A fatal plane crash near Ottawa’s airport in July 2025 was likely caused by improper application of engine sealant during maintenance, according to a newly released report from the Transportation Safety Board of Canada (TSB).
The Grumman AA-5A aircraft was carrying three people when it went down in a wooded area along Riverside Drive near Hunt Club Road on July 31, 2025. The pilot had attempted an emergency landing after reporting engine trouble but was unable to reach the runway. The pilot died, while both passengers sustained non-life-threatening injuries.
Investigators found that the engine’s No. 3 connecting rod had failed, damaging the camshaft and contributing to the loss of engine power. Other evidence included a bent rod, a fractured camshaft and metal debris inside the oil filter. The engine had last undergone maintenance on July 7, less than a month before the crash.
The TSB determined that Loctite-515 sealant had been applied incorrectly in several areas of the engine. The improper application likely reduced the clamping force between the engine’s crankcase sections, allowing unwanted movement and contributing to abnormal operation of the third cylinder before the engine failed.
Following the investigation, Transport Canada issued a civil aviation safety alert on July 16, 2026, warning those who own, operate or maintain Lycoming opposed-cylinder engines about the risks associated with incorrect sealant application during assembly.
The TSB also stressed the importance of following manufacturers’ maintenance procedures and service instructions, advising aircraft maintenance engineers to seek guidance from manufacturers whenever procedures are unclear or unfamiliar.