AD 2008-13-03
Recurring
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 747-400 Series | Airworthiness Directives; Boeing Model 747-400, 747-400D, and 747-400F Series Airplanes |
| aircraft | The Boeing Company | 747-400D Series | Airworthiness Directives; Boeing Model 747-400, 747-400D, and 747-400F Series Airplanes |
| aircraft | The Boeing Company | 747-400F Series | Airworthiness Directives; Boeing Model 747-400, 747-400D, and 747-400F Series Airplanes |
Unsafe Condition
Failure or cracking of the PCM manifold in the area of the yaw damper cavity endcap, which could result in an uncommanded left rudder hardover and increased pilot workload, potentially leading to runway departure upon landing.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect for cracking of the yaw damper actuator portion of the upper and lower rudder power control modules (PCMs). Replace the PCMs if necessary. Install a secondary retention device for the yaw damper modulating piston. Installation of the secondary retention device terminates the repetitive inspection requirements.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 50 flight hours after the effective date of the AD.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Model 747-400, 747-400D, and 747-400F series airplanes.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
The FAA is superseding an existing airworthiness directive (AD) that applies to all Boeing Model 747-400, 747-400D, and 747-400F series airplanes. That AD currently requires reviewing airplane maintenance records, doing repetitive inspections for cracking of the yaw damper actuator portion of the upper and lower rudder power control modules (PCMs), replacing the PCMs if necessary, and reporting all airplane maintenance records review and inspection results to the manufacturer. This new AD limits the applicability, reduces the initial inspection threshold and repetitive interval, removes the reporting requirement, and requires installation of a secondary retention device for the yaw damper modulating piston. Installation of the secondary retention device terminates the repetitive inspection requirements. This AD results from additional reports of failure or cracking of the PCM manifold in the area of the yaw damper cavity endcap at intervals well below the initial inspection threshold of the existing AD. We are issuing this AD to prevent an uncommanded left rudder hardover in the event of cracking in the yaw damper actuator portion of the upper or lower rudder PCMs, and subsequent failure of the PCM manifold, which could result in increased pilot workload, and possible runway departure upon landing.
Document Text
Show stored source text (verify against official source)
[Federal Register Volume 73, Number 119 (Thursday, June 19, 2008)]
[Rules and Regulations]
[Pages 34844-34847]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: E8-13561]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2008-0273; Directorate Identifier 2007-NM-369-AD;
Amendment 39-15566; AD 2008-13-03]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-400, 747-400D, and
747-400F Series Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The FAA is superseding an existing airworthiness directive
(AD) that applies to all Boeing Model 747-400, 747-400D, and 747-400F
series airplanes. That AD currently requires reviewing airplane
maintenance records, doing repetitive inspections for cracking of the
yaw damper actuator portion of the upper and lower rudder power control
modules (PCMs), replacing the PCMs if necessary, and reporting all
airplane maintenance records review and inspection results to the
manufacturer. This new AD limits the applicability, reduces the initial
inspection threshold and repetitive interval, removes the reporting
requirement, and requires installation of a secondary retention device
for the yaw damper modulating piston. Installation of the secondary
retention device terminates the repetitive inspection requirements.
This AD results from additional reports of failure or cracking of the
PCM manifold in the area of the yaw damper cavity endcap at intervals
well below the initial inspection threshold of the existing AD. We are
issuing this AD to prevent an uncommanded left rudder hardover in the
event of cracking in the yaw damper actuator portion of the upper or
lower rudder PCMs, and subsequent failure of the PCM manifold, which
could result in increased pilot workload, and possible runway departure
upon landing.
DATES: This AD becomes effective July 24, 2008.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in the AD as of July 24,
2008.
On October 13, 2006 (71 FR 52999, September 8, 2006), the Director
of the Federal Register approved the incorporation by reference of
Boeing Service Bulletin 747-27A2397, Revision 2, dated September 1,
2005.
[[Page 34845]]
ADDRESSES: For service information identified in this AD, contact
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
Examining the AD Docket
You may examine the AD docket on the Internet at <a href="http://www.regulations.gov">http://www.regulations.gov</a>; or in person at the Docket Management Facility
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this AD, the regulatory evaluation,
any comments received, and other information. The address for the
Docket Office (telephone 800-647-5527) is the Document Management
Facility, U.S. Department of Transportation, Docket Operations, M-30,
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE.,
Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: Douglas Tsuji, Aerospace Engineer,
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6487; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Discussion
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to include an AD that supersedes AD 2006-18-17, amendment
39-14756 (71 FR 52999, September 8, 2006). The existing AD applies to
all Boeing Model 747-400, 747-400D, and 747-400F series airplanes. That
NPRM was published in the Federal Register on March 13, 2008 (73 FR
13480). That NPRM proposed to continue to require reviewing airplane
maintenance records, doing repetitive inspections for cracking of the
yaw damper actuator portion of the upper and lower rudder power control
modules (PCMs), and replacing the PCMs if necessary. That NPRM also
proposed to add a requirement to install a secondary retention device
for the yaw damper modulating piston, and reduce the applicability.
