[Federal Register: June 24, 2004 (Volume 69, Number 121)]
[Rules and Regulations]
[Page 35237-35239]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24jn04-4]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2002-NM-149-AD; Amendment 39-13682; AD 2004-13-02]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-100, -200B, and -200F
Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Boeing Model 747-100, -200B, and -200F series
airplanes. This action requires initial and repetitive inspections to
find discrepancies in the upper and lower skins of the fuselage lap
joints, and repair if necessary. This action is necessary to find and
fix such discrepancies, which could result in sudden fracture and
failure of a lap joint and rapid in-flight decompression of the
airplane fuselage. This action is intended to address the identified
unsafe condition.
DATES: Effective July 29, 2004.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of July 29, 2004.
ADDRESSES: The service information referenced in this AD may be
obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207. This information may be examined 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.
FOR FURTHER INFORMATION CONTACT: Nick Kusz, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
917-6432; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to certain Boeing Model 747-100, -
200B, and -200F series airplanes was published in the Federal Register
on July 2, 2003 (68 FR 39483). That action proposed to require initial
and repetitive inspections to find discrepancies in the upper and lower
skins of the fuselage lap joints, and repair if necessary.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the single comment received.
Request To Withdraw the Notice of Proposed Rulemaking
One commenter states that the proposed rule, as it applies to Model
747 series airplanes, is unnecessary, will not improve safety, and
imposes an undue burden on airplane operators. The commenter suggests
that there is a tenuous connection between the 737 incident and the 747
fleet. The commenter further states that Model 747 series airplanes
have a stronger design than Model 737 series airplanes; that Model 747
series airplanes have existing modifications and modification
requirements; and that Model 747 series airplanes are better maintained
by U.S. operators. In addition, this commenter recently completed
``full modification'' of eighteen upper lobe lap joints on an affected
Model 747 series airplane and found no evidence of scratches.
The FAA infers from these comments that the commenter is requesting
that the proposed rule be withdrawn. We do not agree. To date, no
reports of cracks and scratches in the subject area have been found on
Model 747 series airplanes. In consideration of this fact, we specified
a longer compliance time in this AD for Model 747 series airplanes than
the compliance time for Model 737 series airplanes specified in AD
2000-17-04, amendment 39-11878 (65 FR 51750, August 25, 2002). We chose
repetitive intervals of 72 months for the required low frequency eddy
current (LFEC) inspections in order to minimize the effect on the
operators while still providing an adequate level of safety. In
addition, we determined that the possibility of scratches that initiate
during manufacture exists for any cold-bonded adhesive skin panel, and
that there have been numerous reports of corrosion on cold bonded skin
panels in Boeing Model 747 series airplanes. Corrosion has also been
reported on Boeing Model 747 series airplanes on which full
modification has previously been accomplished per AD 90-06-06,
amendment 39-6490 (55 FR 8374, March 7, 1990); and AD 94-12-09
amendment 39-8937 (59 FR 30285, June 13, 1994). For these reasons, it
is both warranted and necessary to issue this AD.
Remove Certain Inspection Requirements
The same commenter requests that the LFEC inspections for corrosion
at the upper fastener rows should not be required at locations that
have had ``full modifications'' accomplished per Boeing Alert Service
Bulletin 747-53A2267, dated March 28, 1986
[[Page 35238]]
(required by AD 94-17-01, amendment 39-8996 (59 FR 41653, August 15,
1994)), or Boeing Service Bulletin 747-53-2307, Revision 1, dated
August 27, 1992 (required by AD 94-12-09). The commenter states that
the ``full modifications'' are sufficient to detect and remove damage,
and that the post-modification inspections required by AD 94-12-09 and
the SSID AD (AD 94-15-18, amendment 39-8989, 59 FR 41233, August 11,
1994)) provide an equivalent level of safety in detecting subsequent
damage.
We do not agree that the external LFEC inspections should not be
required for operators that have accomplished the modifications
required by Boeing Alert Service Bulletin 747-53A2267 or Boeing Service
Bulletin 747-53-2307. We have received reports from the manufacturer of
corrosion on airplanes on which the full modification had been
accomplished. While the re-sealing process included in the full
modification does provide some level of improvement in surface
protection, it does not provide enough of an improvement to prevent
corrosion.
We also do not agree that the post-modification inspections
required by AD 94-12-09 and the SSID AD (AD 94-15-18) provide an
equivalent level of safety. The post-modification external high
frequency eddy current (HFEC) inspections required by AD 94-12-09 and
AD 94-17-01 address cracks only in the upper row on the surface of the
upper skin. The external LFEC inspections required by this AD address
corrosion beneath the surface, at the interface between the upper and
lower skins. We have not changed the final rule regarding these issues.
Include Alternative Method of Compliance (AMOC) for Repaired Airplanes
The same commenter suggests that the proposed AD include specific
instructions for conducting inspections where existing repairs may
interfere with or obstruct the required inspections. The commenter also
suggests that these potential obstructions will result in an exorbitant
number of requests for AMOCs, and that the industry and the FAA are ill
equipped to handle the number of requests. Further, the manufacturer
has informed the commenter that a revision to Boeing Alert Service
Bulletin 747-53A2463 (which is referenced in this AD as the appropriate
source of service information for the required actions) is being
prepared to include instructions to account for existing repairs.
