Canada鈥檚 aviation safety agency is warning ultralight aircraft owners to make sure modifications are manufacturer-approved after investigating a fatal crash last year in northeastern British Columbia.

The Transportation Safety Board says the crash happened on June 25, 2023, when a two-seat Savannah aircraft crashed into Simpson Lake southwest of Chetwynd, B.C.

The only person aboard, the pilot and owner of the ultralight, was killed in the crash.

Investigators say an examination of the wreckage found the ultralight had an engine upgrade kit and some modifications to its wings, neither of which were approved by the manufacturer.

The TSB report says the changes were made by a previous owner, and purchase documents that were supposed to serve as a declaration of the plane鈥檚 airworthiness had 鈥渘o names, dates, or signatures of the previous or new owner.鈥�

The report concludes in its safety message to pilots that 鈥渙perating an aircraft that has been modified outside of the manufacturer鈥檚 specification may result in performance that does not match expectations.鈥�

Investigators also found that while there were possible wind gusts or up and downdraft circulations in the area at the time, there was no evidence of thunderstorm nearby.

鈥淩adar images showed little precipitation activity,鈥� the report says. 鈥淪atellite data revealed that the risk of icing in cloud was low and that even though smoke was present in the area, it would not have been significant enough to reduce visibility.鈥�

Investigators say it was the first time the pilot had flown to Simpson Lake, and he had about 40 of his total 400 flight hours in the plane that crashed.