What happened
On 27 June 2011, a Cessna 172R operated by Singapore Flying College experienced a runway excursion during a solo training flight at Seletar Airport. After completing a dual sortie with an instructor, the student pilot proceeded with a solo flight. During the approach to Runway 21, Air Traffic Control notified the pilot of a 7-knot crosswind from 120 degrees.
While the aircraft initially maintained the centerline after touchdown, it suddenly drifted toward the left edge of the runway. The aircraft exited the paved surface and entered a grass patch, striking an Echo Taxiway signboard before the pilot managed to steer the aircraft back onto the runway, where it eventually came to a stop. There were no injuries to the pilot, but the aircraft sustained damage to the right aft fuselage and the left horizontal stabilizer, and the taxiway sign was dislocatated.
The investigation
Investigators from the TSIB examined the aircraft's mechanical systems, including the brakes, rudder, and nose wheel steering. All systems were found to be in normal working order, with no evidence of brake locking or mechanical failure. The investigation also reviewed the pilot's training and the meteorological conditions at the time of the incident.
Techniques for crosswind landings were analyzed, specifically focusing on the necessity of maintaining active aileron and rudder inputs throughout the landing roll. The investigation also looked into the training curriculum of the flying college regarding non-normal ground operations.
Findings
- The primary cause of the excursion was the pilot's insufficient rudder input to counteract the aircraft's leftward drift.
- The pilot initially applied only 20-30% of full right rudder, fearing that excessive input might lead to a loss of control, and later increased this to 40-50%, which remained inadequate to correct the veer.
- A potential contributing factor was the pilot's inadvertent reduction of control inputs, a common error where pilots relax aileron and rudder pressure once the aircraft is on the ground.
- The "weather-cock effect" likely exacerbated the situation, pulling the aircraft toward the wind direction.
- The flying college lacked a systematic training program or simulation to prepare student pilots for recovering an aircraft during non-normal ground situations, such as veering during the landing roll.