AD 2001-20-12

[Federal Register Volume 66, Number 200 (Tuesday, October 16, 2001)]
[Rules and Regulations]
[Pages 52492-52496]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-25617]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-225-AD; Amendment 39-12460; AD 2001-20-12]
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 
revising the Airworthiness Limitations Section of the maintenance 
manual (757 Airworthiness Limitations Instructions (ALI)). The revision 
will incorporate into the ALI certain inspections and compliance times 
to detect fatigue cracking of principal structural elements (PSE). This 
amendment is prompted by analysis of data that identified specific 
initial inspection thresholds and repetitive inspection intervals for 
certain PSEs to be added to the ALI. The actions specified by the 
proposed AD are intended to ensure that fatigue cracking of various 
PSEs is detected and corrected; such fatigue cracking could adversely 
affect the structural integrity of these airplanes.

DATES: Effective November 20, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 20, 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: Dennis Stremick, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, Washington; telephone (425) 227-2776; 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 January 29, 1999 (64 
FR 4367). That action proposed to require revising Section 9 of the 
Airworthiness Limitations Section of the maintenance manual (757 
Airworthiness Limitations Instructions (ALI)). The revision would 
incorporate certain inspections and compliance times to detect fatigue 
cracking of principal structural elements (PSE).

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 Notice of Proposed Rulemaking (NPRM)

    One commenter supports the NPRM.

1. Request for Specific Task Content and Implementation Intervals

    The manufacturer requests that a newer revision, dated November 
1998 of Boeing 757 Maintenance Planning Data, Boeing Document D622N001-
9, be specified in the final rule. The manufacturer notes that the 
November 1998 revision contains qualifying statements that, for some 
affected airplanes, would reduce the scope of some of the actions 
required by the May 1997 revision, which was cited in the NPRM as the 
appropriate source of service information. Another commenter states 
that it opposes the NPRM, but if the FAA issues the final rule, the 
operator requests that the identical task content and interval of 
implementation specified in Revision November 1998 of Boeing Document 
D622N001-9 be followed in the final rule.
    The FAA concurs that the final rule should specify more recent 
service information than the May 1997 revision. Since the issuance of 
the NPRM, Boeing Document D622N001-9 (Section 9), dated November 1998, 
has been issued by the manufacturer and approved by the FAA. We have, 
therefore, included the November 1998 revision as an option to 
accomplish in lieu of the May 1997 revision specified in paragraph (a) 
of this final rule. We consider the requirements of this final rule to 
be interim action until such time that a new NPRM may be developed to 
require accomplishment of the November 1998 revision of Boeing Document 
D622N001-9.

2. Request To Extend Reporting Requirement Period

    One commenter requests that the reporting period (as specified in 
Section 9) be extended from the proposed 10 days to 20 days. The 
commenter notes that 20 days would allow enough time to collate all 
inspection findings and transmit a single data package for each 
airplane.
    The FAA agrees with the commenter. However, since Section 9 is not 
specifically identified in the NPRM (it is embodied in the reference to 
Subsection B of Boeing Document D622N001-9), we have incorporated the 
reference to the reporting requirement that was specified in Note 2 of 
the NPRM into a new paragraph (b) of the final rule. Paragraph (b) of 
the final rule clarifies

[[Page 52493]]

that the reporting requirement embodied in the reference to Subsection 
B has been extended to within 20 days after performance of inspections 
required by paragraph (a) of the final rule.

