What happened
On August 10, 2017, a Piper PA-28 181, registration HK1894, was conducting a flight training mission near Zipaquirá, Colombia. The flight, operated by ADEVIA S.A., was intended to include a cross-country route to Ibagué and Girardot, but the itinerary was canceled due to cloud cover, leading the crew to perform visual flight rules (VFR) training maneuvers instead.
While returning to Guaymaral Airport to perform touch-and-go exercises, the aircraft suffered a sudden engine failure during a leg with a right wind component. The instructor pilot attempted emergency procedures to restart the engine but was unable to restore power. Given the low altitude, the instructor executed a controlled emergency landing in a field at the Club Pueblo Viejo golf course in Chía, Cundinamarca.
During the landing maneuver, the aircraft struck a tree with its right wing, causing the wing to detach from the root. The impact and subsequent ground slide caused significant damage to the fuselage, the nose gear, and the engine mount. Both the instructor and the student pilot evacuated the aircraft on their own and were uninjured.
The investigation
The GRIAA investigation focused on the engine's failure and the mechanical state of the fuel system. While the engine itself was found to be in good working order during post-accident ground tests, investigators identified a critical issue at the fuel inlet connection to the carburetor.
Technicians discovered a large amount of Teflon tape wrapped around the fuel hose threads. The investigation noted that the use of Teflon tape in fuel lines is explicitly prohibited by FAA maintenance standards (AC 43.13-1B) because it can lead to leaks or disconnections. Evidence of fuel dripping was found, indicating that the fuel hose had disconnected from the carburetor, cutting off the fuel supply and causing the engine to quit.
Findings
- The primary cause of the engine failure was the disconnection of the fuel inlet connection at the carburetor.
- The disconnection was facilitated by improper maintenance practices, specifically the use of non-aeronautical material (Teflon tape) on fuel connections, which is not recommended by the manufacturer.
- A contributing factor was the lack of adequate supervision during the installation of the fuel hose.
- The aircraft's right wing was lost due to the impact with a tree during the emergency descent.