AD 2001-03-10

[Federal Register Volume 66, Number 35 (Wednesday, February 21, 2001)]
[Rules and Regulations]
[Pages 10951-10953]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-3699]



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Federal Register / Vol. 66, No. 35 / Wednesday, February 21, 2001 / 
Rules and Regulations

[[Page 10951]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-206-AD; Amendment 39-12114; AD 2001-03-10]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100, -200, -300, -400, 
and 747SR 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 all Boeing Model 747-100, -200, -300, -400, and 747SR 
series airplanes; that requires a one-time inspection to determine 
whether H-11 steel bolts are installed as attach and support bolts at 
the trailing edge flap transmissions, and replacement of any H-11 steel 
bolt with an Inconel bolt. The actions specified by this AD are 
intended to prevent loss of a flap transmission, which could reduce 
lateral controllability of the airplane.

DATES: Effective March 28, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 28, 2001.

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: Barbara Mudrovich, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2983; 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 all Boeing Model 747-100, -200, -
300, -400, and 747SR series airplanes was published as a supplemental 
notice of proposed rulemaking (NPRM) in the Federal Register on May 31, 
2000 (65 FR 34604). That action proposed to require a one-time 
inspection to determine whether H-11 steel bolts are installed as 
attach and support bolts at the trailing edge flap transmissions, and 
replacement of any H-11 steel bolt with an Inconel bolt. That action 
also proposed to expand the applicability of the original NPRM to 
include additional airplanes.

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.

Request To Extend the Compliance Time

    Several commenters request that the compliance time for the 
proposed rule be extended. The commenters' suggestions for an 
appropriate compliance time range from 16 to 24 months. Most 
commenters' requests are based on the need for additional time so that 
subject H-11 steel bolts can be replaced during a scheduled maintenance 
visit. However, one commenter, who suggests that a compliance time of 
18 months would allow accomplishment of the AD during a heavy 
maintenance visit, also states that the replacement Inconel bolts 
listed in the service bulletin are not available in sufficient quantity 
to meet the needs of all affected operators. The commenter points out 
that, if adequate quantities of replacement bolts are not available, 
airplanes will be grounded. Similarly, another commenter requests that 
the FAA coordinate compliance times for this AD with the airplane 
manufacturer to ensure that an adequate supply of parts is available 
for replacement of the subject bolts on all airplanes in the worldwide 
fleet.
    The FAA concurs that the compliance time for the actions required 
by this AD may be extended. In developing an appropriate compliance 
time for this AD, the FAA considered not only the degree of urgency 
associated with addressing the subject unsafe condition, but the amount 
of time necessary to accomplish the necessary actions, the practical 
aspect of accomplishing the requirement within an interval of time that 
parallels normal scheduled maintenance for affected operators, and the 
availability of replacement parts. In consideration of these factors, 
the FAA has determined that 18 months represents an appropriate 
compliance time allowable wherein an acceptable level of safety can be 
maintained. Paragraph (a) of this AD has been revised accordingly.
    Though the FAA is extending the compliance time for the actions 
required by this AD, it should be noted that the FAA does not concur 
with the comment that the replacement Inconel bolts listed in the 
service bulletin are not available in sufficient quantity to meet the 
needs of all affected operators. The FAA has confirmed with the 
airplane manufacturer that an adequate supply of bolts is available.

Request To Provide Relief for Operators of Certain Airplanes

    One commenter requests various changes to the proposed rule to 
differentiate between airplanes delivered with H-11 steel bolts and 
airplanes not delivered with H-11 steel bolts, but that may have had 
such bolts installed as spares. The commenter states that, to avoid 
confusion, the proposed AD must be revised to make clear that H-11 
steel bolts were not used as attach and support bolts at the trailing 
edge flap transmissions in airplanes having line number (L/N) 872 and 
subsequent. The commenter asserts that, while this was apparent in the 
original NPRM, it was not clear in the supplemental NPRM. The purpose 
of the commenter's proposed changes is to provide relief to operators 
of airplanes not delivered with H-11 steel bolts. The commenter 
specifically requests that the FAA divide the applicability of the AD 
into three groups, and that operators of certain airplanes be given the 
option of examining the maintenance records to

