[Federal Register Volume 59, Number 60 (Tuesday, March 29, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-7319]


[[Page Unknown]]

[Federal Register: March 29, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 93-NM-72-AD; Amendment 39-8866; AD 94-07-08]

 

Airworthiness Directives; Boeing Model 727 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 727 series airplanes, that requires 
structural inspections of older airplanes. This amendment is prompted 
by reports of incidents involving fatigue cracking and corrosion in 
transport category airplanes that are approaching or have exceeded 
their economic design service goal. The actions specified by this AD 
are intended to prevent degradation of the structural capabilities of 
the affected airplanes. This proposal relates to the recommendations of 
the Airworthiness Assurance Task Force assigned to review Model 727 
series airplanes, which indicate that, to assure long term continued 
operational safety, various structural inspections should be 
accomplished.

DATES: Effective April 28, 1994.
    The incorporation by reference of Boeing Document Number D6-54860, 
``Aging Airplane Service Bulletin Structural Modification and 
Inspection Program - Model 727,'' Revision G, dated March 5, 1993, 
listed in the regulations was approved previously by the Director of 
the Federal Register as of April 21, 1994 (59 FR 13442, March 22, 
1994).

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: Walter Sippel, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (206) 227-2774; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations to include an airworthiness directive (AD) that is 
applicable to certain Boeing Model 727 series airplanes was published 
in the Federal Register on August 31, 1993 (58 FR 45863). That action 
proposed to require structural inspections of older airplanes.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter supports the proposed rule.
    Two commenters note errors in the Discussion section of the 
proposal in the description of Boeing Document Number D6-54860, ``Aging 
Airplane Service Bulletin Structural Modification and Inspection 
Program - Model 727,'' Revision G, dated March 5, 1993. Although the 
Discussion section does not reappear in the preamble to the final rule, 
the FAA takes this opportunity to correct the number of service 
bulletins referenced by the Boeing Document. There is a total of 17 
service bulletins referenced by the Boeing Document: five service 
bulletins that describe inspections of the wings, six service bulletins 
that describe inspections of the fuselage, one service bulletin that 
describes inspections of the main landing gear door support fitting, 
four service bulletins that describe inspections of the empennage, and 
one service bulletin that describes inspections of the attach fittings 
on the center engine inlet duct housing.
    One commenter requests that the FAA issue one rulemaking action 
that would combine the requirements of this proposal, which proposes to 
require the structural inspections listed in the Boeing Document, with 
the proposal to require the structural modifications listed in that 
Boeing Document. That rulemaking action was proposed in AD Docket 93-
NM-73-AD (58 FR 45861, August 31, 1993). This commenter requests that 
these two rulemaking actions be combined with AD 90-06-09, Amendment 
39-6488 (55 FR 8370, March 7, 1990), which references Revision C of the 
Boeing Document, dated December 11, 1989. Combining all of these 
actions into one AD would ease the operators' burden in tracking 
compliance and recordkeeping.
    The FAA does not concur. The FAA's normal policy in this regard is 
that when an AD requires a substantive change, such as a change in the 
existing AD's requirements, the existing AD (90-06-09) is superseded by 
being removed from the system and a new AD added. However, to supersede 
the existing AD and replace it with a new one having a new AD number 
would serve no purpose in terms of the ability of affected operators to 
track compliance with the AD and maintain accurate records of 
compliance. In consideration of the consequent workload associated with 
revising maintenance records to enter new AD numbers to demonstrate 
compliance with requirements accomplished previously, the FAA has 
determined that a less burdensome approach is to issue a separate AD. 
This final rule is issued as a separate AD action since combining these 
rulemaking actions would necessitate recordkeeping changes to reflect 
new AD numbers. Furthermore, the FAA's intent in keeping the 
requirement to accomplish the inspections listed in the Boeing Document 
separated from the requirement to accomplish the modifications listed 
in the Boeing Document was to minimize the recordkeeping burden to the 
operators; i.e., operators will not be required to make recordkeeping 
changes to their inspection entries whenever revisions are made to 
modification requirements and vice versa.
    One commenter requests that the proposed compliance time for the 
repetitive inspections in paragraph (a) be revised to be consistent 
with those recommended in the Boeing Document. The FAA does not concur 
that any change is necessary. From this comment, the FAA concludes that 
this commenter may have mistakenly assumed that the proposal would have 
required that the repetitive inspections must be accomplished at the 
times specified in the corresponding service bulletins. Consequently, 
