Venezuelan Helicopter Emergency Landing Due to Collective Control Failure (YV357T)

Incident Overview and Flight Details On March 20, 2014, an AgustaWestland A109S helicopter, registered as YV357T, departed from the Ávila Helipad (SVHA) in Guarenas, Miranda State, bound for Arturo Michelena International Airport (SVVA) in Valencia, Carabobo State. The aircraft was carrying two crew members. During the cruise phase at an altitude of 4,200 feet, the pilot reported a loss of collective pitch control to the Maiquetía Area Control Center and executed an emergency landing in the La Bonanza sanitary landfill in Charallave, Miranda State, at coordinates 10°17’14” N / 66°53’30” W. Both crew members were unharmed, and the aircraft sustained minor damage. ## Aircraft and Crew Information The helicopter, manufactured in 2008 with serial number 22063, was powered by two Pratt & Whitney P&W 207c engines. The pilot in command was a 56-year-old male with a commercial helicopter pilot license and instructor qualifications, holding 9,654.8 total flight hours and 679.15 hours on the A109 model. The co-pilot was a 22-year-old male with a commercial helicopter pilot license and 600 total flight hours, including 420 hours on the A109S. The aircraft had 678.9 total flight hours and had undergone its last maintenance inspection on March 19, 2014. ## Investigation Findings and Probable Cause The investigation determined that the incident was caused by the incorrect installation of the lower shear link (part number 109-0134-10-105, serial number D22425) in the main rotor control plate. This error resulted in the fracture of the NAS6606D28 bolt due to over-stress, causing the shear link assembly to disconnect from the control plate and rendering the collective control system inoperative. A contributing factor was the lack of supervision, inspection, and certification of maintenance work orders, as well as the failure to comply with mandatory bulletins. No fire occurred, and the crew was able to evacuate the aircraft independently.