Accident Summary
On 28 May 2017 at approximately 9:58 local time, a Cessna 185A, registration SP-AKZ, operated by Aeroklub Kielecki, suffered an accident during the initial takeoff roll at Masłów airfield (EPKA). The aircraft was conducting a parachute drop operation with four skydivers aboard. The pilot, a 67-year-old male with an ATPL license and extensive experience, reported that his seat suddenly slid backward during takeoff power application, causing him to lose control of the rudder pedals. He simultaneously reduced engine power and pulled back on the yoke. The aircraft yawed approximately 220 degrees and came to rest beside the runway about 80 meters from the start of the takeoff roll.
Aircraft and Crew
The aircraft was a Cessna 185A, registration SP-AKZ, owned and operated by Aeroklub Kielecki. The pilot held a valid ATPL(A) license with SEP(L) and FI ratings. He had a total flight time of 13,991 hours and 24 minutes. The pilot and the four skydivers were uninjured.
Sequence of Events
Earlier that day, the pilot arrived at Masłów at about 9:00. He performed a pre-flight inspection and conducted two practice circuits before the accident flight. At 9:38, the pilot and four skydivers boarded. After engine start, the pilot obtained radio clearance to taxi to runway 11. Before entering the runway, he checked control deflections, engine parameters, and braced his feet against the rudder pedals to verify the seat was locked. Satisfied, he requested and received clearance to take off. Upon advancing the throttle to maximum, his seat suddenly slid backward, preventing rudder control. The pilot reduced power and pulled back on the yoke. The aircraft turned about 220 degrees and stopped beside the runway. After stopping, the pilot shut down the engine, fuel, and master switch. He asked if anyone was hurt; all occupants evacuated without injury. Police and the State Commission for Aircraft Accident Investigation (PKBWL) were notified. The pilot tested negative for alcohol.
Damage
The aircraft sustained damage to the right wheel rim and tire, the right main landing gear leg was torn off, the first frame at the engine mount was damaged, the fuselage skin in the center section was wrinkled, the right part of the front windshield was torn out, and the skin of the right wing and left engine cowling was wrinkled.
Cause and Contributing Factors
The probable cause of the accident was pilot error consisting of incorrect seat locking. Contributing factors were an inoperative inertia mechanism and an improperly installed strap of the seat anti-slide system. The seat locking pin was not fully engaged, and the safety mechanism had been bypassed by attaching the strap directly to the seat belt attachment point.
The investigation noted that the pilot positioned the seat fully forward. When he pressed the seat lock lever, it lifted the left front mounting bracket out of the rail at a cutout intended for seat removal. The asymmetric frame deformation prevented positive locking. During the pre-takeoff check, the pilot's forward lean may have increased the pin pressure. During takeoff, inertial forces caused the seat to slide back.