What happened
On January 16, 2008, a Bell 212 helicopter, registration OB-1850, was performing a scheduled flight for a client at the KP-50 remote helipad in the La Convención district, Cusco. The flight was part of a series of operations involving the transport of personnel near a gas pipeline.
After picking up two passengers, bringing the total number of occupants to 11, the crew prepared for takeoff. The flight plan involved a vertical takeoff into a hover at two meters, followed by a lateral movement to clear nearby obstacles before climbing. During the climb, at an altitude of approximately 25 to 30 meters and a distance of about 90 meters from the takeoff point, the aircraft experienced a sudden descent. The rotor RPM (NR) dropped sharply from 100% to nearly 80%, triggering the low RPM warning siren.
Recognizing the loss of altitude and the proximity of trees, the pilot attempted an emergency landing in a nearby clearing. The aircraft struck three trees and crashed on its left side. While the crew and passengers were able to evacuate, the impact resulted in two fatalities and several serious injuries among the passengers and crew.
The investigation
The CIAA investigation focused on the aerodynamic performance of the aircraft and the environmental conditions at the remote site. Investigators examined the aircraft's maintenance records, weight and balance calculations, and the meteorological conditions at the time of the accident.
Key elements of the investigation included the lack of a windsock at the remote helipad, which prevented the crew from accurately assessing wind direction and intensity. Furthermore, the investigation noted that the aircraft was not equipped with a Flight Data Recorder (FDR), a requirement for helicopters of this maximum takeoff weight under Peruvian regulations. The absence of this data limited the investigators' ability to analyze the specific flight parameters leading up to the loss of rotor RPM.