[Federal Register Volume 60, Number 125 (Thursday, June 29, 1995)]
[Rules and Regulations]
[Pages 33683-33685]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-14632]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-251-AD; Amendment 39-9280; AD 95-12-27]


Airworthiness Directives; Boeing Model 747-400 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain Boeing Model 747-400 series airplanes, that 
currently requires a revision to the input wiring for the flap control 
unit (FCU). This amendment requires a new systems test for the wiring 
of the trailing edge flap, and also expands the applicability of the 
existing AD to include additional airplanes. This amendment is prompted 
by a report indicating that a wiring error was not detected by the 
system test required by the existing AD. The actions specified by this 
AD are intended to prevent the possibility of an all-flaps-up landing 
due to the loss of control of all flap operations.

DATES: Effective July 31, 1995.
    The incorporation by reference of Boeing Service Bulletin 747-
27A2346, Revision 2, dated January 12, 1995, as listed in the 
regulations, is approved by the Director of the Federal Register as of 
July 31, 1995.
    The incorporation by reference of Boeing Service Bulletin 747-
27A2346, Revision 1, dated May 19, 1994, as listed in the regulations, 
was approved previously by the Director of the Federal Register as of 
August 10, 1994 (59 FR 35240, July 11, 1994).

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Kristin Larson, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, Seattle Aircraft Certification 

[[Page 33684]]
Office, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056; telephone (206) 227-1760; fax (206) 227-
1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 94-14-21, 
amendment 39-8970 (59 FR 35240, July 11, 1994), which is applicable to 
certain Boeing Model 747-400 series airplanes, was published in the 
Federal Register on February 15, 1995 (60 FR 8591). The action proposed 
to continue to require a revision of the input wiring for the flap 
control unit (FCU), but would include the addition of a new systems 
test for the wiring of the trailing edge flap. The action also proposed 
to expand the applicability of the existing AD to include additional 
airplanes.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    The manufacturer states that the numbers referred to as ``serial 
numbers'' in paragraphs (a), (b), and (c) of the proposal are 
designated incorrectly, and requests that the numbers be referred to as 
``line numbers.'' The FAA concurs and has revised paragraphs (a), (b), 
and (c) of the final rule to reflect this change.
    One commenter requests that the additional systems test for the 
wiring, as proposed in paragraph (c) in the AD, be deleted. The 
commenter states that this testing is unnecessary because the specific 
procedures provided by Boeing Service Bulletin 747-27A2346, Revision 1, 
dated May 19, 1994 (which is the appropriate source of service 
information for existing AD 94-14-21), ensure that the wires are 
installed in the correct pin locations. The FAA does not concur. This 
AD was prompted by a report from an operator indicating that a wiring 
error of the landing gear module was discovered after the 
accomplishment of the wiring systems check required by AD 94-14-21. The 
FAA has determined that the wiring systems check required by that AD 
does not provide adequate verification that the wiring modification was 
made correctly. Therefore, the additional systems check as specified in 
paragraph (c) of the final rule is required.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    There are approximately 310 Model 747-400 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 36 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 0.5 work hours per airplane to accomplish the 
required actions, and that the average labor rate is $60 per work hour. 
Based on these figures, the total cost impact of the AD on U.S. 
operators is estimated to be $1,080, or $30 per airplane.
    The total cost impact figure discussed above is based on 
assumptions that no operator has yet accomplished any of the 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.
    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-8970 (59 FR 
35240, July 11, 1994), and by adding a new airworthiness directive 
(AD), amendment 39-9280, to read as follows:

95-12-27  Boeing: Amendment 39-9280. Docket 94-NM-251-AD. Supersedes 
AD 94-14-21, Amendment 39-8970.

    Applicability: Model 747-400 series airplanes having line 
numbers 696 through 1036 inclusive; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must use the authority 
provided in paragraph (d) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.

    Note 2: Paragraph (a) of this AD merely restates the 
requirements of paragraph (a) of AD 94-14-21, amendment 39-8970. As 
allowed by the phrase, ``unless accomplished previously,'' if those 
requirements of AD 94-14-21 have already been accomplished, this AD 
does not require that those actions be repeated.

    To prevent the possibility of an all-flaps-up landing due to the 
loss of control of flap operations, accomplish the following:
    (a) For airplanes having line numbers 696 through 1019 
inclusive, and 1021 through 1026 inclusive: Within 30 days after 
August 10, 1994 (the effective date of AD 94-14-21, amendment 39-
8970), revise the input wiring for the flap control unit (FCU) in 
accordance with Boeing Service Bulletin 747-27A2346, Revision 1, 
dated May 19, 1994, or Revision 2, dated January 12, 1995.
    (b) For airplanes having line numbers 1020, and 1027 through 
1036 inclusive: Within 30 days after the effective date of this AD, 
revise the input wiring for the FCU in accordance with Boeing 
Service Bulletin 747-27A2346, Revision 2, dated January 12, 1995.
    (c) For airplanes having line numbers 696 through 1036 
inclusive: Within 120 days after the effective date of this AD, 
perform the additional systems test for the wiring of the trailing 
edge flap in accordance with Boeing Service Bulletin 747-27A2346, 
Revision 2, dated January 12, 1995. 

[[Page 33685]]

    (d) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA, Transport Aircraft Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Seattle ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (e) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.
    (f) The wire systems test and wiring revision shall be done in 
accordance with Boeing Service Bulletin 747-27A2346, Revision 1, 
dated May 19, 1994, and Boeing Service Bulletin 747-27A2346, 
Revision 2, dated January 12, 1995. The incorporation by reference 
is approved by the Director of the Federal Register in accordance 
with 5 U.S.C. 552(a) and 1 CFR part 51. The incorporation by 
reference of Boeing Service Bulletin 747-27A2346, Revision 1, dated 
May 19, 1994, was approved previously by the Director of the Federal 
Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51 as of 
August 10, 1994 (59 FR 35240, July 11, 1994). Copies may be obtained 
from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. Copies may be inspected at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or 
at the Office of the Federal Register, 800 North Capitol Street, 
NW., suite 700, Washington, DC.
    (g) This amendment becomes effective on July 31, 1995.

    Issued in Renton, Washington, on June 9, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-14632 Filed 6-28-95; 8:45 am]
BILLING CODE 4910-13-U