[Peetwo]

Number 13. from the list completed - 

Via Proof of ATSB delays and ICAO Annex 13 non-compliance??

13. AO-2021-032 (Short with a preliminary report attached and a safety advisory notice issued)

Via the Popinjay home page we get the now familiar media blurb, courtesy of this week's Director Transport Safety Kerri Hughes:

Acroduster in-flight break-up highlights importance of additional inspections



Key points

• Amateur-built Acroduster aircraft broke up in-flight when the left and right eye bolts and left roll brace connecting its upper wing failed due to fatigue cracking;
  
• A safety advisory has been issued by the ATSB, as well as the aircraft design owner, the US Federal Aviation Administration, and the Experimental Aircraft Association;
  
• [size=1]ATSB urges operators and maintainers of amateur-built aircraft to consider additional detailed inspections of parts of aircraft that are critical to safe flight.
  

The in-flight break-up of an amateur (kit) built Acroduster aircraft reinforces to operators and maintainers of these aircraft the importance of conducting additional detailed inspections of areas that are critical for flight.

On 18 August 2021, an amateur-built Stolp Acroduster II SA-750 biplane broke-up during a flight from Caboolture airfield, north of Brisbane. The pilot, who was the sole occupant, was fatally injured.

As noted in its preliminary report, the Australian Transport Safety Bureau’s technical examination determined two eye bolts, and the left roll brace, used to secure the aircraft’s upper wings, had failed due to fatigue cracking, triggering the break-up sequence.

Coinciding with the release of its preliminary report, the ATSB issued a Safety Advisory Notice (SAN) to owners and maintainers of Stolp Acroduster SA-700-750 aircraft, notifying them of the fatigue cracking issue.

“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 initial finding of fatigue cracking on the aircraft’s eye bolts was immediately shared, in August 2021, with the Civil Aviation Safety Authority, as well as the National Transportation Safety Board and Federal Aviation Administration in the United States (as the aircraft’s state of design), and the US-based Experimental Aircraft Association.

The aircraft design owner, Aircraft Spruce, was also notified.

The Experimental Aircraft Association subsequently released a notice on its website informing members of the accident, and a link to the ATSB’s preliminary report and SAN.

The Federal Aviation Administration issued a notice to more than 280,000 web subscribers informing them of the wing attachment point fatigue cracks, and also provided a link to the ATSB’s material.

Additionally, Aircraft Spruce issued a safety advisory notice to every purchaser of Starduster and Acroduster design plans since 2003.

“The ATSB welcomes these safety actions by authorities and the manufacturer in response to this accident,” Ms Hughes concluded.

Read the report: AO-2021-032: In-flight break-up, Stolp Acroduster II SA-750, VH-YEL, 16 km north-east of Caboolture airfield, Queensland, on 18 August 2021

Publication Date
28/04/2023

Not sure why the general statement..

“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.”

...could not have been issued when the preliminary report (47 days non-compliant with ICAO Annex 13) and the SAN were both published on 3 November 2021? And why it took a further 17 months and 25 days to complete a 'Short Investigation - ???' when it appears that the DIPs had all been informed and that there has been very little additional information or additional findings added since the prelim report was published?

"..The initial finding of fatigue cracking on the aircraft’s eye bolts was immediately shared, in August 2021, with the Civil Aviation Safety Authority, as well as the National Transportation Safety Board and Federal Aviation Administration in the United States (as the aircraft’s state of design), and the US-based Experimental Aircraft Association.

The aircraft design owner, Aircraft Spruce, was also notified.."   

The SAN:

Safety advisory notice

AO-2021-032-SAN-01:

The Australian Transport Safety Bureau advises all owners, operators and maintainers of Stolp Acroduster SA‑700/750 aircraft to consider the safety implications of the initial findings of this investigation regarding the fatigue cracking on forward cabane strut upper wing attachment eye bolts, and take action where considered appropriate to ensure that their aircraft remain airworthy.

Read more about this ATSB investigation at: AO-2021-032 link to preliminary report

Finally, how does this investigation meet the ATSB definition of a 'Short (desktop) Investigation'??

Short investigations

Short investigations provide a summary and analysis of commonly occurring transport safety accidents and incidents. Investigation activity includes sourcing imagery and documentation of any transport vehicle damage and/or accident site, conducting interviews with involved parties, and the collection of documents such as procedures and internal investigations by manufacturers and operators.

Short investigation reports include a description of the sequence of events, limited contextual factual information, a short analysis, and findings. Findings include safety factors (the events and conditions that increased the risk of incident or accident happening) but only examine the actions and conditions directly relating to the occurrence and any proactive safety actions taken.

MTF...P2