Primary finding
Probable cause
A substantially damaged firewall that occurred during an unknown phase of flight for reasons that could not be determined.
Investigator assessment
Analysis narrative
During a preflight inspection, a flight instructor discovered that the airplane’s firewall was substantially damaged. The operator reported that the damage occurred during an unknown flight operation. The airplane's last maintenance inspection occurred about a month prior to the discovery, equating to about 52 flight hours. Numerous pilots flew the airplane during that duration, none of which reported an event that would result in damage to the airplane. A determination as to the cause of the accident could not be made.
Source record
Factual narrative
During a preflight inspection, a certified flight instructor discovered that the airplane’s firewall was substantially damaged. The operator reported that the damage occurred during an unknown flight operation. The airplane's last maintenance inspection occurred about a month prior to the discovery, equating to about 52 flight hours. Numerous pilots flew the airplane during that duration, none of which reported an event that would result in damage to the airplane. A determination as to the cause of the accident could not be made.