Airworthiness Directives; Boeing Model 757 Series Airplanes

[Federal Register Volume 66, Number 227 (Monday, November 26, 2001)]
[Rules and Regulations]
[Pages 58922-58924]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-29186]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-405-AD; Amendment 39-12513; AD 2001-23-14]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757 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 757 series airplanes, that requires 
a review of maintenance records or an inspection to determine the 
serial numbers of geared rotary actuators (GRA) for the leading edge 
slats, and replacement of certain actuators with new or reworked 
actuators. This action is necessary to prevent a fractured spring 
washer in a GRA, which could lead to a disconnect in the GRA, and 
result in a slat skew condition and consequent reduced controllability 
of the airplane. This action is intended to address the identified 
unsafe condition.

DATES: Effective December 31, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 31, 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 certain Boeing Model 757 series 
airplanes was published in the Federal Register on May 15, 2001 (66 FR 
26819). That action proposed to require an inspection to determine the 
serial numbers of geared rotary actuators (GRA) for the leading edge 
slats, and replacement of certain actuators with new or reworked 
actuators.

Comments Received

    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 Proposed Rule

    One commenter supports the proposed rule.

Requests To Allow Review of Maintenance Records

    Two commenters request that, in lieu of the inspection of the GRAs 
in paragraph (a) of the proposed AD, we allow a review of the 
maintenance records to determine the part number series and serial 
number for each installed GRA for the leading edge slats. One of the 
commenters states that if an operator tracks installed parts by serial 
number, that operator ought to be allowed to use its records to 
demonstrate compliance.
    We concur and have revised paragraph (a) to allow a review of the 
airplane's maintenance records as an acceptable means of determining 
the part number series and serial number for each installed GRA for the 
leading edge slats.

Request To Extend Compliance Time

    One commenter requests that the FAA extend the compliance time for 
the proposed requirements to 36 months for all affected airplanes. The 
commenter states that the parts manufacturer will be unable to provide 
an adequate number of parts to allow affected operators to meet the 
proposed compliance time of 18 months for replacement of GRAs on 
airplanes without an enhanced slat skew or loss detection system.
    We concur to extend the compliance time, but not necessarily for 
the reason stated by the commenter. We find that the 18-month 
compliance time for the required actions is necessary only for GRAs on 
slat number 2 outboard, slat number 9 outboard, slat number 4 inboard, 
and slat number 7 inboard on Boeing 757-200 series airplanes with line 
numbers 1 through 803, on which an enhanced slat skew or loss detection 
system has NOT been installed according to Boeing Service Bulletin 757-
27-0126, dated May 11, 2000, or Boeing Production Revision Record 
54755. For other slats on those airplanes, we find a 36-month 
compliance time (which is the compliance time for airplanes on which an 
enhanced slat skew or loss detection system has been installed) to be 
adequate. We have revised paragraphs (a)(1), (a)(2), (c)(1), and (c)(2) 
of this AD accordingly. This change to this AD will limit the number of 
replacement parts that will be needed within the 18-month compliance 
time, thus resolving the commenter's concern.

Request for Clarification of Parts Affected by This AD

    One commenter requests that we revise paragraph (b) of the proposed 
AD to clarify that no further action is required by this AD for any 
subject GRA that has been reworked and marked with ``SB27-21'' on the 
modification plate. The same commenter asks that we revise paragraph 
(c) of the proposed AD to state that further action is required for any 
subject part number that has NOT been previously reworked and marked 
with ``SB27-21'' on the modification plate. The commenter states that 
the wording of paragraphs (b) and (c) of the proposed AD suggest that 
GRAs with a part number series and serial number listed under Section 
1.A. of Hamilton Sundstrand Service Bulletins 5006397/755299-27-21 or 
5006398/755300-27-21, both dated January 24, 2000, cannot be installed 
on an airplane whether they have been reworked or not.
    Similarly, several other commenters request that we revise 
paragraph (d), the ``Spares'' paragraph, of the proposed AD, to allow 
use of affected GRAs, as long as the GRAs have a modification plate 
installed. These commenters note that the part number series and serial 
number of the parts will not be changed when they are reworked, but a 
modification plate will be installed on the reworked parts.
    We agree that some clarification of parts affected by this AD is 
necessary. We have confirmed with the parts supplier that, when the 
parts are reworked, the part number series and serial number are not 
necessarily changed, but the dash number for the service bulletin 
associated with the rework is stamped on the modification plate, which 
is installed on the part to the left of the data plate. In this case, 
the modification plate will be stamped with ``-21,'' if the part has 
been reworked per

