[Federal Register Volume 64, Number 226 (Wednesday, November 24, 1999)]
[Proposed Rules]
[Pages 66119-66121]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-30631]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-132-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 767 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Boeing Model 767 series
airplanes. This proposal would require repetitive inspections of the
side load underwing fitting bushings for broken sealant or bushing
migration, and corrective action, if necessary. This proposal would
also provide optional terminating action in lieu of repetitive
inspections. This proposal is prompted by reports of migrated bushings
and corrosion on the side load fittings. The actions specified by the
proposed AD are intended to prevent corrosion in the side load
underwing fitting, which could result in cracking and consequent
reduced structural integrity of the wing strut.
DATES: Comments must be received by January 10, 2000.
[[Page 66120]]
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-132-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except
Federal holidays.
The service information referenced in the proposed rule may be
obtained from Boeing Commercial Airplane Group, 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.
FOR FURTHER INFORMATION CONTACT: James G. Rehrl, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-2783; fax (425) 227-1181.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications shall identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 99-NM-132-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules
Docket No. 99-NM-132-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received reports of migrated bushings on the side load
underwing fittings on Boeing Model 767 series airplanes. Where migrated
bushings were found, several cases of corrosion of the side fitting lug
bore were reported. Migration of the side load fitting bushing breaks
the moisture barrier to the fitting bore, and can cause corrosion of
the fitting bore. Bushing migration can also cause damage to the
adjacent structure when the bushing contacts the adjacent structure as
it migrates outward. This condition, if not corrected, could result in
cracking and consequent reduced structural integrity of the wing strut.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Service Bulletin 767-57-
0063, dated May 7, 1998, which describes procedures for repetitive
detailed visual inspections of the side load underwing fitting bushings
for broken sealant or bushing migration, and corrective action, if
necessary. The corrective action includes reworking the side load
fitting and installing a new bushing, if necessary. The service
bulletin also describes optional terminating action to rework the side
load fitting that may be accomplished in lieu of repetitive detailed
visual inspections.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design registered
in the United States, the proposed AD would require accomplishment of
the actions specified in the service bulletin described previously.
This proposed AD also would provide for optional terminating action for
the repetitive inspections.
Operators should note that the FAA has determined that the
repetitive inspections proposed by this AD can be allowed to continue
in lieu of accomplishment of a terminating action. In making this
determination, the FAA considers that, in this case, long-term
continued operational safety will be adequately assured by
accomplishing the repetitive inspections to detect broken sealant or
bushing migration of the side load fitting bushing before it represents
a hazard to the airplane.
Differences Between the Proposed Rule and the Service Bulletin
Boeing Service Bulletin 767-57-0063, dated May 7, 1998, specifies
that the manufacturer may be contacted for disposition of certain
repair conditions, this proposed AD would require the repair of those
conditions to be accomplished in accordance with a method approved by
the FAA, or in accordance with data meeting the type certification
basis of the airplane approved by a Boeing Company Designated
Engineering Representative who has been authorized by the FAA to make
such findings. For a repair method to be approved by the Manager,
Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane
Directorate, as specified in paragraph (d) of this proposed AD, the
Manager's approval letter must specifically reference this AD.
Cost Impact
There are approximately 663 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 312 airplanes of U.S. registry
would be affected by this proposed AD, that it would take approximately
4 work hours per airplane to accomplish the proposed inspection, and
that the average labor rate is $60 per work hour. Based on these
figures, the cost impact of the proposed AD on U.S. operators is
estimated to be $74,880, or $240 per airplane, per inspection cycle.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the proposed requirements of
this AD action, and that no operator would accomplish those actions in
the future if this AD were not adopted.
Should an operator elect to accomplish the optional terminating
action rather than continue the repetitive inspections, it would take
approximately 12 work hours per airplane to accomplish the
modification, at an average labor rate of $60 per work hour.
Required parts would cost approximately $1,500 per airplane. Based
on these figures, the cost impact of this optional terminating action
is estimated to be $2,220 per airplane.
