Summary
We propose to adopt a new airworthiness directive (AD) for certain Cessna Aircraft Company (Cessna) Models 172R, 172S, 182S, 182T, T182T, 206H, and T206H airplanes. This proposed AD would require you to install Modification Kit MN172-25-10B or a steel lock rod/bar on both crew seat back cylinder lock assemblies. If a steel lock rod/bar has already been installed on the crew seat back cylinder lock assembly, no further action is required. If Modification Kit MK172-25-10A has previously been installed, this proposed AD would require you to do an installation inspection and correct any discrepancies found. This proposed AD results from reports of the crew seat back cylinder lock assembly failing at the aft end and other cylinder lock assemblies found cracked. We are proposing this AD to prevent the crew seat cylinder lock assembly from bending, cracking, or failing. This failure could cause uncontrolled movement of the seat back, resulting in possible backward collapse during flight. Backward collapse of either crew seat back could result in an abrupt pitch-up if the affected crew member continues to hold on to the control yoke during this failure and could cause difficulty in exiting the airplane from an aft passenger seat after landing.