[[Page 58923]]

Hamilton Sundstrand Service Bulletins 5006397/755299-27-21 or 5006398/
755300-27-21. Based on this information and the requests of the 
commenters, we have made the following changes to this final rule:
    <bullet> Paragraph (b) of this AD states that no further action is 
required by this AD if no GRA has a part number series and serial 
number listed under Section 1.A. of the Hamilton Sundstrand service 
bulletins, or if GRAs with a part number series and serial number 
listed under Section 1.A. of the referenced service bulletins have been 
reworked previously and the modification plates are marked with ``-
21.''
    <bullet> Paragraph (c) of this AD identifies parts subject to the 
actions in that paragraph as any GRA with a part number series and 
serial number listed under Section 1.A. of the referenced service 
bulletins that does not have a modification plate marked with ``-21.''
    <bullet> Paragraph (d) of this AD states that no one may install a 
GRA that has a part number series and serial number listed under 
Section 1.A. of Hamilton Sundstrand Service Bulletins 5006397/755299-
27-21 or 5006398/755300-27-21, on any airplane, unless the part has 
been reworked and the modification plate has been marked with ``-21.''

Request To Revise Language in Preamble

    One commenter requests that the FAA revise the section in the 
preamble of the proposed rule titled ``Explanation of Applicability.'' 
The commenter asks that we clarify that paragraph (d) of the proposed 
AD prohibits installation of NON-REWORKED affected parts after the 
effective date of this AD.
    We concur with the intent of the commenter's request. However, the 
section to which the commenter refers is not restated in this final 
rule, so no change is necessary in this regard.

Request To Revise Cost Impact Information

    One commenter states that it projects that a total of 90 work hours 
will be necessary to accomplish the proposed requirements, including 20 
work hours for the inspection, and 40 hours for replacement of the 
GRAs. The commenter also provides a summary of its costs associated 
with the proposed rule, based on actual direct costs associated with 
replacing all GRAs. Its estimates include time for testing and 
inspection of the installation of GRAs.
    The FAA does not concur that any change to the proposed rule is 
necessary in this regard. As stated in the proposed rule, the cost 
impact information in AD rulemaking actions typically includes only the 
``direct'' costs of the specific actions required by that AD. The 
number of work hours necessary to accomplish the required actions, 
specified in the cost impact information as 20 work hours for the 
inspection, and 30 work hours for replacement of the GRAs, if 
necessary, was provided to the FAA by the manufacturer based on the 
best data available to date. 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.

Explanation of Change to Proposed Rule

    The applicability statement of the proposed AD included ``Model 757 
series airplanes with a date of manufacture that is on or before the 
effective date of this AD.'' However, since the issuance of the 
proposed AD, we have determined that such an applicability may not 
ensure that a part subject to this AD is not installed in the future as 
a replacement part on airplanes manufactured after the effective date 
of this AD. Therefore, the applicability statement in this final rule 
has been revised to ``All Model 757 series airplanes.'' Because all 
Model 757 airplanes that are currently operating were included in the 
applicability of the proposed AD, we find that this change will not 
impose an additional burden on any operator and does not necessitate 
providing an additional opportunity for public comment.

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 950 Model 757 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 606 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 20 work hours per airplane to accomplish the 
required inspection, and that the average labor rate is $60 per work 
hour. Based on these figures, the cost impact of the AD on U.S. 
operators is estimated to be $727,200, or $1,200 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 replacement of all 
GRAs on an airplane, it will take approximately 30 work hours per 
airplane (1.5 work hours per actuator), at an average labor rate of $60 
per work hour. Required parts may be provided by the parts manufacturer 
at no cost to the operator. Based on these figures, the cost impact of 
the replacement is estimated to be up to $1,800 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.

[[Page 58924]]

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:

2001-23-14  Boeing: Amendment 39-12513. Docket 2000-NM-405-AD.

