[Federal Register Volume 64, Number 106 (Thursday, June 3, 1999)]
[Rules and Regulations]
[Pages 29778-29781]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-13878]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-51-AD; Amendment 39-11185; AD 99-11-14]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 767 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 767 series airplanes, that requires
detailed visual inspections to detect corrosion or chrome plating
cracks on the fuse pins of the outboard support of the main landing
gear (MLG) beam. This AD also would require either installation of the
existing fuse pins and repetitive inspections; or installation of
newer-type fuse pins, which constitutes terminating action for the
repetitive inspections. This amendment is prompted by a report
indicating that corrosion was found on a fuse pin in the outboard
support of the MLG beam. The actions specified by this AD are intended
to detect and correct such corrosion and cracking, which could result
in the failure of a fuse pin and, consequently, lead to collapse of the
MLG.
DATES: Effective July 8, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of July 8, 1999.
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: James G. Rehrl, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington; telephone (425) 227-2783;
fax (425) 227-1181.
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
[[Page 29779]]
Model 767 series airplanes was published in the Federal Register on
July 15, 1998 (63 FR 38120). That action proposed to require detailed
visual inspections to detect corrosion or chrome plating cracks on the
fuse pins, load distribution plates, and bushings of the outboard
support of the main landing gear (MLG) beam. That action also proposed
to require either installation of the existing fuse pins and repetitive
inspections; or installation of newer-type fuse pins, which would
constitute terminating action for the repetitive inspections.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Support for the Proposal
Several commenters support the proposed rule.
Removal of References to Bushings and Load Distribution Plates
Several commenters request that all references to the bushings and
load distribution plates specified in the proposal be removed. One
commenter states that all references to these items have been removed
in the latest revision (Revision 3) of Boeing Service Bulletin 767-
57A0054. (Boeing Alert Service Bulletin 767-57A0054, Revision 2, dated
April 18, 1996, was referenced in the proposal as the appropriate
source of service information for accomplishment of the required
actions.) Another commenter requests that the proposed inspection of
the bushings and load distribution plates be removed, or if not
removed, that accomplishment of the inspection, rework, and fabrication
be performed in accordance with Component Maintenance Manual 57-54-23.
The commenters state that the unsafe condition in the proposed AD
is related to cracking of the fuse pins and is not in any way related
to discrepancies of the bushings and load distribution plates.
The FAA concurs with the commenters' requests. The FAA has
determined that the structural integrity of the bushings and load
distribution plates is indeed not an issue, and therefore all
references to the bushings and load distribution plates have been
removed from the final rule.
In addition, the final rule has been revised to include Boeing
Service Bulletin 767-57A0054, Revision 3, dated October 30, 1997, as an
additional source of service information. The FAA finds that this new
revision is essentially the same as Revision 2 of the alert service
bulletin. However, Revision 3 removes all references to the load
distribution plates and bushings described in Revision 2 of the service
bulletin.
Request To Allow Class 2 Chrome Plating Finish on Fuse Pins
One commenter requests that the proposed rule be changed to allow a
chrome plating finish requirement of Class 2 or better on the 15-5PH
CRES fuse pins. The commenter states that the Class 3 plating
requirement for the fuse pins is excessive because Class 2 chrome
plating is an effective shield against corrosion, and the substrate of
the 15-5PH CRES fuse pins is less susceptible to corrosion than the
older 4330M steel fuse pins. The commenter also indicates that the
requirement for Class 3 chrome plating adds an unwarranted restriction
at the next overhaul.
The FAA does not concur with the commenter's request to allow a
chrome plating finish requirement of Class 2 or better on the 15-5PH
CRES fuse pins, for several reasons:
1. As stated in the AD, the installation of the 15-5PH CRES fuse
pins (with Class 3 chrome plating) is not required, but is an optional
terminating action.
2. The new 15-5PH CRES fuse pins (with Class 3 chrome plating) were
selected for the configuration because they are an improvement in that
they are less susceptible to corrosion than the older 4330M steel fuse
pins (with Class 2 chrome plating). Considering that Class 2 chrome
plating has a history of disbonding from the steel substrate, the FAA
finds it practical to select an improved process (i.e., Class 3
plating) for the new, more corrosion-resistant fuse pins.
3. The FAA reiterates that the pins called out in the service
bulletin have already been manufactured with the improved Class 3
chrome plating. Compliance with this AD, and even with the optional
terminating action (which is the portion of the AD that specifically
calls for the installation of the 15-5PH CRES fuse pins), does not
generate any excess burden on any operator by specifying that the new
15-5PH CRES fuse pins, as procured, have Class 3 chrome plating.
4. The FAA concludes that the commenter has misinterpreted that the
AD requires Class 3 chrome plating be applied to the 4330M steel fuse
pins, when, in fact, the AD does not. It requires that the existing
4330M steel fuse pins (with Class 2 plating) be repetitively inspected,
or, as an optional terminating action, replaced with improved 15-5PH
CRES fuse pins (with Class 3 plating).
5. Finally, in reference to the commenter's statement that Class 3
chrome plating adds an unwarranted restriction at the next overhaul,
this AD does not require the existing 4330M steel fuse pins to be
repaired with Class 3 plating at overhaul, nor does the AD describe any
overhaul practices. Therefore, no change to the final rule is necessary
in this regard.
Requests To Limit Applicability
One commenter requests that the applicability of the proposed rule
be revised to include only those airplanes with fuse pins that have
been identified by the manufacturer as substandard. The commenter
states that the manufacturer has been able to connect inferior batches
of fuse pins provided by certain suppliers to specific airplane line
positions.