Installation of the secondary retention device would terminate the
repetitive inspection requirements.
Comments
We provided the public the opportunity to participate in the
development of this AD. We have considered the comments that have been
received on the NPRM.
Support for the NPRM
Boeing, the National Transportation Safety Board (NTSB), and
Northwest Airlines (NWA) support, concur with, or have no objection to
the contents of the NPRM.
Request To Identify Other Part Numbers (P/Ns) in Parts Installation
Paragraph
Parker Hannifin Corporation, the PCM manufacturer, states that PCMs
that have P/Ns 332700-1009 and 333200-1009 should have been included in
paragraph (l), ``Parts Installation,'' of the NPRM. Parker states that
Parker Service Bulletins 332700-27-166 and 333200-27-167 required the
upper and lower PCMs to be marked with these part numbers as a
configuration change update. Parker states that it will rescind these
service bulletins. If these Parker service bulletins are not
accomplished, all identification plates will remain marked as P/Ns
332700-1007 and 333200-1007, which are both P/Ns identified in
paragraph (l) of the NPRM. However, Parker points out that it is
possible some PCMs have already been re-identified with the-1009 P/Ns.
Without including the-1009 P/Ns in paragraph (l) of this AD, these
parts would not be inspected and modified in accordance with the AD.
Therefore, Parker requests that we change paragraph (l) of this AD to
include these additional P/Ns.
We agree with Parker that it is important to ensure that P/Ns
332700-1009 and 333200-1009 are inspected and modified. It is also
important to encourage operators to consider this safety issue. These
P/Ns have the same potential for failure as the P/Ns listed in
paragraph (l) of the NPRM. However, we must allow time for the public
to comment on each additional requirement, and adding these P/Ns to
paragraph (l) of the AD would increase the scope of the AD by adding a
requirement. The degree of urgency associated with the unsafe condition
is such that we consider any delay to this action to be inappropriate.
Therefore, we have not changed the AD in this regard; however, we will
consider additional rulemaking to address P/Ns 332700-1009 and 333200-
1009.
Request To Clarify On-Airplane Modification
Air Transport Association (ATA), on behalf of United Airlines (UAL)
requests that we re-word paragraph (j) of the NPRM for clarity. UAL
indicates that the NPRM should state explicitly that it is acceptable
to modify the PCM while it is installed on the airplane. UAL points out
that this change would match the ``Relevant Service Information''
section of the NPRM.
We agree with the commenters' request to clarify this requirement.
It is acceptable to modify the PCM while it is installed on the
airplane. However, we understand that some operators might prefer the
option to do the modification while the PCM is not installed on the
airplane. Therefore, we have revised paragraph (j) of the AD to clarify
that either method of modification is acceptable.
Request To Clarify Correct Service Bulletin Tasks
ATA on behalf of UAL, requests that we revise the AD to clearly
state the correct service bulletin tasks for on-wing testing for PCMs
modified on-wing, and shop-level testing for PCMs removed from the
airplane. The commenters explain that the NPRM requires or refers to
four documents that specify testing methods after modifying the PCM:
Two component service bulletins (Parker Service Bulletins 332700-27-312
and 333200-27-314, both dated September 13, 2007), one Boeing service
bulletin (Boeing Alert Service Bulletin 747-27A2479, dated November 8,
2007), and the Boeing airplane maintenance manual (AMM). The commenters
state that a clarification would avoid compliance issues.
We agree that the numerous documents complicate the requirements.
However, the numerous documents are necessary to provide operators with
two options to modify the airplane. They can replace the existing PCM
with a PCM that has a yaw damper retention device, or install the yaw
damper retention device into the existing PCM on the airplane. We
disagree that it is necessary to change the AD in this regard. The
service information and the associated AMM sections clearly state which
tests must be performed, depending on whether the PCM is replaced or
modified while installed on the airplane.
Conclusion
We have carefully reviewed the available data, including the
comments that have been received, and determined that air safety and
the public interest require adopting the AD with the change described
previously. We have determined that this change will neither increase
the economic burden on any operator nor increase the scope of the AD.
Costs of Compliance
There are about 655 airplanes of the affected design in the
worldwide fleet. This AD affects about 86 airplanes of U.S. registry.
