AD 2005-04-03
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 747-400 Series | Airworthiness Directives; Boeing Model 747-400, -400D, and -400F Series Airplanes |
| aircraft | The Boeing Company | 747-400D Series | Airworthiness Directives; Boeing Model 747-400, -400D, and -400F Series Airplanes |
| aircraft | The Boeing Company | 747-400F Series | Airworthiness Directives; Boeing Model 747-400, -400D, and -400F Series Airplanes |
Unsafe Condition
Disengagement of all three flap control units (FCUs) at the same time, leading to loss of primary flaps control and flaps indication display.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace at least one flap control unit (FCU) in the main equipment center with a new or modified FCU, in accordance with Boeing Alert Service Bulletin 747-27A2386, dated March 13, 2003. Concurrently, perform actions specified in Boeing Service Bulletin 747-27-2319, dated January 24, 1991.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 60 months after the effective date of the final rule (March 25, 2005).
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Model 747-400, -400D, and -400F series airplanes.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 747-400, -400D, and -400F series airplanes. This AD requires replacing at least one flap control unit (FCU) in the main equipment center with a new or modified FCU. This AD is prompted by a report indicating that, after takeoff, an airplane was required to return to the airport because the autopilot disengaged. The report also indicated that, after selecting flaps for landing, the flaps indication display did not indicate the flap setting, requiring the airplane to land in alternate flap mode. We are issuing this AD to prevent disconnection of autoland/autopilot functions and loss of primary flaps control and flaps indication display due to disengagement of all three FCUs at the same time, which could lead to a non-normal high speed landing with the flaps retracted, increased pilot workload, and possible runway departure at high speeds during landing.
Document Text
Show stored source text (verify against official source)
[Federal Register Volume 70, Number 33 (Friday, February 18, 2005)]
[Rules and Regulations]
[Pages 8239-8241]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 05-2843]
[[Page 8239]]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2004-18999; Directorate Identifier 2003-NM-259-AD;
Amendment 39-13975; AD 2005-04-03]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-400, -400D, and -400F
Series Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Boeing Model 747-400, -400D, and -400F series airplanes. This
AD requires replacing at least one flap control unit (FCU) in the main
equipment center with a new or modified FCU. This AD is prompted by a
report indicating that, after takeoff, an airplane was required to
return to the airport because the autopilot disengaged. The report also
indicated that, after selecting flaps for landing, the flaps indication
display did not indicate the flap setting, requiring the airplane to
land in alternate flap mode. We are issuing this AD to prevent
disconnection of autoland/autopilot functions and loss of primary flaps
control and flaps indication display due to disengagement of all three
FCUs at the same time, which could lead to a non-normal high speed
landing with the flaps retracted, increased pilot workload, and
possible runway departure at high speeds during landing.
DATES: This AD becomes effective March 25, 2005.
The incorporation by reference of certain publications listed in
the AD is approved by the Director of the Federal Register as of March
25, 2005.
ADDRESSES: For service information identified in this AD, contact
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207. You can examine this information 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/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>.
Docket: The AD docket contains the proposed AD, comments, and any
final disposition. You can examine the AD docket on the Internet at
<a href="http://dms.dot.gov">http://dms.dot.gov</a>, or in person at the Docket Management Facility
office between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the U.S.
Department of Transportation, 400 Seventh Street, SW., room PL-401,
Washington, DC. This docket number is FAA-2004-18999; the directorate
identifier for this docket is 2003-NM-259-AD.
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 98055-
4056; telephone (425) 917-6487; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR Part 39
with an AD for certain Boeing Model 747-400, -400D, and -400F series
airplanes. That action, published in the Federal Register on September
7, 2004 (69 FR 54060), proposed to require replacing at least one flap
control unit (FCU) in the main equipment center with a new or modified
FCU.
Comments
We provided the public the opportunity to participate in the
development of this AD. We have considered the comments that have been
submitted on the proposed AD.
Agrees With Proposed AD
One commenter agrees with the proposed AD.
Request To Reduce the Compliance Time
One commenter requests that the compliance time specified in
paragraph (f)(1) of the proposed AD be reduced. The commenter states
that the 60-month compliance time is too long and should be shortened
substantially due to the potential severity of the situation (i.e.,
landing without flaps) and the nature of the proposed modifications.
The commenter believes that the availability of parts necessary to
complete the modifications is not an issue.
