The Australian Transport Safety Bureau (ATSB) today issued a warning to all owners and pilots of experimental aircraft about the importance of inspections, following the fatal crash of an Acroduster biplane in August 2021.
VH-YEL was conducting aerobatics north of Caboolture when it crashed killing the pilot. ATSB investigators later found the top wing separated because of fatigue cracks in the eye bolts and roll brace.
“In this accident, the fatigue cracks formed in an area of the eye bolts that were obscured by the securing nuts and threads of the eye bolts,” ATSB Director Transport Safety Kerri Hughes said.
“This meant the cracks would not have likely been readily identifiable during standard maintenance inspections, without disassembling the attachment points.
“Owners and maintainers of experimental amateur-built aircraft should consider conducting additional detailed inspections that exceed the minimum standards, in areas of the aircraft that are critical to the safety of flight.”
The pilot of YEL departed Caboolture airport for a session of aerobatics around 0900 local time on 18 August 2021. Shortly after, the crew of a helicopter in the area saw red and white debris falling from the sky. They located the wreckage close to the mainland shore of Pumicestone Passage, inverted in tidal wetlands.
ATSB investigators found the centre section of the upper wing away from the main aircraft wreckage, and technical examination of the attachment points identified fatigue cracking on the eye bolts located in the upper wing forward position on the left and right cabane struts.
The initial finding was immediately shared with CASA, as well as the National Transportation Safety Board (NTSB), FAA, the Experimental Aircraft Association (EAA) and the aircraft design owner, Aircraft Spruce.
The EAA subsequently released a notice on its website informing members of the accident, and a link to the ATSB’s preliminary report and Safety Advisory Notice.
The full report is on the ATSB website.