Date:	Friday 7 April 2023
Time:	08:27 UTC
Type:	Piper PA-28-180 Cherokee Archer II
Owner/operator:	Cambourne Insurance Services Ltd
Registration:	G-AXSG
MSN:	28-5605
Year of manufacture:	1970
Engine model:	Lycoming O-360-A4A
Fatalities:	Fatalities: 0 / Occupants: 3
Aircraft damage:	Substantial
Category:	Accident
Location:	St Marys Airport, Hugh Town, Isle of Scilly -   United Kingdom
Phase:	Landing
Nature:	Private
Departure airport:	Henstridge Airport (EGHS)
Destination airport:	Isles Of Scilly-St. Mary's Airport (ISC/EGHE)
Investigating agency:	AAIB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
The Piper PA-28-180 (G-AXSG) experienced a runway excursion after landing due to the landing gear collapsing at St Mary’s Airport, Isles of Scilly.

On touchdown the left main landing gear collapsed. The cause of the collapse was failure of both upper torque link attachment lugs on the landing gear cylinder due to fatigue cracking. There is a known history of fatigue cracking on cast landing gear cylinders and a manufacturer’s Service Bulletin exists to regularly inspect the area around the attachment lugs. There is currently no Airworthiness Directive to mandate the Service Bulletin.

One Safety Recommendation is made to the CAA to ensure that the level of safety of cast main landing gear cylinders fitted to PA-28 and PA-32 aircraft is acceptable."

=Safety Recommendation 2024-001=
It is recommended that the Civil Aviation Authority undertakes an unsafe condition assessment, in accordance with the requirements of UK Regulation (EU) No 748/2012 Annex I Part 21.A.3, for the cast main landing gear cylinder cracking affecting PA-28 and PA-32 aircraft, and take appropriate action based on the outcome of the assessment.

=AAIB Conclusion=
The left main landing gear torque link attachment lugs failed due to fatigue cracking, causing the wheel assembly and oleo to come out of the landing gear cylinder on landing.

While a Servicing Bulletin exists to inspect the landing gear for fatigue cracking, the EASA Airworthiness Directive mandating the inspection was cancelled in 2020 due to the perceived low number of cast aluminium
cylinders in service and the level of risk of failure.

The Servicing Bulletin was carried out on G-AXSG, with the landing leg still fitted to the aircraft. It is possible that the fatigue cracks were present but were not detected using the dye penetrant inspection technique.

1. AAIB Final Report: https://assets.publishing.service.gov.uk/media/65ba505fc75d30000dca0fb4/Piper_PA-28-180_G-AXSG_03-24.pdf
2. G-AXSG history 1969-1973: https://cwsprduksumbraco.blob.core.windows.net/g-info/HistoricalLedger/G-AXSG-1.pdf
3. G-AXSG history 1973-1975: https://cwsprduksumbraco.blob.core.windows.net/g-info/HistoricalLedger/G-AXSG-2.pdf
4. https://www.flightradar24.com/data/aircraft/g-axsg
5. https://www.planelogger.com/Aircraft/Registration/G-AXSG/
6. https://en.wikipedia.org/wiki/St_Mary%27s_Airport,_Isles_of_Scilly#

G-AXSG was built in 1969 (first registered 17.11.69) and was with its 15th owner from new at the time of the above incident.

A report has been published into an accident involving a Piper PA-28-180 (G-AXSG) which experienced a runway excursion after landing due to the landing gear collapsing at St Mary’s Airport, Isles of Scilly on 7 April 2023 https://t.co/Snp1HO3xki #Aviation #Aviationsafety pic.twitter.com/zNwPgypQZp

— AAIB (@aaibgovuk) February 1, 2024

Date/time	Contributor	Updates
01-Feb-2024 15:31	Dr. John Smith	Added
01-Feb-2024 15:33	harro	Updated [Other fatalities, Departure airport, Embed code, Narrative, Accident report]