AD Amdt-39-11185

[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 [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[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]
BILLING CODE 4910-13-U