What happened
On December 5, 2011, a Cessna 182 was performing a multi-leg flight originating in Macas, with stops in Taisha and Kankaime Sur. After departing Taisha with two passengers, the aircraft arrived at Kankaime Sur, landing on runway 05. The touchdown occurred 76 meters from the threshold, centered on the runway axis.
While taxiing, approximately 31 meters past the touchdown point, the nose landing gear encountered a soft area of the unpaved surface. The gear sank into the ground, causing it to buckle backward and fracture. This failure caused the aircraft to veer 15 degrees to the right, eventually settling on its nose. The aircraft continued to slide for an additional 70 meters before coming to a complete stop. There were no injuries to the pilot or the two passengers.
The investigation
The investigation focused on the runway conditions and maintenance records of the aircraft. Investigators found that while the aircraft was airworthy, there were significant discrepancies in the maintenance logs, specifically regarding how inspection items were recorded and errors in Airworthiness Directive (AD) compliance tracking.
Regarding the airfield, investigators noted that although it had not rained immediately prior to the accident, heavy rainfall in the preceding days had left the runway surface unstable. The investigation revealed that the middle section of the dirt runway contained a depression that prevented proper drainage, leading to the accumulation of water and mud. This created a subsurface area of soft ground that was not visible or assessable by the pilot during pre-landing reconnaissance.
Findings
- The primary cause of the accident was the presence of a soft terrain zone on the runway caused by water accumulation due to inadequate leveling and drainage.
- The nose gear failure resulted in secondary damage, including fractures to the landing gear, engine cowling deformation, propeller tip damage, and punctures to the horizontal stabilizer and elevator.
- Maintenance documentation for the aircraft contained errors in the application of inspection checklists and AD compliance records.
- There was a discrepancy in the recorded empty weight of the aircraft used by the operator for dispatch purposes.