History of the Flight
The aircraft was conducting an introduction to aerobatics flight with a student pilot. The flight instructor was the sole crew. The approach to Runway 24 was normal. Shortly after touchdown, the left landing gear leg separated at the bend at the top of the leg. The pilot applied aileron to keep the left wing up until airspeed reduced. The left wing then dropped, contacting the runway, and the aircraft veered left, coming to rest off the runway in grass. The propeller struck the ground. Both occupants were uninjured and exited without assistance.
Aircraft Information
G-TALX was a Bellanca (American Champion) Decathlon 8KCAB, a high-wing, two-seat tailwheel monoplane, powered by one Lycoming AEIO-320-E1B piston engine. It was manufactured in 1980. The aircraft was equipped with steel landing gear legs. The legs had been installed at 4,999 airframe hours in May 2018 following an unrelated landing gear attachment bolt failure during an engine ground run. At the time of the accident, total airframe hours were 5,612.
Maintenance Information
The most recent 100-hour/annual inspection was performed on 20 March 2025, 40 hours before the accident. The work pack included a check for corrosion on the landing gear, and no corrosion was reported. The manufacturer had issued Service Letter SL-449 in May 2018, recommending corrosion inspections every 45 days for aircraft operating in moderate or severe environments, applicable to Decathlon. However, this service letter was not mandatory under the Approved Maintenance Program. The corrosion severity map in FAA Advisory Circular 43-4B indicates Tatenhill Aerodrome lies in a moderate corrosion zone.
Landing Gear Leg Examination
The fractured left landing gear leg was examined by the AAIB. The fracture occurred near the fuselage attachment point. Corrosion was evident on the underside of the leg where paint had been lost. Under scanning electron microscopy, thumbnail-shaped features up to 1.66 mm deep showed characteristics of fatigue crack propagation. The remainder of the fracture surface exhibited overload failure features. No manufacturing defects were found.
Related Events
Two similar accidents involving Decathlon aircraft were identified: N5026B in Alaska (2012) and LN-LCU in Norway (2015). Both involved landing gear leg fractures. The NTSB investigation for N5026B found fatigue initiated from pits on the lower surface of the leg. The Norwegian report noted that latent weaknesses from steel fatigue cracks were not easily discovered during visual inspection.
Conclusion
The accident occurred because the left landing gear leg suffered an overload failure on touchdown due to fatigue crack propagation initiated by surface corrosion. The corrosion likely resulted from paint loss exposing the steel surface. The investigation could not determine whether the manufacturer’s service letter inspections would have detected the damage, but similar investigations noted that corrosion and fatigue cracks in this area are difficult to identify visually.