Despite being categorised as mandatory for the pilot’s seat by the aircraft manufacturer, a secondary seat stop modification designed to prevent uncommanded rearward pilot seat movement and potential loss of control was not fitted to VH-FRT, nor was it required to be under United States or Australian regulations.
The ATSB recommends that the Civil Aviation Safety Authority takes action to strengthen incorporation of Cessna Single Engine Service Bulletin SEB07-5 Secondary seat stop modification.
CASA intends to comply with the ATSB recommendation by the following means:
Update the current AWB 53-010 Issue 1 - Cessna Pilot's Secondary Seat Stop Installation of Modification Kit - SEB07-5 to further emphasise the importance of:
Furthermore, the AWB is planned to be re-titled to be under ATA 25 to be more easily found with other similar AWBs for seats and cabin furnishings; and
As mentioned in the CASA comments to the draft report, CASA also intends to legislate through an amendment to Schedule 5, for the daily inspection, a task to cover checking condition and security of seat stop hardware.
On 23 April 2018, CASA released Airworthiness Bulletin (AWB) 25-032 Issue 1- Cessna Pilot Seat Track Locking – Pre-flight Check, Maintenance and Mod Status. That AWB recommended most of the information included in the initial response. Further to that, the AWB highlighted the issues identified in this ATSB investigation and the importance of the secondary seat stop system.
The ATSB recognises the safety action that CASA has implemented to improve relevant Cessna aircraft pilot seat/seat track maintenance and inspection requirements. Additionally, they have increased industry awareness about seat slide events and strongly encouraged the installation and use of secondary seat stop modification.
The ATSB’s preferred safety action was, and remains, for CASA to issue an Airworthiness Directive mandating installation of the Cessna secondary seat stop modification. However, it is expected that the net result of the safety action implemented by CASA has decreased the risk of Cessna seat slide events from occurring. For that reason, the ATSB considers that the safety issue has been adequately addressed.
The ATSB encourages CASA to review the effectiveness of the AWB in addressing the safety issue identified by the ATSB with respect to the installation of the secondary seat stop.