While we agree that it would be preferable to cite specific
instructions for inspections at repaired areas, we cannot include such
instructions until we receive the revised service bulletin from the
manufacturer. At that time, we will review the revised service bulletin
and, upon our approval of the new requirements, we will consider
further rulemaking. We have not changed the final rule regarding this
issue.
Conclusion
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 as proposed.
Change to Labor Rate Estimate
We have reviewed the figures we have used over the past several
years to calculate AD costs to operators. To account for various
inflationary costs in the airline industry, we find it necessary to
increase the labor rate used in these calculations from $60 per work
hour to $65 per work hour. The cost impact information, below, reflects
this increase in the specified hourly labor rate.
Cost Impact
There are approximately 86 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 55 airplanes of U.S. registry
will be affected by this proposed AD, that it will take approximately
5,334 work hours per airplane to accomplish the inspections, and that
the average labor rate is $65 per work hour. Based on these figures,
the cost impact of this AD on U.S. operators is estimated to be
$19,069,050, or $346,710 per airplane.
The 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 cost impact figures discussed
in AD rulemaking actions represent only the time necessary to perform
the specific actions actually required by the AD. These figures
typically do not include incidental costs, such as the time required to
gain access and close up, planning time, or time necessitated by other
administrative actions.
Regulatory Impact
The regulations adopted herein 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. Therefore, it
is determined that this final rule does not have federalism
implications under Executive Order 13132.
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
0
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
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. Section 39.13 is amended by adding the following new airworthiness
directive:
2004-13-02 Boeing: Amendment 39-13682. Docket 2002-NM-149-AD.
Applicability: Model 747-100, -200B, and -200F series airplanes,
as listed in Boeing Alert Service Bulletin 747-53A2463, dated March
7, 2002; certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To find and fix discrepancies in the upper and lower skins of
the fuselage lap joints, which could result in sudden fracture and
failure of a lap joint and rapid in-flight decompression of the
airplane fuselage, accomplish the following:
Initial and Repetitive Inspections
(a) Do the applicable (initial and repetitive) inspections as
specified in Figures 2 through 8, as applicable, of the
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2463, including Appendices A, B, and C, dated March 7, 2002, to
find discrepancies (cracking and corrosion) in the upper and lower
skins of the fuselage lap joints. Do the inspections at the
applicable times specified in Figure 1 of the
[[Page 35239]]
Accomplishment Instructions of the alert service bulletin, in
accordance with the alert service bulletin; except that where Figure
1 specifies a compliance time of ``after the release date of this
service bulletin,'' this AD requires a compliance time of ``after
the effective date of this AD.'' Where Figure 1 specifies a
compliance time of ``flight cycles'' this AD requires a compliance
time of ``total flight cycles.''
(b) Where Boeing Alert Service Bulletin 747-53A2463, including
Appendices A, B, and C, dated March 7, 2002, specifies that the
manufacturer may be contacted for certain inspection procedures,
inspect per a method approved by the Manager, Seattle Aircraft
Certification Office (ACO), FAA; or per data meeting the type
certification basis of the airplane approved by a Boeing Company
Designated Engineering Representative (DER) who has been authorized
by the Manager, Seattle ACO, to make such findings.
Adjustments to Compliance Time: Cabin Differential Pressure
(c) For the purposes of calculating the compliance threshold and
repetitive interval for the inspections required by paragraph (a) of
this AD: Flight cycles in which cabin differential pressure is at
2.0 pounds per square inch (psi) or less need not be counted when
determining the number of flight cycles that have occurred on the
airplane, provided that flight cycles with momentary spikes in cabin
differential pressure above 2.0 psi are included as full pressure
flight cycles. For this provision to apply, all cabin pressure
records must be maintained for each airplane. No fleet-averaging of
cabin pressure is allowed.
Repair
(d) Before further flight, repair any discrepancy (cracking or
corrosion) found during any inspection required by paragraph (a) of
this AD, per the Accomplishment Instructions of Boeing Alert Service
Bulletin 747-53A2463, including Appendices A, B, and C, dated March
7, 2002. If any discrepancy is found and the alert service bulletin
specifies that the manufacturer may be contacted for disposition of
certain repairs, before further flight, repair per a method approved
by the Manager, Seattle ACO; or per data meeting the type
certification basis of the airplane approved by a Boeing Company DER
who has been authorized by the Manager, Seattle ACO, to make such
findings.
Alternative Methods of Compliance
(e) In accordance with 14 CFR 39.19, the Manager, Seattle ACO,
is authorized to approve alternative methods of compliance for this
AD.
Incorporation by Reference
(f) Unless otherwise specified in this AD, the actions shall be
done in accordance with Boeing Alert Service Bulletin 747-53A2463,
including Appendices A, B, and C, dated March 7, 2002. This
incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Copies may be obtained from Boeing Commercial Airplanes, 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.
Effective Date
(g) This amendment becomes effective on July 29, 2004.
Issued in Renton, Washington, on June 9, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-13866 Filed 6-23-04; 8:45 am]
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