What happened
On November 13, 2010, a Fairchild SA 227-AC, registration N781C, operated by LC Busre S.A.C., was performing a scheduled flight to Andahuaylas, Peru. The aircraft had previously completed a flight to Huaraz, during which the pilot reported a directional control issue. Although maintenance personnel cleared the aircraft for flight, the pilot noted difficulties with ground steering during taxiing.
Upon landing at Andahuaylas Airport, the crew initially followed normal procedures. However, as the aircraft decelerated to approximately 40 knots, it began an intense, uncontrolled left turn. The crew attempted to correct the deviation using right-side braking, right-side reverse thrust, and differential engine power, but the aircraft continued to veer left at an angle of approximately 30 degrees. As the aircraft exited the runway and approached a 4-meter slope in the adjacent terrain, the pilot shut down the engines. This action eliminated the differential power necessary to counteract the turn, causing the aircraft to veer sharply and descend the slope.
The accident resulted in 5 fatalities and 14 injuries among the passengers, while the two crew members sustained minor injuries. The aircraft sustained major damage to the fuselage, engines, propellers, wings, and landing gear.
The investigation
The CIAA investigation examined the aircraft's maintenance history, flight data, and cockpit voice recordings. Investigators established that the Nose Wheel Steering (NWS) system was deferred under the Minimum Equipment List (MEL) as category "C." The investigation also reviewed the aircraft's recent maintenance logs, which showed that the aircraft had experienced directional control issues and brake system problems in the days leading up to the accident.
Flight data recorders confirmed that while engine performance and control inputs were within operational parameters, the aircraft began deviating from the centerline at 50 knots. The cockpit voice recorder revealed that while the pilot had briefed emergency procedures for a steering failure, the instructions provided during the descent were imprecise and proved ineffective during the actual emergency.
Findings
- The primary cause was the loss of directional control during landing due to multiple failures in the braking system, specifically a locked brake on the left main gear and a total failure of the right main gear brakes.
- The crew's decision to operate the flight with known brake issues prevented the necessary operational conditions required by the MEL for flying with deferred Nose Wheel Steering.
- The pilot's emergency briefing regarding steering failure procedures lacked the precision required to manage the event effectively.
- The operator had a high frequency of significant incidents, with 63 recorded in the ten months preceding the accident.