What happened
On October 10, 2022, a Piper PA-34-220T, registration HK2946, was operating an air ambulance mission from Guaymaral Flaminio Suárez Camacho Airport (SKGY) to La Primavera (SKIM). During the initial climb, while flying over the Tominé reservoir, the crew noticed abnormal indications on the right engine, including a drop in power, rising oil temperature, and decreasing oil pressure.
The crew requested a return to Guaymaral but did not declare an emergency, as they maintained control of the aircraft. During the final approach to runway 29, the number two engine failed completely. The resulting hard landing caused the right main gear tire to burst, though the aircraft remained on the runway near taxiway B. All 4 occupants—the pilot, co-pilot, a doctor, and a nurse—were uninjured.
The investigation
The GRIAA investigation focused on the mechanical failure of the Continental LTSIO-316-EB engine. Investigators examined the engine components and found that the oil filler cap was missing or improperly secured. This allowed oil to escape the system as engine pressure increased during flight.
As the oil level depleted, the lack of lubrication caused accelerated wear on internal components. The investigation established that the mechanical friction eventually led to the fracture of the number one connecting rod cap, resulting in a catastrophic failure of the power crankcase and total engine shutdown just as the aircraft was about to touch down.
Findings
- The primary cause was the progressive loss of the engine No. 2 lubrication system, leading to catastrophic mechanical wear and total engine failure.
- The oil filler cap was left loose or improperly closed during the engine oil replenishment or verification process.
- The crew failed to properly secure or shut down the number two engine despite observing clear indications of oil pressure loss and rising temperatures.
- The aircraft was airworthy and all maintenance documentation was up to date at the time of the incident.