What happened
On May 29, 2010, a Beech C-90, registration OH-BEX, was performing a scheduled annual proficiency check flight at Mariehamn Airport. The flight, operated by Scanwings Oy, was intended to renew the type rating for the pilot being evaluated. The flight was conducted using a single-pilot method, with the trainee pilot occupying the left seat, which was atypical for this crew member.
During an ILS approach to runway 21, the aircraft was flying with flaps extended. Due to heavy rain, gusty winds, and a steeper-than-normal glidepath, the pilot's workload increased significantly. While attempting to manage airspeed and the glidepath, the pilot reduced power to a level that triggered the landing gear warning. The instructor pilot silenced the audible warning but did not verify the gear position.
As the aircraft approached the runway, the pilot failed to extend the landing gear. Upon reaching the threshold, the pilot realized the gear was still retracted and immediately initiated a go-around. During this maneuver, the propellers and several antennas on the underside of the fuselage struck the runway surface. The crew subsequently performed a second successful approach and landed normally. There were no injuries to the two crew members.
The investigation
The OTKES investigation examined the aircraft's maintenance history, the company's operational procedures, and the cockpit environment. Investigators found that the aircraft had been properly maintained and all certifications were valid. The investigation focused on the discrepancy between the company's established practice of having trainees fly from the left seat and the actual cockpit configuration and workload experienced during the approach.
Findings
- The primary cause of the incident was that the crew was overwhelmed by high workload caused by an atypical approach procedure combined with challenging weather conditions, leading them to fail to notice the landing gear was retracted.
- The trainee pilot had very little experience flying from the left-hand seat, as they typically operated from the right-hand seat.
- The crew used a multi-pilot checklist instead of a single-pilot checklist, which contributed to the oversight.
- The instructor pilot silenced the landing gear warning and failed to monitor the gear extension process.
- Adverse weather, including heavy rain and gusty winds, significantly increased the pilot's cognitive load.
- The company lacked specific written instructions for conducting these proficiency checks, relying instead on established practice and external forms.