    Applicability: All Model 757 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 (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 prevent a fractured spring washer in a geared rotary actuator 
(GRA) for the leading edge slats, which could lead to a disconnect 
in the GRA, and result in a slat skew condition and consequent 
reduced controllability of the airplane, accomplish the following:

Inspection To Determine Serial Numbers

    (a) At the applicable compliance time specified in paragraph 
(a)(1) or (a)(2) of this AD, to determine the part number series and 
serial number for each GRA for the leading edge slats, review the 
maintenance records for the airplane, or inspect the 20 GRAs for the 
leading edge slats according to Boeing Alert Service Bulletin 757-
27A0133 (for Model 757-200, 757-200CB, and 757-200PF series 
airplanes), or 757-27A0134 (for Model 757-300 series airplanes), 
both dated October 11, 2000; as applicable.
    (1) For slat number 2 outboard, slat number 9 outboard, slat 
number 4 inboard, and slat number 7 inboard on Boeing 757-200 series 
airplanes with line numbers (L/N) 1 through 803, on which an 
enhanced slat skew or loss detection system has NOT been installed 
according to Boeing Service Bulletin 757-27-0126, dated May 11, 
2000, or Boeing Production Revision Record 54755: Do the review or 
inspection within 18 months after the effective date of this AD.
    (2) For slats other than those in the locations identified in 
paragraph (a)(1) of this AD, on the airplanes identified in 
paragraph (a)(1) of this AD, AND for all slats on airplanes other 
than those identified in paragraph (a)(1) of this AD: Do the review 
or inspection within 36 months after the effective date of this AD.

If No Subject GRA Is Installed--No Further Action

    (b) If no GRA has a part number series and serial number listed 
under Section 1.A. of Hamilton Sundstrand Service Bulletins 5006397/
755299-27-21 or 5006398/755300-27-21, both dated January 24, 2000; 
or if GRAs with a part number series and serial number listed in the 
referenced service bulletins have been reworked previously and the 
modification plates are marked with ``-21'': No further action is 
required by this AD.

If Any Subject GRAs Are Installed--Corrective Actions

    (c) For any GRA with a part number series and serial number 
listed under Section 1.A. of Hamilton Sundstrand Service Bulletins 
5006397/755299-27-21 or 5006398/755300-27-21, both dated January 24, 
2000, that does not have a modification plate marked with ``-21'': 
At the applicable compliance time specified in paragraph (c)(1) or 
(c)(2) of this AD, replace the subject GRA with a new or reworked 
GRA, according to Boeing Alert Service Bulletin 757-27A0133 (for 
Model 757-200, 757-200CB, and 757-200PF series airplanes), or 757-
27A0134 (for Model 757-300 series airplanes), both dated October 11, 
2000; as applicable.
    (1) For slat number 2 outboard, slat number 9 outboard, slat 
number 4 inboard, and slat number 7 inboard on Boeing Model 757-200 
series airplanes with L/N 1 through 803, on which an enhanced slat 
skew or loss detection system has NOT been installed according to 
Boeing Service Bulletin 757-27-0126, dated May 11, 2000, or Boeing 
Production Revision Record 54755: Replace any subject GRA within 18 
months after the effective date of this AD.
    (2) For slats other than those in the positions identified in 
paragraph (c)(1) of this AD, on the airplanes identified in 
paragraph (c)(1) of this AD, AND for all slats on airplanes other 
than those identified in paragraph (c)(1) of this AD: Replace any 
subject GRA within 36 months after the effective date of this AD.

Spares

    (d) After the effective date of this AD, no one may install a 
GRA that has a part number series and serial number listed under 
Section 1.A. of Hamilton Sundstrand Service Bulletins 5006397/
755299-27-21 or 5006398/755300-27-21, both dated January 24, 2000, 
on any airplane, unless the part has been reworked and the 
modification plate has been marked with ``-21.''

Alternative Methods of Compliance

    (e) 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 2: 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

    (f) 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

    (g) The actions shall be done in accordance with Boeing Alert 
Service Bulletin 757-27A0133, dated October 11, 2000; or Boeing 
Alert Service Bulletin 757-27A0134, dated October 11, 2000; as 
applicable. 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

    (h) This amendment becomes effective on December 31, 2001.


    Issued in Renton, Washington, on November 15, 2001.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-29186 Filed 11-23-01; 8:45 am]
BILLING CODE 4910-13-U

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