[[Page 10952]]

determine if any major flap transmission or flap track repair or 
replacement has been done on the airplane. If no such repair or 
replacement has been done, no further action would be necessary for 
that airplane.
    The FAA concurs with the intent of the commenter's request, though 
not with the grouping of airplanes suggested by the commenter. The FAA 
finds that operators of airplanes that were not delivered with H-11 
steel bolts may be allowed to comply with this AD by inspecting the 
maintenance records for the airplane to determine if H-11 steel bolts 
may have been installed during a repair or replacement of a flap 
transmission or flap track. If the inspection of maintenance records 
conclusively shows that no major repair or replacement of a flap 
transmission or flap track has been done, then no further action is 
necessary for that airplane. Therefore, the FAA has revised this final 
rule to include a new paragraph (b), which offers operators of 
airplanes having L/N 872 and subsequent the option of an inspection of 
maintenance records to be performed instead of the inspection in 
paragraph (a) of this AD. (Subsequent paragraphs have been reordered 
accordingly.)

Request To Reduce Applicability

    One commenter disagrees with the expansion of the applicability 
that was proposed in the supplemental NPRM. The commenter states that 
it is an operator's responsibility to track components removed from one 
airplane and installed on another. The commenter states that it is 
unfair to penalize operators who are able to track components from 
airplane to airplane.
    The FAA concurs with the commenter's intent. As explained above, 
the FAA has added paragraph (b) to this final rule to give operators of 
airplanes that were not delivered with H-11 steel bolts the option to 
inspect the maintenance records for the airplane to determine if H-11 
steel bolts may have been installed during a repair or replacement. If 
the maintenance records conclusively show that no major repair or 
replacement of a flap transmission or flap track has been done, then no 
further action is necessary for that airplane. However, if it cannot be 
determined from the inspection of the maintenance records if such 
repair or replacement has been done, this AD requires an inspection for 
H-11 steel bolts, and follow-on corrective actions, if necessary. No 
further change to the final rule is necessary in this regard.

Request To Prohibit Future Installation of H-11 Steel Bolts

    One commenter requests that the FAA revise the proposed rule to 
include a statement that no airplane may be modified to introduce H-11 
steel bolts into the flap transmissions. The commenter states that such 
a statement is necessary to ensure that H-11 steel bolts are not 
installed in the flap transmissions of the subject airplanes (e.g., 
from spares) after the effective date of this AD. In a related issue 
addressed separately above, the same commenter proposes dividing the 
applicability of this AD into three groups, with one group of 
airplanes--those delivered after the effective date of this AD (Group 
3)--requiring no action per this AD.
    The FAA does not concur with the commenter's request. Revising the 
proposed rule to prohibit installation of H-11 steel bolts into the 
flap transmissions after the effective date of this AD would involve 
adding a new requirement to this AD, which would necessitate issuing 
another supplemental NPRM and reopening the public comment period. 
Considering the criticality of the unsafe condition, the FAA finds that 
it would be inappropriate to delay issuance of the final rule in this 
way. This AD will prohibit installation of H-11 steel bolts after 18 
months following the effective date of this AD, and the FAA finds that 
this 18-month interval is adequate to both ensure that all affected 
operators will be able to comply with this AD in a timely manner and 
ensure the safety of the affected airplane fleet. No change to the 
final rule is necessary in this regard.

