Airworthiness Directive · Amendment 39-9954 · Boeing Model 737 Series Airplanes
Boeing Model 737 Series Airplanes
Superseded. A later AD replaced this one: AD 2002-20-07, AD 2002-20-07 R1. Comply with the one in force.
Model 737 series airplanes, having a main rudder power control unit (PCU) that is identified in Boeing Service Letter 737-SL-27-112-B, dated February 6, 1997; certificated in any category.
This amendment adopts a new airworthiness directive (AD) that is applicable to all Boeing Model 737 series airplanes. This action requires removal of the main rudder power control unit (PCU) and replacement with a serviceable unit. This amendment is prompted by a report of the installation of an incorrect bolt on the main rudder PCU. The actions specified in this AD are intended to prevent cracking of the bearing of the main rudder PCU due to installation of an incorrect bolt; such cracking could result in seizure of the bearing and resultant uncommanded rudder movement.