3. Request To Provide Further Clarification Regarding Flight Cycles 
vs. Flight Hour Thresholds

    One commenter, the airplane manufacturer, states that, since there 
is reference to the 25,000-flight-cycle threshold and 50,000-flight-
cycle threshold in the preamble of the NPRM, it should also be noted 
that there is a flight cycle versus flight hour threshold for some 
items that are sensitive to flight length. Also, the commenter notes 
that there are some other restrictions, such as a calendar threshold of 
20 years unless an FAA-approved Corrosion Prevention and Control 
Program (CPCP) has been implemented, as well as a requirement to revert 
any escalated structural inspections back to the intervals specified in 
Section 8 of the Maintenance Planning Data (MPD) document.
    The FAA acknowledges that there is other information available in 
the revision to the MPD, which was not discussed in the preamble of the 
NPRM. The information that we provided in the preamble of the NPRM was 
intended to be representative of the information that was used to 
determine that none of the airplanes affected is likely to reach the 
threshold for certain PSEs, which are identified as Structurally 
Significant Items (SSIs) in the ALIs. Since the Discussion section in 
the preamble of the NPRM does not reappear in the final rule, no change 
to the final rule is necessary in this regard.

4. Request To Revise Certain Preamble Information

    One commenter, the manufacturer, notes that some necessary 
clarifications and corrections to information included under the 
heading ``Actions Taken by the Manufacturer'' in the preamble of the 
NPRM. The commenter advises that reference to the word ``recently'' is 
misleading since most of the listed actions occurred many years ago. 
The commenter also recommends listing the actions in order of 
significance and adding additional items to the actions specified under 
that heading.
    The FAA acknowledges that certain information under that heading 
could be revised for clarification purposes. However, since the 
information in the paragraph under that heading in the preamble of the 
NPRM does not reappear in the final rule, no change to the final rule 
is necessary in this regard.

5. Request To Revise Certain SSI Repair Actions

    One commenter requests that the proposed requirements of the NPRM 
be revised to reflect certain repair actions for SSIs that were 
installed before the effective date of the AD and certain other repair 
actions for SSIs that are installed after the effective date of the AD.
    The FAA does not agree. In the case of this final rule, the 
required action is simply to revise Section 9 of the Model 757 MPD by 
incorporating Subsection B of Boeing Document D622N001-9, Revision May 
1997 or November 1998. The specific information contained in the MPD is 
developed (with the concurrence of the FAA) and then printed by the 
manufacturer. We point out that the requirements of this AD do not 
address the accomplishment of the specific information contained in 
Subsection B. The effect of requiring that the MPD be revised to 
incorporate the current version of the ALI is that, in accordance with 
14 CFR Part 91.403(c), operators are then required to comply with 
limitations contained in the MPD. This is analogous to the effect of 
requiring a revision to the operating limitations. (In accordance with 
14 CFR Part 91.9(a), operators are required to comply with the revised 
operating limitations.) However, a new NOTE 1 has been added to the AD 
to address the possible need to obtain approval of alternative methods 
of compliance (AMOC) for certain repairs. Therefore, no further change 
to the final rule is necessary in this regard.

6. Request To Specify Proper MPD Subsection

    One commenter, the manufacturer, notes that the reference in the 
NPRM to ``Chapter B'' of Section 9 of Boeing 757 MPD is incorrect. The 
commenter states that the correct title is ``Subsection B.'' The FAA 
agrees and has revised the final rule accordingly.

