What happened
The pilot was operating an aircraft when the engine began to exhibit signs of a runaway propeller, prompting an immediate shutdown of the powerplant. Following this mechanical failure, the pilot executed a forced landing on a nearby road. During the landing roll, the left wing tip struck a reflector post. Shortly thereafter, the right wing also made contact with a sign post, resulting in damage to both wings.
The investigation
An examination of the aircraft was conducted after the accident occurred. Investigators found that no oil was present within the engine compartment. Additionally, the oil drain plug was missing from its designated position. Records indicated that an engine overhaul and an annual inspection had been completed just 20 days prior to the incident. It was determined that the drain plug had not been safety wired as required by the manufacturer.
Findings
The primary mechanical issue involved the runaway propeller which necessitated the emergency shutdown. The absence of oil and the missing drain plug suggest a failure in maintenance procedures or inspection protocols, despite the recent overhaul. The aircraft sustained structural damage to the wings due to contact with stationary objects on the ground.
Safety message
Proper installation and safety wiring of critical components such as oil drain plugs are essential to prevent fluid loss and subsequent engine failure. Regular inspections must verify that all maintenance tasks, including those performed during overhauls, adhere strictly to manufacturer specifications.