Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 737-600, -700, -700C, -800, and "900 series airplanes. This action requires repetitive tests of the rudder pedal force or repetitive inspections of the rudder feel and centering unit to determine the condition of the inner spring; corrective action if necessary; and eventual replacement of the spring assembly on the rudder feel and centering unit with a new assembly, which would terminate the repetitive requirements. This action is necessary to prevent reduced rudder pedal feel and centering force, which, combined with failure of the outer spring of the spring assembly, could result in pilot-induced oscillation and consequent loss of control of the airplane. This action is intended to address the identified unsafe condition.