What happened
On September 15, 2018, a Cessna 150K, registration CP-911, operated by a flight training center, was performing a local instructional flight at Jorge Wilstermann International Airport in Cochabamba. During the landing phase on runway 22, the instructor and student pilot experienced a failure of the right main landing gear. The aircraft attempted a go-around, but the crew notified air traffic control that the right wheel had detached.
The pilot declared an emergency due to limited fuel endurance and performed a low-altitude flight over the Laguna Alalay area to burn off excess fuel before returning for a second landing attempt. Upon touchdown, the nose gear collapsed and the aircraft tilted toward the right side. Because the right main gear was missing, the landing gear strut impacted the asphalt, causing the aircraft to veer off the runway axis. The aircraft eventually came to rest 82.58 meters from the runway centerline. Both the instructor and the student pilot evacuated the aircraft via their own means; no injuries were reported.
The investigation
The Bolivian DGAC investigation focused on the structural integrity of the landing gear and maintenance records. Technical analysis of the damaged components at a certified maintenance organization utilized non-destructive testing (NDT). The examination revealed that the spring assembly of the right main landing gear had suffered a fracture. Specifically, investigators found that the depth of pitting corrosion exceeded the limits established by the manufacturer.
While the aircraft's maintenance logs indicated it was being maintained by an approved organization and was considered airworthy, the investigation noted inaccuracies in the aircraft logbook regarding flight hours and fuel loading entries. Additionally, although the instructor was qualified for flight instruction, his medical certificate had expired 45 days prior to the accident.
Findings
- The primary cause of the accident was a fracture of the right main landing gear spring assembly due to weakening caused by corrosion.
- A contributing factor was the failure to comply with Supplemental Inspection No. 32-13-01, which specifies inspections designed to prevent corrosion in the landing gear.
- The instructor's medical certificate was invalid at the time of the occurrence.