7. Request To Withdraw the NPRM

    Several commenters state that the NPRM is unnecessary.
    One commenter states that the NPRM is unnecessary because Section 9 
of the MPD already mandates compliance with Airworthiness Certification 
Maintenance Requirements.
    Another commenter states that the NPRM is unnecessary as long as 
Boeing agrees to incorporate the changes on their own within the 
proposed three-year compliance time. The commenter states that issuing 
an AD to require the manufacturer to comply with a certain revision of 
its own manuals will only require more regulation down the road. The 
commenter explains that, when it is time to revise the MPD, an 
Alternate Means of Compliance (AMOC) would be required prior to using 
the new revision.
    Another commenter states that the rule is unnecessary because 
operators cannot revise a Boeing document.
    The FAA infers that, since these commenters state that they believe 
the NPRM is unnecessary, the commenters would like the NPRM to be 
withdrawn. We do not agree. The airworthiness limitations, like the 
operating limitations, are a part of the type certificate for an 
airplane. Once an airworthiness certificate is issued for an airplane 
certifying that it conforms to an approved type design, this design is 
``locked'' in the sense that the manufacturer cannot unilaterally 
change it for the subject airplane. Therefore, when the manufacturer 
makes any subsequent changes to the type certificate, including changes 
to the operating or airworthiness limitations, those changes are 
legally required only for products that are submitted for airworthiness 
certification based on a showing of conformity to the later design.
    Thus, for many years, the FAA has imposed operating restrictions 
that are necessary to address identified unsafe conditions by requiring 
revisions to the operating limitations section of the Airplane Flight 
Manual (AFM). (Revision of the AFM by the type certificate holder would 
be effective only for airplanes produced after that revision.) 
Similarly, Boeing's revision to the ALI was effective only for 
airplanes later certificated with those revisions included in their 
type certificate. For this reason, as stated in the NPRM, we must 
engage in rulemaking (i.e., issuance of an AD), in order to make the 
revisions mandatory for previously certificated airplanes.
    While the ALIs are contained in a ``Boeing document'' in the sense 
that Boeing originally produced it, the document, nevertheless, is a 
part of the instructions for continued airworthiness that operators 
must use to maintain the airplane properly. As explained in the NPRM, 
the effect of requiring that the document be revised to incorporate the 
current version of the ALI is that, in accordance with 14 CFR part 
91.403(c), operators are then required to comply with those 
limitations. This is analogous to the effect of requiring a revision to 
the operating limitations: in accordance with 14 CFR part 91.9(a), 
operators are required to comply with the revised operating 
limitations.
    Of course, those operators that have previously revised the ALI (or

[[Page 52494]]

incorporated the revision into their maintenance programs) are given 
credit for having previously accomplished the requirements of this AD, 
as allowed by the phrase, ``unless accomplished previously.'' The legal 
effect is the same: the operator is required to comply with the 
limitations per 14 CFR part 91.403(c).

8. Request To Clarify Intent of the NPRM

    One commenter states that paragraph (b) of the NPRM (paragraph (c) 
of the final rule) appears to conflict with the original intent of the 
NPRM. Paragraph (b) of the NPRM specifies that, after revising the MPD 
in accordance with paragraph (a) of the NPRM, no alternative 
inspections or inspection intervals shall be approved for the PSEs. The 
commenter explains that it is not clear why paragraph (b) is needed if 
the inspections were accomplished in accordance with 14 CFR parts 43 
and 91. The commenter states that paragraph (b) of the NPRM essentially 
defeats the stated purpose of the NPRM, which is to have operators 
record their AD compliance only once (at the time the operator's 
maintenance program is changed), in order to reduce the burden of 
record keeping and tracking.
    The FAA does not agree. The purpose of this AD is to address the 
identified unsafe condition of fatigue cracking in certain PSEs. We 
have determined that, in order to accomplish that purpose, those 
airplanes must be brought into compliance with the certification basis, 
i.e., 14 CFR Part 25.571, amendment 25-45. Revising the ALI, as 
required by paragraph (a) of this AD, fulfills this purpose. Once an 
operator records that the ALI have been revised, additional record 
keeping of AD compliance is not required, since the actual 
accomplishment of the inspections specified in the ALI is required, not 
by the AD, but by 14 CFR 91.403(c). We point out that paragraph (c) of 
the final rule merely repeats and enforces the provision presently 
existing in the Boeing 757 MPD, which requires any revision of the 
airworthiness limitations to be approved by the Manager, Seattle 
Aircraft Certification Office, FAA. We consider that paragraph (c) of 
the final rule, therefore, does not conflict with the intention to have 
operators record their AD compliance only once. No change is necessary 
to the final rule in this regard.

