What happened
On 2/21/2019, an Airbus H125 (AS350B3) helicopter, registration VT-HDX, was conducting non-scheduled relief operations in the Uttarkashi district of Uttarakhand. The aircraft, operated by Heritage Aviation Pvt Ltd, was tasked with transporting essential supplies to flood-affected areas following heavy natural calamities.
After successfully delivering relief materials at Mori, the crew proceeded to a temporary helipad in Moldi village. This landing site had been hastily prepared that morning by local residents and authorities by leveling a patch of paddy crop. Following the offloading of supplies, the pilot initiated a takeoff. Due to the presence of a transformer pole and nearby houses, the pilot planned a departure toward the west, necessitating a 180-degree turn after gaining altitude.
During the climb and subsequent turn, the helicopter's main rotor blades struck trolley cables used by local villagers to transport apples across the valley. The impact with the North-South running cables caused the aircraft to lose control and be thrown toward a hillside. The helicopter struck a hill, caught fire, and rolled down the slope, resulting in the fatal deaths of all three occupants.
The investigation
AAIB India's investigation examined the wreckage, the temporary landing site, and the operational procedures used during the relief mission. Investigators found that the Moldi helipad did not meet the safety requirements established by the DGCA for temporary landing areas.
Technical analysis of the wreckage revealed that the main rotor blades had been damaged by the cables, with visible rubbing marks on the leading edges. The investigation also looked into the organizational framework of the relief operations, noting that the mission was coordinated via verbal instructions and email from local authorities rather than formal, standardized protocols. Furthermore, the investigation scrutinized the pilot's pre-flight actions and the operator's risk management processes.
Findings
- The primary cause of the accident was the impact with unmarked trolley cables spanning the valley.
- The temporary helipad at Moldi was inadequate, consisting only of a small, leveled area of crop with no formal safety infrastructure.
- The cables used for local commerce lacked any identifying markers, such as flags or balls, making them nearly invisible to the crew during flight.
- The pilot, despite significant experience in mountain flying, failed to perform a reconnaissance of the area or a survey of the flight path prior to takeoff.
- A lack of coordination existed between local authorities, the operator, and the DGCA, leading to a situation where mission accomplishment was prioritized over flight safety.
- The operator had not conducted a formal risk analysis or mitigation strategy for these specific relief sorties due to the perceived urgency of the flood situation.
Safety action
- It is recommended that the DGCA convert existing operational circulars into binding regulations to ensure all stakeholders adhere to safety standards.
- The 'Hill Check Performa' should be amended to mandate both high and low-level reconnaissance procedures.
- Authorities responsible for maintaining temporary helipads should be required to provide standardized safety information to operators before flight operations commence.