The following table provides the estimated costs for U.S.
[[Page 34846]]
operators to comply with this AD. The average labor rate is $80 per
work hour.
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Action Work hours Parts Cost per airplane Fleet cost
----------------------------------------------------------------------------------------------------------------
Ultrasonic inspection (required 4................. None.............. $320, per $27,520, per
by AD 2006-18-17). inspection cycle. inspection cycle.
Option 1--replacement (new Up to 22.......... Up to $4,496...... Up to $6,256...... Up to $538,016.
action).
Option 2--modification (new Up to 13.......... Up to $722........ Up to $1,762...... Up to $151,532.
action).
----------------------------------------------------------------------------------------------------------------
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, Section 106, describes the
authority of the FAA Administrator. Subtitle VII, Aviation Programs,
describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701, ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
Regulatory Findings
We have determined that this AD will not have federalism
implications under Executive Order 13132. This AD will not have a
substantial direct effect on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866;
(2) Is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and
(3) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
We prepared a regulatory evaluation of the estimated costs to
comply with this AD and placed it in the AD docket. See the ADDRESSES
section for a location to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
0
Accordingly, under the authority delegated to me by the Administrator,
the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
0
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by
removing amendment 39-14756 (71 FR 52999, September 8, 2006) and by
adding the following new airworthiness directive (AD):
2008-13-03 Boeing: Amendment 39-15566. Docket No. FAA-2008-0273;
Directorate Identifier 2007-NM-369-AD.
Effective Date
(a) This AD becomes effective July 24, 2008.
Affected ADs
(b) This AD supersedes AD 2006-18-17.
Applicability
(c) This AD applies to Boeing Model 747-400, 747-400D, and 747-
400F series airplanes, certificated in any category, as identified
in Boeing Alert Service Bulletin 747-27A2479, dated November 8,
2007.
Unsafe Condition
(d) This AD results from additional reports of failure or
cracking of the power control module (PCM) manifold in the area of
the yaw damper cavity endcap at intervals well below the initial
inspection threshold of the existing AD. We are issuing this AD to
prevent an uncommanded left rudder hardover in the event of cracking
in the yaw damper actuator portion of the upper or lower rudder
PCMs, and subsequent failure of the PCM manifold, which could result
in increased pilot workload, and possible runway departure upon
landing.
Compliance
(e) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.
Verification of Rudder PCM/Main Manifold Time-in-Service
(f) 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.
Ultrasonic Inspections
(g) Do an ultrasonic inspection for cracking of the yaw damper
actuator portion of the upper and lower rudder PCMs at the
applicable times specified in paragraph (g)(1) or (g)(2) of this AD
in accordance with the Accomplishment Instructions of Boeing Service
Bulletin 747-27A2397, Revision 2, dated September 1, 2005. Doing the
installation required by paragraph (j) of this AD ends the
inspection requirements of this paragraph for that PCM.
(1) For airplanes that have been inspected before the effective
date of this AD in accordance with Boeing Alert Service Bulletin
747-27A2397, dated July 24, 2003; Revision 1, dated March 31, 2005;
or Revision 2, dated September 1, 2005: Do the ultrasonic inspection
at the later of the times specified in paragraphs (g)(1)(i) and
(g)(1)(ii) of this AD. Repeat the inspection thereafter at intervals
not to exceed 7,000 flight hours or 1,125 flight cycles, whichever
occurs first, until the action required by paragraph (j) of this AD
is accomplished.
(i) Within 7,000 flight hours or 1,125 flight cycles after the
prior inspection, whichever occurs first.
(ii) Within 6 months after the effective date of this AD.
(2) For airplanes that have not been inspected before the
effective date of this AD in accordance with Boeing Alert Service
Bulletin 747-27A2397, dated July 24, 2003; Revision 1, dated March
31, 2005; or Revision 2, dated September 1, 2005: Do the ultrasonic
inspection at the later of the times specified in paragraphs
(g)(2)(i) and (g)(2)(ii) of this AD. Repeat the inspection
thereafter at intervals not to exceed 7,000 flight hours or 1,125
flight cycles, whichever occurs first,
[[Page 34847]]
until the action required by paragraph (j) of this AD is
accomplished.
(i) Prior to the accumulation of 14,000 total flight hours or
2,250 total flight cycles, whichever occurs first.
(ii) Within 6 months after the effective date of this AD.
Action if No Cracking Is Found
(h) If no cracking is found during any inspection required by
paragraph (g) of this AD: Before further flight, 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.
Action if Cracking Is Found
(i) If any cracking is found during any inspection required by
paragraph (g) of this AD: Before further flight, do the action in
paragraph (i)(1) or (i)(2) of this AD.