The FAA does not agree to reduce the compliance time specified in
paragraph (f)(1) of the final rule. In developing the compliance time
for this AD, we considered the average utilization rate of the affected
fleet, the practical aspects of an orderly modification of the fleet
during regular maintenance periods, and the availability of required
parts as well as the safety implications of the identified unsafe
condition. In addition, the low probability of the identified unsafe
condition occurring (disengagement of all three flap control units
(FCU) causing loss of primary flaps control and flaps indication
display) and the existing operational manual bulletin that provides
guidance to the crew for extending the flaps in alternate mode in the
absence of indication are consistent with longer compliance times.
Based on these factors, the proposed compliance time of 60 months after
the effective date of the final rule was determined to be appropriate.
Further, we arrived at the proposed compliance time with manufacturer
concurrence. We have not changed the final rule in this regard.
Request To Remove Paragraph (g) of the Proposed AD
One commenter requests that paragraph (g) of the proposed AD be
removed. The commenter states that paragraph (g) of the proposed AD
would require actions specified in Boeing Service Bulletin 747-27-2319,
dated January 24, 1991, to be done before or concurrently with
paragraph (f) of the proposed AD. The commenter notes that the actions
in paragraph (f) of the proposed AD are to be done according to Boeing
Alert Service Bulletin 747-27A2386, dated March 13, 2003, and that the
alert service bulletin specifies in paragraph 1.B. that ``you cannot
make the changes in this service bulletin unless the changes given in
Boeing Service Bulletin 747-27-2319 are made.'' Thus, the commenter
believes there is no need for paragraph (g) of the proposed AD.
We do not agree to remove paragraph (g) of the final rule. We agree
that paragraph (f) of the final rule requires the actions to be done
``in accordance with the Accomplishment Instructions of Boeing Alert
Service Bulletin 747-27A2386, dated March 13, 2003'' and that paragraph
1.B. of the alert service bulletin refers to the concurrent actions
that are specified in paragraph (g) of the final rule. However,
paragraph 1.B. of the alert service bulletin precedes the
Accomplishment Instructions of the alert service bulletin. Because the
Accomplishment Instructions of the alert service bulletin do not
specify to do any concurrent action, paragraph (g) of the final rule is
needed to clarify that the concurrent action must be done. We have not
changed the final rule in this regard.
Request for Clarification of Test
One commenter points out that paragraph 3.B.2. of the Boeing Alert
Service Bulletin 747-27A2386 specifies that a built-in test equipment
(BITE) test be done according to Chapter 27-51-51 of the Boeing 747-400
airplane maintenance manual (AMM). The
[[Page 8240]]
commenter notes that there is no BITE test in either 27-51-00/501 or
27-51-51/401 of the Boeing 747-400 AMM. The commenter contends the
alert service bulletin refers to a test that does not exist and is not
necessary. The commenter also states that the alert service bulletin
specifies installing the FCU in accordance with Chapter 27-51-51 of the
Boeing 747-400 AMM and that the referenced AMM specifies to do an
operational test of the FCU that includes both a central maintenance
computer initiated ground test and exercising the flaps through full
travel to ensure proper operation and indication.
We infer from the comment that the commenter requests that the
reference to the BITE test be clarified. We partially agree. We
acknowledge that paragraph 3.B.2. of the alert service bulletin
specifies a BITE test be done according to Chapter 27-51-51 of the
Boeing 747-400 AMM. However, Chapter 27-51-51 of the Boeing 747-400 AMM
refers to a BITE test only in the summary of the AMM procedure, but not
within the body of the AMM procedure. Within the body of the AMM
procedure, there is a ``GROUND TEST,'' under the heading ``OPERATIONAL
TEST,'' that is to be done following installation of the FCU. Although
the nomenclature within the Boeing documents may seem inconsistent, we
consider the ``GROUND TEST'' specified in Chapter 27-51-51 of the
Boeing 747-400 AMM to be part of the FCU BITE test. Furthermore,
Chapter 27-51-51 of the Boeing 747-400 AMM includes all necessary
testing that must be done following installation of a new FCU. In
addition, because the final rule references only the alert service
bulletin, there is no need to add a clarification of the BITE test to
the final rule. We have not changed the final rule in this regard.
Conclusion
We have carefully reviewed the available data, including the
comments that have been submitted, and determined that air safety and
the public interest require adopting the AD as proposed.
Costs of Compliance
There are about 614 airplanes of the affected design worldwide.
This AD will affect about 87 airplanes of U.S. registry. The following
tables provide the estimated costs for U.S. operators to comply with
this AD.
