Uncontained Engine Failure During Under-Sling Load Operation in Sudan (ZS-RTR)

Incident Overview and Aircraft Details On 24 January 2007, a Bell 206 L4 (Long Ranger) helicopter, registration ZS-RTR, was involved in an incident in Sudan. The aircraft was operating under a private operation. The pilot-in-command held a commercial licence and had a total of 6,087.1 flying hours, including 82.7 hours on type. The last mandatory periodic inspection was completed on 5 January 2007 at 4,994.4 airframe hours, with 90.0 hours flown since certification. ## Operational Context and Sequence of Events At approximately 1000Z, the pilot landed at a refuelling camp in Sudan to uplift fuel, bringing the total to 450 lbs (67 US gallons). The helicopter was then rehooked to an under-sling load of approximately 400 kg (880 lbs) of cabling, secured in a net with a medium-length strop. During take-off into a 10-knot wind, the pilot applied 80% torque, reducing to 70% at 40 knots indicated airspeed. The turbine outlet temperature was 711°C. At 60 knots, power was reduced to 60% torque, with all temperatures and pressures within normal limits. Approximately five minutes after take-off, the pilot heard a bang followed by a slight jerk and yaw, accompanied by a main rotor low RPM warning horn. The pilot released the under-sling load and executed an autorotation landing. At the time, the helicopter was approximately 300 feet above trees. The pilot turned toward an open field and landed directly into the wind. The helicopter touched down on the aft section of the skids first, with no forward speed, and the main rotor blades contacted the tips of the vertical stabilisers. The pilot completed normal shut-down procedures and applied the rotor brake. ## Damage and Injuries The pilot sustained no injuries. Damage to the helicopter was limited to the engine, engine cowling, and vertical stabilisers. A visual inspection indicated the engine had suffered an uncontained engine failure. The incident site was located on an open field approximately 5.4 nautical miles from a base camp in Sudan, with GPS coordinates N 08° 43.832' E 029° 51.480'. Weather conditions were fine, with a temperature of 37°C and a northerly surface wind of 10 knots.