What happened
On May 3, 2012, an MI-8MTV helicopter, registration HK-4160, was operating a scheduled air taxi mission in the Putumayo Department of Colombia. After completing several legs of its flight plan, the aircraft landed at the Villa Garzón Aerodrome to pick up a passenger arriving on a commercial flight.
Upon arrival at the apron, the crew was notified by ground personnel that an incoming ATR 42 aircraft was approaching the ramp. Due to the presence of another helicopter (a Bell 206) and the incoming aircraft, space on the apron was limited. Following suggestions from ground staff, the pilot attempted several maneuvers to reposition the MI-8MTV to the southern side of the platform. During a left-hand turn while taxiing toward the western side of the apron, the main rotor blades struck a concrete utility pole located on the right side of the aircraft. The impact caused the blades to deflect downward, resulting in a fracture of the tail boom at the level of the horizontal stabilizer and significant damage to the tail rotor. There were no injuries to the four occupants on board.
The investigation
The GRIAA investigation focused on the sequence of ground maneuvers and the environmental conditions at the aerodrome. Investigators examined the aircraft's maintenance records, which showed the helicopter was in compliance with all regulations. The investigation also reviewed the company's recent organizational changes, specifically noting that the position of Load Master—a role previously responsible for ground coordination and obstacle clearance—had been eliminated by the operator 23 days prior to the incident without a formal reassignment of those specific respons as part of the crew's duties.
Findings
- The primary cause of the incident was the impact of the main rotor blades against a concrete utility pole during ground taxiing.
- The crew's situational awareness was compromised by a lack of visual contrast, as the grey rotor blades were difficult to distinguish against the grey concrete pole under overcast sky conditions.
- The lack of ground markings, such as taxi lines or edge markings, on the Villa Garzón apron made it difficult for the pilot to maintain adequate clearance from obstacles.
- The absence of a Load Master meant there was no dedicated crew member to coordinate ground movements or signal obstacles during the complex maneuvering required by the crowded apron.
- The crew's focus was heavily directed toward the task of parking the aircraft quickly to accommodate the incoming commercial flight, which led to a lapse in risk management regarding surrounding obstacles.