tail rotor driveshaft, damaged right horizontal stabilizer, destroyed cockpit plexi, and damaged doors.
Pilot Information
The pilot was 32 years old, held a CPL(H) with FATA valid until 15 June 2017, and had a total flying experience of 2197 hours 30 minutes, with 538 hours 50 minutes on the Bell 206. The pilot had undergone a proficiency check on 20 November 2016 and a route check on 18 June 2016. The last medical examination was on 11 August 2016. The pilot had a rest period of 14 hours before the flight and had flown 3 hours 30 minutes in the preceding 24 hours.
Helicopter Information
The Bell 206 B3 is a single-engine helicopter certified for day VFR operations with a maximum takeoff weight of 1451.5 kg and a maximum operating altitude of 13500 feet density altitude. It was equipped with a Rolls-Royce 250-C20J turboshaft engine. The flight control system consists of push-pull control tubes and bell cranks actuated by conventional cyclic, collective, and directional controls. The accident occurred in daylight conditions. There was no fire.