9. Request To Permit Compliance With Damage Tolerance Rating (DTR) 
System

    One commenter requests that paragraph (b) of the NPRM be revised to 
permit compliance with the DTR system. The commenter states that the 
supplemental inspection program uses the DTR system to determine the 
inspections/inspection intervals necessary to provide adequate fatigue 
damage detection for each SSI. The commenter notes that the DTR check 
forms define inspection options permitting an operator to customize an 
inspection program.
    The FAA does not agree that a revision is necessary. The DTR system 
is specifically referenced in the ALI, and its use is allowed by 
paragraph (a) of this AD. Therefore, there is no need to obtain a 
separate approval for its use. This AD does not specifically address 
(or restrict) the use of the DTR specified in the ALI. No change is 
necessary to the final rule in this regard.

10. Requests To Require Incorporation of ALI Into Operations 
Specifications

    One commenter, the manufacturer, suggests that the NPRM be revised 
to require the operators to incorporate the ALIs into the appropriate 
Maintenance Program Specification (Operations Specification).
    The FAA does not agree that incorporation of the ALIs into the 
Operations Specifications (Ops Specs) is appropriate. Operation of 
certain transport airplanes may be exclusively under the provisions and 
requirements of part 91, and therefore, operators would not even be 
required to maintain Ops Specs. Further, Ops Specs simply authorize the 
use of a Continuous Airworthiness Maintenance Program (CAMP) for the 
operator's individual airplane models and specify, in particular, that 
procedures, standards, checks, service, repair, and/or preventive 
maintenance, and tests, shall be described in the certificate holder's 
manual.
    The commenter further requests that the requirements of the NPRM be 
written such that the operator's Ops Specs is continuously updated with 
the current revision of Section 9 of the MPD. If that process is not 
possible, the commenter suggests that the requirements be accomplished 
in accordance with the latest FAA-approved revision of Section 9 of the 
MPD.
    The FAA does not agree with the commenter's requests. We note that 
the commenter provided no justification or benefit of implementing the 
suggested changes. In response to the suggestion that the Ops Specs be 
continuously updated with current revisions of Section 9 of the MPD, we 
note that incorporation of new revisions of the ALI into the Ops Specs 
would have the effect of imposing new requirements without providing 
notice to the public and opportunity for comment.
    However, in this case, the request to reference a specific later 
revision is acceptable as an alternative method of compliance, as 
explained previously in comment number 1. of this final rule. 
Therefore, we have revised paragraph (a) of the final rule to add the 
``November 1998'' revision of Section 9 of the MPD as an optional or 
alternative method of compliance with the requirements of this AD.

11. Request To Omit Apostrophe in Acronyms

    The manufacturer requests that the apostrophe be deleted on plural 
use of acronyms, e.g., PSEs and ADs. The FAA acknowledges that there 
are different applications of the use of apostrophes for plural 
acronyms. For the purpose of consistency in this AD, we have revised 
all plural acronyms to omit the apostrophe.

Editorial Changes Appearing in the Final Rule

    We have revised the contents of Note 1 of the final rule to clarify 
for operators the intent and purposes of that note when performing 
inspections in accordance with certain airworthiness limitations 
documents.
    We also note that, while SSIs are a subset of PSEs, the Federal 
Aviation Regulations (FAR) related to damage tolerance refer only to 
PSEs. Therefore, for the purposes of this AD, we consider the two terms 
interchangeable. A new NOTE 2 has been added to the final rule to 
clarify this information.

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 764 Boeing Model 757 series airplanes of 
the affected design in the worldwide fleet. The FAA estimates that 300 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 1 work hour 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 the AD on U.S. operators is estimated 
to be $18,000, or $60 per airplane.

[[Page 52495]]

    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.
    Although this AD requires only a revision to the current ALI, the 
FAA recognizes that the inspections contained in the ALI will then be 
required by parts 43 and 91 of the FAR. The FAA estimates that it will 
take approximately 1,000 work hours to accomplish all of the ALI 
inspections. At an average labor rate of $60 per work hour, the cost to 
perform the ALI inspections (required by FAR parts 43 and 91, rather 
than by part 39) will be approximately $60,000 per airplane. The FAA 
notes that the majority of work hours needed to perform the inspections 
will be expended when an affected airplane reaches the 50,000-flight-
cycle threshold. Based upon current airplane utilization, the FAA 
estimates that no airplane will reach this threshold for at least 10 
years.