The FAA does not concur with the commenter's request. The
manufacturer has not provided the FAA with any information that
connects inferior batches of fuse pins to specific airplane line
positions. Without such substantiating information, the FAA has no
justification to revise the applicability of the final rule.
Another commenter requests that the applicability of the proposed
rule be revised to exclude those airplanes on which 15-5PH CRES fuse
pins have already been installed. The commenter states that the
installation of the newer type 15-5PH CRES fuse pins addresses the
unsafe condition and, therefore, airplanes with those pins installed
are not affected by the proposed rule.
The FAA concurs with the commenter in that installation of the new
fuse pins addresses the unsafe condition as stated in the final rule.
Therefore, the applicability of the final rule has been revised
accordingly.
Request To Revise Cost Impact Information
One commenter states that the service information contains more
complete information than the preamble of the proposal and reflects a
more accurate statement of the actual costs of the proposal. Although
no specific change was requested by the commenter, the FAA infers that
the commenter wants the cost impact section of the proposed rule to be
revised to reflect the time required to gain access to the area and to
return the airplane to normal service.
The FAA does not concur. The FAA acknowledges that the cost impact
information, below, describes only the ``direct'' costs of the specific
actions
[[Page 29780]]
required by this AD. The FAA recognizes that, in accomplishing the
requirements of any AD, operators may incur ``incidental'' costs in
addition to the ``direct'' costs. The cost analysis in AD rulemaking
actions, however, typically does not include incidental costs, such as
the time required to gain access and close up, planning time, or time
necessitated by other administrative actions. Because incidental costs
may vary significantly from operator to operator, they are almost
impossible to calculate. Therefore, attempting to estimate such costs
would be futile. No change to the final rule is necessary in this
regard.
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 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.
Cost Impact
There are approximately 609 Boeing Model 767 series airplanes of
the affected design in the worldwide fleet. The FAA estimates that 151
airplanes of U.S. registry will be affected by this AD, that it will
take approximately 4 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 cost impact of this AD on U.S. operators is
estimated to be $36,240, or $240 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.
Regulatory Impact
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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
99-11-14 Boeing: Amendment 39-11185. Docket 97-NM-51-AD.
Applicability: Model 767 series airplanes, line numbers 1
through 609 inclusive; certificated in any category; having 4330M
steel fuse pins installed in the outboard support of the main
landing gear (MLG) beam.
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 (e) 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 detect and correct corrosion and cracking of the fuse pins in
the outboard support of the MLG beam, which could result in the
failure of a fuse pin and, consequently, lead to collapse of the
MLG, accomplish the following:
Detailed Visual Inspection
(a) Within 4 years of service since the MLG was new, or within
18 months after the effective date of this AD, whichever occurs
later, perform detailed visual inspections of the fuse pins of the
MLG outboard support beam to detect corrosion or chrome plating
cracks on the fuse pin, in accordance with the Accomplishment
Instructions of Boeing Alert Service Bulletin 767-57A0054, Revision
2, dated April 18, 1996, or Boeing Service Bulletin 767-57A0054,
Revision 3, dated October 30, 1997.
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.''
Corrective Actions
(b) If any corrosion or plating crack of a fuse pin is found
during any inspection required by paragraph (a) of this AD, prior to
further flight, accomplish either paragraph (b)(1) or (b)(2) of this
AD.
(1) Install a new or serviceable 4330M steel fuse pin in
accordance with the Accomplishment Instructions of Boeing Alert
Service Bulletin 767-57A0054, Revision 2, dated April 18, 1996, or
Boeing Service Bulletin 767-57A0054, Revision 3, dated October 30,
1997. Repeat the detailed visual inspections required by paragraph
(a) of this AD thereafter at intervals not to exceed 48 months. Or
(2) Install a newer-type 15-5PH CRES fuse pin in accordance with
the Accomplishment Instructions of Boeing Alert Service Bulletin
767-57A0054, Revision 2, dated April 18, 1996, or Boeing Service
Bulletin 767-57A0054, Revision 3, dated October 30, 1997.
Accomplishment of this installation constitutes terminating action
for the repetitive inspection requirements of paragraphs (a),
(b)(1), and (c)(1) of this AD.
(c) If no corrosion or plating crack is found on the fuse pins,
prior to further flight, accomplish the requirements of either
paragraph (c)(1) or (c)(2) of this AD in accordance with the
Accomplishment Instructions of Boeing Alert Service Bulletin 767-
57A0054, Revision 2, dated April 18, 1998, or Boeing Service
Bulletin 767-57A0054, Revision 3, dated October 30, 1997.
(1) Install the existing 4330M steel fuse pins in accordance
with the Accomplishment Instructions of the service bulletin. Repeat
the detailed visual inspections required by paragraph (a) of this AD
thereafter at intervals not to exceed 48 months. Or
(2) Install newer-type 15-5PH CRES fuse pins in accordance with
the Accomplishment Instructions of the service bulletin.
Accomplishment of this installation constitutes terminating action
for the repetitive inspection requirements of paragraphs (a),
(b)(1), and (c)(1) of this AD.
[[Page 29781]]
Alternative Methods of Compliance
(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 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
(e) Special flight permits may be issued in accordance with
Secs. 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.
Incorporation by Reference
(f) The actions shall be done in accordance with Boeing Alert
Service Bulletin 767-57A0054, Revision 2, dated April 18, 1996; or
Boeing Service Bulletin 767-57A0054, Revision 3, dated October 30,
1997. 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 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 8, 1999.
Issued in Renton, Washington, on May 21, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-13878 Filed 6-2-99; 8:45 am]
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