What happened
On April 27, 2012, at approximately 09:45 a.m., a Grumman G 164-A agricultural aircraft, registration HI 823, was performing its final spray pass of the day over a rice plantation in La Enea, Duarte Province, Dominican Republic. While flying at an altitude of approximately five feet above the crop, the pilot experienced a sudden loss of engine power.
Due to the extremely low altitude, the pilot was forced to perform an immediate emergency landing in a rice field near the Guamasaje River. The aircraft impacted the terrain, skidded approximately five to seven meters, and eventually came to rest in a tilted position with the engine and cockpit partially submerged in the river. The pilot, the sole occupant, escaped the wreckage uninjured.
The investigation
The CIAA investigation focused on the mechanical condition of the engine and the flight controls. Investigators examined the aircraft's maintenance records and inspected the engine compartment at the operator's hangar.
Upon inspection of the power control system, investigators discovered that the power control cable had severed at the engine firewall. The investigation revealed that the breakage was the result of progressive friction between the cable and its metallic sheath. Because the cable was positioned at an angle where it met the firewall, the friction gradually wore through the braided filaments. This degradation was not visible to maintenance technicians due to the protective metallic covering. Furthermore, the investigation noted that the aircraft's maintenance manual did not specify a service life or replacement interval for this specific control cable.
Findings
- The primary cause of the accident was the rupture of the engine power control cable due to friction.
- The breakage caused the engine to automatically drop to idle power due to the carburetor's spring-loaded safety mechanism.
- The aircraft sustained substantial damage, including the loss of the left main landing gear, dents to the vertical stabilizer and upper wing surfaces, and engine damage.
- The pilot's medical certificate had expired on January 31, 2012.
- There was no evidence of formal specialized training for this specific type of agricultural flight in the pilot's records, despite his extensive flight experience.
Safety action
- The CIAA recommended that the IDAC establish mandatory periodic inspections for power control cables on all agricultural aircraft, as current maintenance manuals do not define a useful life for these components.
- The CIAA recommended that the IDAC ensure all agricultural pilots undergo formal training through authorized schools and maintain valid medical certifications.