Request To Allow Deferred Replacement of Bolts

    One commenter states that it ``seems strange'' that the FAA is 
allowing a compliance time of one year for the inspection but requiring 
the replacement before further flight of any H-11 steel bolt with an 
Inconel bolt. Another commenter points out that dispatch relief 
provided by Boeing Alert Service Bulletin 747-27A2376, dated July 1, 
1999, via a torque check of H-11 steel bolts was omitted from the 
proposed rule.
    The commenters make no specific request for a change to the 
proposed rule. However, the FAA infers that the commenters are 
requesting that the FAA allow deferred replacement of H-11 steel bolts 
that are not broken, as provided in the service bulletin. The FAA does 
not concur with this request. As explained in the original NPRM, though 
the service bulletin describes an option to defer replacement of an H-
11 steel bolt by performing a torque inspection to determine whether 
the H-11 steel bolt is broken, the FAA has determined that such a 
deferral would not result in the unsafe condition being addressed in a 
timely manner. In addition, as explained previously, the FAA is 
extending the compliance time for the inspection required by this AD 
from 12 to 18 months. This extension of the compliance time will allow 
operators to plan appropriately for doing this AD on their airplanes, 
so that the required actions may be done during a scheduled maintenance 
visit. No further change to this AD 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 1,240 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 281 airplanes of U.S. 
registry will be affected by this AD.
    The required inspection will take approximately 2 work hours per 
airplane at an average labor rate of $60 per work hour. Based on these 
figures, the FAA estimates the cost impact of this inspection on U.S. 
operators to be $33,720, or $120 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.
    Should an operator be required to accomplish the bolt replacement, 
it will take approximately 4 work hours per airplane (0.5 hour per 
transmission), at an average labor rate of $60 per work hour. Required 
parts will cost approximately $5,049 per airplane. Based on these 
figures, the FAA

[[Page 10953]]

estimates the cost impact of the replacement to be $5,289 per airplane.

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

    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:

2001-03-10  Boeing: Amendment 39-12114. Docket 99-NM-206-AD.

    Applicability: All Model 747-100, -100B, -100B SUD, -200B, -
200C, -200F, -300, -400, -400D, -400F, and 747SR series airplanes; 
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 (c) 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 loss of a flap transmission, which could reduce 
lateral controllability of the airplane, accomplish the following:

Replacement

    (a) Except as provided by paragraph (b) of this AD, within 18 
months after the effective date of this AD, perform a one-time 
general visual inspection to determine whether H-11 steel bolts are 
installed as attach and support bolts at the trailing edge flap 
transmissions, in accordance with Boeing Alert Service Bulletin 747-
27A2376, dated July 1, 1999.
    (1) If no H-11 steel bolt is found, no further action is 
required by this AD.
    (2) If any H-11 steel bolt is found, before further flight, 
replace with an Inconel bolt, in accordance with the alert service 
bulletin.

    Note 2:
    For the purposes of this AD, a general visual inspection is 
defined as: ``A visual examination of an interior or exterior area, 
installation, or assembly to detect obvious damage, failure, or 
irregularity. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or drop-light, and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''

Alternative Inspection for Certain Airplanes

    (b) For airplanes having line number (L/N) 872 and subsequent: 
Instead of doing paragraph (a) of this AD, it is acceptable to 
inspect airplane maintenance records to determine if a flap 
transmission or flap track repair or replacement has been done. This 
inspection of the maintenance records, if done, is required at the 
same 18-month compliance time as the inspection required by 
paragraph (a) of this AD.
    (1) If no flap transmission or flap track repair or replacement 
has been done: No further action is required by this AD.
    (2) If any flap transmission or flap track repair or replacement 
has been done, or if it cannot be determined from the inspection of 
the maintenance records if such repair or replacement has been done: 
Within 18 months after the effective date of this AD, do paragraph 
(a) of this AD.

Alternative Methods of Compliance

    (c) 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. 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

    (d) 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.

Incorporation by Reference

    (e) Except as provided by paragraph (b) of this AD, the actions 
shall be done in accordance with Boeing Alert Service Bulletin 747-
27A2376, dated July 1, 1999. 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.

Effective Date

    (f) This amendment becomes effective on March 28, 2001.

    Issued in Renton, Washington, on February 8, 2001.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-3699 Filed 2-20-01; 8:45 am]
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