What happened
On 8 August 2022, a Diamond DA42 aircraft, registration 9M-HMY, was conducting circuit and landing exercises at Langkawi International Airport (WMKL) when it experienced a runway excursion. The flight, operated by HM Aerospace, was being conducted by an instructor and a student pilot.
During the final approach of a second circuit, the student pilot encountered a crosswind component from the right. While the pilot successfully managed the touchdown on the runway centerline using crabbing and rudder techniques, the aircraft suddenly began veering toward the right. Recognizing that the right wing was dropping, the instructor took control, immediately shut down both engines, and utilized the ailerons to prevent the propeller and engine from striking the ground. Despite applying left rudder and braking, the aircraft drifted off the runway and came to a rest on the grass verge of Runway 03. Both occupants were uninjured.
The investigation
AAIB Malaysia investigators examined the aircraft and the site of the incident. The investigation included a review of meteorological data, which confirmed a slight tailwind from the right during the approach. Maintenance records and a post-flight inspection of the aircraft were also analyzed.
Physical examination of the landing gear revealed that the right-hand main landing gear assembly had sustained significant damage. Specifically, the inspection identified that the right-hand main landing gear trailing arm had suffered a clean break. While the aircraft manufacturer (OEM) was requested to perform metallurgical testing to determine the exact reason for the fracture, the AAIB noted that no feedback had been received from the manufacturer at the time of the final report.
Findings
- The primary cause of the excursion was the failure of the right-hand main landing gear trailing arm.
- The aircraft experienced a sudden loss of directional control immediately following touchdown.
- The instructor's rapid intervention, including engine shutdown and aileron input, prevented further damage to the engines and propellers.