What happened
The incident occurred while a private pilot applicant was undergoing her certification checkride. During the flight, the aircraft's engine suddenly lost oil pressure. Recognizing the critical nature of the mechanical failure, the check airman assumed control of the aircraft. The crew identified a cornfield as the most suitable available landing area and executed a forced landing there.
The investigation
Post-accident examination of the aircraft revealed that the engine oil line had ruptured. Maintenance records indicated that the affected oil line had accumulated 1,949 hours of operation since its installation or last replacement.
Findings
A review of the Piper Service Manual showed a specific recommendation to replace oil lines every 1,000 hours. The failure occurred because the component had exceeded this recommended service interval by nearly double. The rupture was directly linked to the excessive time on the oil line and the resulting mechanical fatigue.