What happened
A Saab 340, registration TG-TAI, was operating a passenger flight from Cancun International Airport, Mexico, to Mundo Maya International Airport in Petén, Guatemala. During the approach to the destination, the crew attempted to deploy the landing gear. While the hydraulic actuator for the right gear extended, the assembly failed to reach its fully locked position.
As the aircraft prepared for landing, the crew communicated with air traffic control to verify the status of the landing gear and coordinate emergency services. The aircraft was carrying 14 passengers and a cabin crew member, along with the two pilots. Despite the mechanical irregularity, the occupants were able to evacuate the aircraft without any injuries.
The investigation
The investigation conducted by the Guatemalan Accident Investigation Unit focused on the mechanical integrity of the landing gear assembly. Investigators examined the aircraft's maintenance records, which were found to be up to date according to the required service intervals. The investigation also reviewed the flight parameters, including weight and balance, and the meteorological conditions, which were favorable for visual flight rules (VFR) with unlimited visibility.
Technical analysis of the landing gear mechanism revealed that the failure originated within the hydraulic actuator assembly. The investigation also looked into the maintenance practices of the approved maintenance organization responsible for the aircraft's upkeep.
Findings
The investigation established that the primary cause of the accident was the collapse of the right landing gear hydraulic actuator support due to the breakage of a mounting bolt.
When the pilot activated the electric selector in the cockpit, the hydraulic actuator began to extend. However, during this movement, the mounting bolts at the base of the actuator fractured. This structural failure prevented the landing gear assembly from extending completely, which in turn prevented the downlock mechanism from engaging to secure the main gear.
Safety action
Based on the findings, the following safety recommendations were issued:
- Maintenance organizations should perform detailed visual and manual inspections of installed components to check for loosened parts, missing safety pins, or shifted torque marks. Critical landing gear components should be specifically included in maintenance inspection checklists.
- All components installed following an overhaul must be certified for installation, ensuring they meet the specific standards and requirements set by the aircraft manufacturer.