Incident Description
On 25 September 2020, at approximately 14:10 local time, a flight instructor and a student boarded a SZD-9 bis 1E 'Bocian' glider (registration SP-2588) at Pobiednik Wielki airfield (EPKP) for a training flight using a winch launch. During pre-takeoff checks, the instructor observed that the elevator did not move through its full range of motion. Deeming the glider unairworthy, he released the towline and alerted the glider mechanic.
Investigation Findings
Maintenance personnel from the servicing organization inspected the glider and discovered that a pen cap was blocking the pushrod of the elevator control. The cap was located beneath a screw on the aileron control stick assembly in the second cockpit. After removing the pen cap, the control system functioned correctly.
Cause and Contributing Circumstances
The investigation determined that the cause of the incident was the accidental leaving of a pen cap in the glider cockpit. The circumstances leading to the presence of the pen cap could not be established.
Preventive Actions
Following the incident, the operating organization held a briefing with its personnel. Instructors and pilots were reminded of the importance of securing even small items in aircraft cockpits. Attention was drawn to the potential consequences of leaving objects within the glider structure and their possible impact on flight safety. Additionally, the need to perform thorough pre-flight checks, including verifying full movement of controls, brakes, and trim, was emphasized.