70-25-07 BOEING: Amdt. 39-1125. Applies to Model 707 and 720 Series airplanes listed in Boeing Service Bulletin 2998, dated October 1, 1970, or later FAA approved revisions. \n\n\tTo prevent fluid bypassing within the Rudder Power Control Unit (PCU) accomplish the following: \n\n\tWithin the next 300 hours' time in service after the effective date of this AD, unless previously accomplished, modify the Rudder PCU in accordance with Boeing Service Bulletin 2998, dated October 1, 1970, or later FAA approved revision or an equivalent method approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\tThis amendment becomes effective December 11, 1970.