Airworthiness Directive · Amendment 39-14756 · Boeing Model 747-400, 747-400D, and 747-400F Series Airplanes
Boeing Model 747-400, 747-400D, and 747-400F Series Airplanes
Superseded. A later AD replaced this one: AD 2008-13-03. Comply with the one in force.
This AD applies to all Boeing Model 747-400, 747-400D, and 747-400F series airplanes, certificated in any category.
The FAA is superseding an existing airworthiness directive (AD), which applies to certain Boeing Model 747-400, 747-400D, and 747- 400F series airplanes. The existing AD currently requires reviewing airplane maintenance records; inspecting the yaw damper actuator portion of the upper and lower rudder power control modules (PCMs) for cracking, and replacing the PCMs if necessary; and reporting all airplane maintenance records review and inspection results to the manufacturer. This new AD expands the applicability and discontinues certain requirements of the existing AD. This AD adds repetitive inspections of the PCMs, and replacement of the PCMs if necessary. This AD results from manufacturer findings that the inspections required by the existing AD must be performed at regular intervals. We are issuing this AD to detect and correct cracking in the yaw damper actuator portion of the upper and lower rudder PCMs, which could result in an uncommanded left rudder hardover, consequent increased pilot workload, and possible runway departure upon landing.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
For any affected airplane, if it can be positively verified that any rudder PCM or PCM main manifold installed on that airplane has accumulated a different total of flight hours or flight cycles than the totals accumulated by that airplane, the flight cycles or flight hours accumulated by the rudder PCM or PCM main manifold will be acceptable as valid starting points for meeting the compliance times required by this AD.
For airplanes which, prior to the effective date of this AD, have received an ultrasonic inspection for cracking of the yaw damper actuator portion of the upper and lower rudder PCM, in accordance with Boeing Alert Service Bulletin 747-27A2397, dated July 24, 2003, as required by AD 2003-23-01: Do paragraphs (g)(1), (g)(2), (g)(3), and (g)(4) of this AD, as applicable, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-27A2397, Revision 2, dated September 1, 2005.
(1) Perform the ultrasonic inspection described in paragraph (g) of this AD at the later of the times specified in paragraph (g)(1)(i) or (g)(1)(ii) of this AD, then do paragraph (g)(2) or (g)(3) of this AD, as applicable; and paragraph (g)(4) of this AD.
(i) Within 28,000 flight hours or 4,500 flight cycles after the date of the prior inspection, whichever occurs first.
(ii) Within 24 months after the effective date of this AD.
(2) If no cracking is found during any inspection required by paragraph (g)(1) or (h) of this AD: Apply sealant and a torque stripe and install a lockwire on the rudder PCM in accordance with the Accomplishment Instructions and Figure 1 or Figure 2, as applicable, of Boeing Service Bulletin 747-27A2397, Revision 2, dated September 1, 2005.
(3) If any cracking is found during any inspection required by paragraph (g)(1) or (h) of this AD: Before further flight, replace the affected PCM with a new or serviceable PCM and submit the report required by paragraph (i) of this AD.
(4) Repeat the ultrasonic inspection described in paragraph (g) of this AD at intervals not to exceed 28,000 flight hours or 4,500 flight cycles, whichever occurs first, and repeat the actions in paragraph (g)(2) or (g)(3) of this AD, as applicable.
For airplanes not inspected prior to the effective date of this AD as specified in paragraph (g) of this AD: At the later of the times specified in paragraph (h)(1) or (h)(2) of this AD, perform an ultrasonic inspection for cracking of the yaw damper actuator portion of the upper and lower rudder PCM main manifold; and do the actions specified in paragraph (g)(2) or (g)(3) of this AD, as applicable; in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-27A2397, Revision 2, dated September 1, 2005. Repeat the inspection thereafter at intervals not to exceed 28,000 flight hours or 4,500 flight cycles, whichever occurs first.
(1) Prior to the accumulation of 56,000 total flight hours or 9,000 total flight cycles, whichever occurs first.
(2) Within 24 months after the effective date of this AD.
(i) For all airplanes: At the applicable time specified in paragraph (i)(1) or (i)(2) of this AD, accomplish the actions in paragraph (j) of this AD.
(1) If the inspection was done after the effective date of this AD: Submit the report and part, if applicable, within 30 days after the inspection.
(2) If the inspection was done before the effective date of this AD: Submit the report and part, if applicable, within 30 days after the effective date of this AD.
(j) At the applicable time specified in paragraph (i) of this AD: Do the requirements of paragraphs (j)(1) and (j)(2) of this AD. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.
(1) If any inspection required by this AD reveals any indication of a cracked or broken part, submit a report to: The Boeing Company, Service Engineering—Mechanical Systems. The report must contain the airplane and rudder PCM serial numbers, the total flight hours and flight cycles for each rudder PCM (and rudder PCM main manifold, if known), and a description of any damage found. Submission of the Inspection Report Form (Figure 3 of Boeing Service Bulletin 747-27A2397, Revision 2, dated September 1, 2005) is one acceptable method of complying with this requirement.
(2) Send any cracked or broken PCMs or manifolds to Parker Hannifin Corporation in accordance with the shipping instructions specified in Appendix A of Boeing Alert Service Bulletin 747-27A2397, Revision 2, dated September 1, 2005.
Actions accomplished before the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-27A2397, dated July 24, 2003; or Revision 1, dated March 31, 2005; are considered acceptable for compliance with the corresponding requirements of this AD.
As of the effective date of this AD, no person shall install on any airplane a rudder PCM having a top assembly part number (P/N) 332700-1003, -1005, or -1007; or P/N 333200-1003, -1005, or -1007; unless the PCM has been ultrasonically inspected and found to be without cracks; in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-27A2397, Revision 2, dated September 1, 2005.