----------------------------------------------------------------------------------------------------------------
Average
Replacement Work hours labor rate Parts Cost per
per hour airplane
----------------------------------------------------------------------------------------------------------------
Estimated Costs
----------------------------------------------------------------------------------------------------------------
With new -208 FCU........................................... 2 $65 $78,550 $78,680
With modified -208 FCU...................................... 10 65 975 1,625
-------------------------------------------------------------
Estimated Concurrent Service Bulletin Costs
----------------------------------------------------------------------------------------------------------------
With new -207 FCU........................................... 3 65 235,650 235,845
With modified -207 FCU...................................... 87 65 2,925 8,580
----------------------------------------------------------------------------------------------------------------
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. 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]
0
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive (AD):
2005-04-03 Boeing: Amendment 39-13975. Docket No. FAA-2004-18999;
Directorate Identifier 2003-NM-259-AD.
Effective Date
(a) This AD becomes effective March 25, 2005.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Model 747-400, -400D, and -400F series
airplanes, certificated in any category, as identified in Boeing
Alert Service Bulletin 747-27A2386, dated March 13, 2003.
Unsafe Condition
(d) This AD was prompted by a report indicating that, after
takeoff, an airplane was required to return to the airport because
the autopilot disengaged. The report also
[[Page 8241]]
indicated that, after selecting flaps for landing, the flaps
indication display did not indicate the flap setting, requiring the
airplane to land in alternate flap mode. We are issuing this AD to
prevent disconnection of autoland/autopilot functions and loss of
primary flaps control and flaps indication display due to
disengagement of all three flap control units (FCUs) at the same
time, which could lead to a non-normal high speed landing with the
flaps retracted, increased pilot workload, and possible runway
departure at high speeds during 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.
Replace FCU
(f) At the earliest of the times specified in paragraphs (f)(1),
(f)(2), and (f)(3) of this AD: Replace at least one FCU having P/N
285U0011-207 with a new or modified FCU having P/N 285U0011-208 in
accordance with the Accomplishment Instructions of Boeing Alert
Service Bulletin 747-27A2386, dated March 13, 2003.
(1) Within 60 months after the effective date of this AD.
(2) Within 25,000 flight hours after the effective date of this
AD.
(3) Within 4,000 flight cycles after the effective date of this
AD.
Note 1: Boeing Alert Service Bulletin 747-27A2386, dated March
13, 2003, refers to Boeing Component Service Bulletin 285U0011-27-
06, dated March 13, 2003, as an additional source of service
information for modifying an FCU having P/N 285U0011-207 to P/N
285U0011-208.
Actions Required Before or Concurrently With Paragraph (f)
(g) For airplanes identified in Boeing Service Bulletin 747-27-
2319, dated January 24, 1991: Before or concurrent with the
accomplishment of paragraph (f) of this AD, replace the three FCUs
having P/N 285U0011-205 or 285U0011-206 with new or modified FCUs
having P/N 285U0011-207 in accordance with the Accomplishment
Instructions of Boeing Service Bulletin 747-27-2319, dated January
24, 1991.
Note 2: Boeing Service Bulletin 747-27-2319, dated January 24,
1991, refers to Boeing Component Service Bulletin 285U0011-27-04,
dated January 24, 1991, as an additional source of service
information for modifying the FCUs having P/N 285U0011-205 or
285U0011-206 to P/N 285U0011-207.
Parts Installation
(h) As of the effective date of this AD, no person may install
on any airplane an FCU having P/N 285U0011-205 or -206.
Alternative Methods of Compliance (AMOCs)
(i) The Manager, Seattle Aircraft Certification Office, FAA, has
the authority to approve AMOCs for this AD, if requested using the
procedures found in 14 CFR 39.19.
Material Incorporated by Reference
(j) You must use Boeing Alert Service Bulletin 747-27A2386,
dated March 13, 2003; and Boeing Service Bulletin 747-27-2319, dated
January 24, 1991; as applicable; to perform the actions that are
required by this AD, unless the AD specifies otherwise. The Director
of the Federal Register approves the incorporation by reference of
these documents in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. For copies of the service information, contact Boeing Commercial
Airplanes, PO Box 3707, Seattle, Washington 98124-2207. For
information on the availability of this material at the National
Archives and Records Administration (NARA), call (202) 741-6030, or
go to <a href="http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>. You may view the AD docket at the
Docket Management Facility, U.S. Department of Transportation, 400
Seventh Street SW., room PL-401, Nassif Building, Washington, DC.
Issued in Renton, Washington, on February 3, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-2843 Filed 2-17-05; 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.