Investigators have determined that a faulty engine component caused a light aircraft to make an emergency crash landing on Mona Vale Golf Course last August.
The Australian Transport Safety Bureau released its findings on Thursday, revealing that a broken exhaust valve led to the dramatic incident on 17 August last year.
The Piper Cherokee aircraft was conducting a navigation training flight with a student pilot and instructor aboard when it experienced engine trouble around 2pm. The plane had departed from Shellharbour Airport and was approximately 1600 feet above the Northern Beaches when the problem occurred.
According to the ATSB report, the crew heard unusual sounds from the engine before experiencing a sharp decrease in revolutions per minute. The instructor had been monitoring potential emergency landing locations throughout the flight as standard practice.
ATSB Chief Commissioner Angus Mitchell explained in a statement that the instructor’s first choice was Long Reef Golf Course due to fewer obstacles. However, as the engine continued to fail over the following six minutes, Mona Vale Golf Course was identified as the safest available option.
During the final approach, the pilot needed to execute a right turn to avoid golf course buildings, as landing straight ahead was not viable. The manoeuvre resulted in the right wing dropping, and the aircraft landed heavily on a fairway, causing substantial damage to the plane.
Golfers on the course watched in astonishment as the incident unfolded that Sunday afternoon.
The student pilot sustained minor injuries, whilst the instructor was unharmed. Mr Mitchell credited the pilot’s quick thinking in identifying a suitable landing site with preventing a potentially worse outcome.
The investigation determined that the exhaust valve on the engine’s number three cylinder had separated from its stem, causing significant internal damage to the cylinder, piston and spark plugs.
Investigators were unable to establish the underlying cause of the valve failure. The report notes that engine manufacturer Textron Lycoming has issued maintenance recommendations aimed at reducing the likelihood of valve problems.
Mr Mitchell emphasised the incident demonstrated the critical importance of effective decision-making during aviation emergencies.
Published 22-January-2026