(1) Replace the affected PCM with a new or serviceable PCM in
accordance with the Accomplishment Instructions of Boeing Service
Bulletin 747-27A2397, Revision 2, dated September 1, 2005.
(2) Replace the PCM with a PCM that has the new secondary
retention device installed as specified in paragraph (j) of this AD.
Terminating Action
(j) Within 24 months or 8,400 flight hours after the effective
date of this AD, whichever occurs earlier: Install a new secondary
retention device for the yaw damper piston assembly in both the
upper and lower PCMs by either replacing the existing PCM with a new
improved PCM that already has the new secondary retention device, or
by modifying, testing, and re-identifying the existing PCM while the
PCM is installed on the airplane. Do the installation in accordance
with the Accomplishment Instructions of Boeing Alert Service
Bulletin 747-27A2479, dated November 8, 2007. Doing the installation
terminates the inspection requirements of this AD.
Note 1: Boeing Alert Service Bulletin 747-27A2479 refers to
Parker Service Bulletins 332700-27-312 and 333200-27-314, both dated
September 13, 2007, as additional sources of service information for
modifying the PCM.
Prior Accomplishment of Requirements
(k) Actions accomplished before October 13, 2006 (the effective
date of AD 2006-18-17), 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.
Parts Installation
(l) As of October 13, 2006, no person may 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, as specified by paragraph (g) of this AD.
Alternative Methods of Compliance (AMOCs)
(m)(1) The Manager, Seattle Aircraft Certification Office, FAA,
has the authority to approve AMOCs for this AD, if requested in
accordance with the procedures found in 14 CFR 39.19.
(2) To request a different method of compliance or a different
compliance time for this AD, follow the procedures in 14 CFR 39.19.
Before using any approved AMOC on any airplane to which the AMOC
applies, notify your appropriate principal inspector (PI) in the FAA
Flight Standards District Office (FSDO), or lacking a PI, your local
FSDO.
(3) AMOCs approved previously in accordance with AD 2006-18-17
are approved as AMOCs for the corresponding provisions of paragraphs
(g), (h), and (i) of this AD.
Material Incorporated by Reference
(n) You must use Boeing Service Bulletin 747-27A2397, Revision
2, dated September 1, 2005; and Boeing Alert Service Bulletin 747-
27A2479, dated November 8, 2007; as applicable; to perform the
actions that are required by this AD, unless the AD specifies
otherwise.
(1) The Director of the Federal Register approved the
incorporation by reference of Boeing Alert Service Bulletin 747-
27A2479, dated November 8, 2007, in accordance with 5 U.S.C. 552(a)
and 1 CFR part 51.
(2) October 13, 2006 (71 FR 52999, September 8, 2006), the
Director of the Federal Register approved the incorporation by
reference of Boeing Service Bulletin 747-27A2397, Revision 2, dated
September 1, 2005.
(3) Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207, for a copy of this service information. You
may review copies at the FAA, Transport Airplane Directorate, 1601
Lind Avenue SW., Renton, Washington; or at the National Archives and
Records Administration (NARA). For information on the availability
of this material at NARA, call 202-741-6030, or go to: <a href="http://www.archives.gov/federal-register/cfr/ibr-locations.html">http://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
Issued in Renton, Washington, on June 9, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-13561 Filed 6-18-08; 8:45 am]
BILLING CODE 4910-13-P
Source: Official FAA Source ↗
Retrieved: Apr 4, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.
Related Airworthiness Directives
2025-15-07 Recurring
final ruleAirworthiness Directives; The Boeing Company Airplanes
Unsafe Condition: uncommanded fore and aft movement of the Captain's and First Officer's seats, which could cause a flight control obstruction or unintended flight control input, resulting in the loss of the ability...
2025-09-08
final ruleAirworthiness Directives; The Boeing Company Airplanes
Unsafe Condition: Outboard elevators without balance weights could result in abnormal vibration, buffeting, flutter, or oscillation that could result in loss of continued safe flight and landing. Additionally, outbo...
2025-03-10
final ruleAirworthiness Directives; The Boeing Company Airplanes
Unsafe Condition: Separation of a fitting and steel water supply tube above an electronics equipment cooling air filter, behind the forward cargo compartment left sidewall, leading to water leaks into the main elect...
2025-02-05
final ruleAirworthiness Directives; The Boeing Company Airplanes
Unsafe Condition: improper inner diameter grinding of landing gear outer cylinders, resulting in possible heat damage to the outer cylinder of the nose landing gear (NLG), body landing gear (BLG), and wing landing g...
