What happened
On November 12, 2014, a Saab 340A operated by Sky Taxi was performing a repositioning flight to Wrocław following the completion of cargo operations. The crew, consisting of a commander, a co-pilot, and a mechanic, was executing a takeoff from EDSB. During the takeoff roll, once the aircraft reached a speed of approximately 70 knots, the crew observed a "CONFIG WARNING" on the Crew Alerting Panel (CWP).
In response to the alert, the commander initiated a rejected takeoff, applying the brakes gently to bring the aircraft to a safe stop. After notifying Air Traffic Control (ATC) of the aborted takeoff, the crew inspected the aircraft's takeoff configuration and determined it was otherwise correct. The investigation noted that while the elevator trim settings were within the permissible limits, they were positioned at the very edge of the green operating range.
The investigation
The investigation focused on the aircraft's trim settings and the pilot's actions during the takeoff roll. It was established that because the aircraft was departing without cargo, the pilot had pre-configured the trim to a position of approximately 1.3. During the takeoff roll, the commander increased the trim deflection further in an attempt to relieve pressure on the nose wheel. Although this increased deflection remained within the green band, it was close enough to the threshold of the configuration warning system to trigger the alert.
Following the incident, the commander notified ATC of the intention to attempt another takeoff and reduced the trim deflection to a safer position. After receiving clearance from ATC, the aircraft successfully departed without further complications.
Findings
- The primary cause of the incident was the positioning of the elevator trim at the limit of the green operating range.
- The pilot's decision to increase trim deflection to lighten the nose wheel during the roll brought the system to its warning threshold.