Regulatory Impact
The regulations proposed herein would 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
[[Page 66121]]
12612, it is determined that this proposal would not have sufficient
federalism implications to warrant the preparation of a Federalism
Assessment.
For the reasons discussed above, I certify that this proposed
regulation (1) is not a ``significant regulatory action'' under
Executive Order 12866; (2) is not a ``significant rule'' under the DOT
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979);
and (3) if promulgated, 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 copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting the Rules
Docket at the location provided under the caption ``ADDRESSES.''
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Boeing: Docket 99-NM-132-AD.
Applicability: Model 767 series airplanes, as listed in Boeing
Service Bulletin 767-57-0063, dated May 7, 1998; 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 request approval for an
alternative method of compliance in accordance with paragraph (f) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To prevent corrosion in the side load underwing fitting, which
could result in cracking and consequent reduced structural integrity
of the wing strut, accomplish the following:
Initial Inspection
(a) Accomplish a detailed visual inspection of the side load
underwing fitting to detect broken sealant or bushing migration, in
accordance with Boeing Service Bulletin 767-57-0063, dated May 7,
1998, at the later of the times specified in paragraphs (a)(1) and
(a)(2) of this AD.
(1) Within 10 years since the date of manufacture, or
(2) Within 3000 cycles or 18 months after the effective date of
this AD, whichever occurs first.
Note 2: For the purposes of this AD, a detailed visual
inspection is defined as: ``An intensive visual examination of a
specific structural area, system, installation, or assembly to
detect damage, failure, or irregularity. Available lighting is
normally supplemented with a direct source of good lighting at
intensity deemed appropriate by the inspector. Inspection aids such
as mirror, magnifying lenses, etc., may be used. Surface cleaning
and elaborate access procedures may be required.''
Repetitive Inspections
(b) If no broken sealant or evidence of bushing migration is
detected, repeat the inspection required by paragraph (a) of this AD
thereafter at intervals not to exceed 6 years.
Corrective Action
(c) If evidence of broken sealant or bushing migration is
detected, prior to further flight, accomplish the corrective action
specified in paragraph (c)(1) or (c)(2) of this AD, except as
provided by paragraph (d) of this AD.
(1) Remove the bushing and inspect the side load fitting lug
bore for corrosion as shown in Figure 3 of Boeing Service Bulletin
767-57-0063, dated May 7, 1998, and rework as specified in Figure 3
of the service bulletin.
(2) Reseal the bushing and service the side load fitting in
accordance with Boeing Service Bulletin 767-57-0063, dated May 7,
1998. Within 3,000 flight cycles or 18 months, whichever occurs
first, remove the bushing and inspect the side load fitting lug bore
for corrosion as shown in Figure 3 of the service bulletin, and
rework as specified in Figure 3 of the service bulletin.
(d) For airplanes on which broken sealant or evidence of bushing
migration is detected: During the accomplishment of the actions
specified in paragraphs(c)(1) or (c)(2) of this AD, if damage to the
lug bore or fitting is found that is outside the limits specified in
Boeing Service Bulletin 767-57-0063, dated May 7, 1998; prior to
further flight, repair in accordance with a method approved by the
Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport
Airplane Directorate; or in accordance with data meeting the type
certification basis of the airplane approved by a Boeing Company
Designated Engineering Representative who has been authorized by the
FAA to make such findings. For a repair method to be approved by the
Manager, Seattle ACO, as required by this AD, the Manager's approval
letter must specifically reference this AD.
Optional Terminating Action
(e) Accomplishment of rework of the side load fitting in
accordance with Figure 1 or Figure 3 of Boeing Service Bulletin 767-
57-0063, dated May 7, 1998, constitutes terminating action for the
requirements of this AD.
Alternative Methods of Compliance
(f) 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 Airplane 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.
Special Flight Permits
(g) 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.
Issued in Renton, Washington, on November 18, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-30631 Filed 11-23-99; 8:45 am]
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