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:

2001-20-12  Boeing: Amendment 39-12460. Docket 98-NM-225-AD.

    Applicability: Model 757 series airplanes having line numbers 1 
through 764 inclusive, certificated in any category.

    Note 1: This AD requires revisions to certain operator 
maintenance documents to include new inspections. Compliance with 
these inspections is required by 14 CFR Part 91.403(c). For 
airplanes that have been previously modified, altered, or repaired 
in the areas addressed by these inspections, the operator may not be 
able to accomplish the inspections described in the revisions. In 
this situation, to comply with 14 CFR part 91.403(c), the operator 
must request approval for an alternative method of compliance in 
accordance with paragraph (d) of this AD. The request should include 
a description of the changes to the required inspections that will 
ensure the continued damage tolerance of the affected structure. The 
FAA has provided guidance for this determination in Advisory 
Circular (AC) 25-1529.

    Compliance: Required as indicated, unless accomplished 
previously.
    To ensure continued structural integrity of these airplanes, 
accomplish the following:

Revision of Airworthiness Limitations and Certification Maintenance 
Requirements

    (a) Within 3 years after the effective date of this AD, revise 
Section 9 of the Boeing 757 Maintenance Planning Data (MPD) Document 
entitled ``Airworthiness Limitations and Certification Maintenance 
Requirements (CMRs)'' to incorporate Subsection B. of Boeing 
Document D622N001-9, Revision ``May 1997,'' or Revision ``November 
1998.''

    Note 2: For the purposes of this AD, the terms Principal 
Structural Elements (PSEs) as used in this AD, and Structural 
Significant Items (SSIs) as used in Section 9 of Boeing 757 MPD 
Document, are considered to be interchangeable.

Reporting Requirements

    (b) Although Subsection B. of Boeing Document D622N001-9, dated 
November 1998, references a requirement that cracks found during the 
specified inspections be reported with 10 days, this AD requires 
that those reports be submitted to the Seattle Aircraft 
Certification Office (ACO), FAA, Transport Airplane Directorate, 
within 20 days after the inspection. Information collection 
requirements contained in this regulation have been approved by the 
Office of Management and Budget under the provisions of the 
Paperwork Reduction Act of 1980 (44 U.S.C. 3501, et seq.) and have 
been assigned OMB Control Number 2120-0056.

Alternative Methods of Compliance

    (c) Except as provided in paragraph (d) of this AD: After the 
actions required by paragraph (a) of this AD have been accomplished, 
no alternative inspections or inspection intervals shall be approved 
for the PSEs contained in Boeing Document D622N001-9, Revision ``May 
1997'' or ``November 1998.''
    (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 ACO. 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 
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

    (f) The MPD revision shall be done in accordance with Boeing 757 
Maintenance Planning Data Document, Section 9, Boeing Document 
D622N001-9, Revision ``MAY 1997;'' or Boeing 757 Maintenance 
Planning Data Document, Section 9, Boeing Document D622N001-9, 
Revision ``November 1998.'' Boeing 757 Maintenance Planning Data 
Document, Section 9, Boeing Document D622N001-9, Revision ``MAY 
1997'' contains the following effective pages:

------------------------------------------------------------------------
                Page No.                     Revision  shown  on page
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List of Effective Pages--Page 9.0-4....  May 1997.
------------------------------------------------------------------------

Boeing 757 Maintenance Planning Data Document, Section 9, Boeing 
Document D622N001-9, Revision ``November 1998'' contains the 
following effective pages:

------------------------------------------------------------------------
                Page No.                     Revision  shown  on page
------------------------------------------------------------------------
List of Effective Pages--Page 9.0-5....  November 1998.
------------------------------------------------------------------------


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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

    (g) This amendment becomes effective on November 20, 2001.

    Issued in Renton, Washington, on October 4, 2001.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-25617 Filed 10-15-01; 8:45 am]
BILLING CODE 4910-13-P