paragraph (a) of the final rule remains unchanged and states that 
repetitive inspections are to be accomplished ``thereafter at intervals 
not to exceed those specified in the Boeing Document for each 
inspection.'' Furthermore, since the corresponding service bulletins 
have been revised to be consistent with the Boeing Document, the 
compliance times for the repetitive inspections are consistently 
defined in the final rule, the Boeing Document, and the corresponding 
service bulletins.
    Several commenters request that proposed paragraphs (a) and (b) be 
revised to clarify that only the structural inspections listed in 
section 4 and appendices A.4 and B.4 of the Boeing Document must be 
accomplished. Since the proposal stated that the inspections were 
specified in ``section 4 and appendices A. and B.'' of the Boeing 
Document, these commenters contend that the possibility exists for 
misinterpretation. The FAA concurs. The FAA finds that these 
commenters' proposal to reference the specific appendices of the Boeing 
Document (rather than the generalization cited in the proposal) would 
avoid any possibility for misinterpretation. Therefore, paragraphs (a) 
and (b) of the final rule have been revised accordingly.
    The Air Transport Association of America, on behalf of one of its 
member operators, requests that the note following proposed paragraph 
(b)(2) be clarified. The commenter states that the term ``phase-in 
period'' was not adequately defined in the proposal and that it was not 
used in the Boeing Document, which was referenced in the proposal. 
Since some of the service bulletins that are referenced by the Boeing 
Document specify a ``phase-in'' time, while others do not, the 
commenter further requests that issuance of the final rule be delayed 
until such time that the 727 Structures Working Group of the 
Airworthiness Assurance Task Force has reconvened to resolve this 
issue. The FAA concurs that clarification is warranted; however, the 
FAA does not concur that delaying issuance of the final rule is 
necessary, since the following discussion, as well as the revised final 
rule, adequately defines ``phase-in period.'' The FAA's intent in using 
the term ``phase-in period'' was to grant a ``grace period'' of 15 
months to operators having airplanes that will soon exceed or that have 
already exceeded the threshold specified in the Boeing Document.
    In light of this comment, the FAA has revised paragraph (b) of the 
final rule to clarify that, in those instances when a ``phase-in 
period'' is specified in any of the service bulletins referenced by the 
Boeing Document, the maximum initial inspection time is to be 
calculated using the ``phase-in period'' specified in the service 
bulletin and adding a date 15 months after the effective date of the 
AD. An example of this, although not specifically referred to as a 
``phase-in period'', can be found in the Accomplishment Instructions of 
Boeing Service Bulletin 727-53-0041, Revision 6, dated September 5, 
1991, which states, in part, that ``airplanes having accumulated more 
than 16,000 flight cycles should be inspected within 3,000 flight 
cycles . . .'' The ``phase-in period'' in this example is ``within 
3,000 flight cycles.'' Therefore, for the purposes of this AD, the 
maximum initial inspection time in this instance is 3,000 flight cycles 
measured from a date 15 months after the effective date of this AD.
    However, in those instances when a ``phase-in period'' is not 
specified in any of the service bulletins referenced by the Boeing 
Document, the FAA's intent is to allow operators 15 months for planning 
purposes. In these instances, the maximum initial inspection time is 15 
months after the effective date of this AD.
    One commenter requests that the proposal be revised to permit 
deviations to the corrective actions required by proposed paragraph 
(c), and suggests that these be permitted to be accomplished in 
accordance with other FAA-approved methods, e.g., Structural Repair 
Manuals; Statement of Compliance with the Federal Aviation Regulations, 
FAA Form 8110-3; etc. The commenter's intent for requesting this change 
is to gain authorization to make minor deviations, such as oversizing 
fasteners and substituting materials, without obtaining approval for an 
alternative method of compliance for each deviation. The commenter 
states that safety could be ensured with repetitive inspections until 
such time that the corrective action specified in the corresponding 
service bulletin referenced by the Boeing Document could be 
accomplished during regularly scheduled maintenance, so as to minimize 
the impact to operators' revenue bearing passenger service. The FAA 
does not concur. The FAA has determined that the Manager, Seattle 
Aircraft Certification Office, should approve any such deviations to 
the AD's requirements. Given that possible new relevant issues might be 
revealed during this process, it is imperative that the FAA, at this 
level, have such feedback. Only by reviewing deviation approvals can 
the FAA be assured of this feedback and of the adequacy of the repair 
methods. However, when the FAA has obtained an adequate sampling of the 
quality, type, and extent of repairs being made as a result of this AD, 
the FAA anticipates that it will, at some future date, authorize 
manufacturer's Designated Engineering Representatives to approve minor 
deviations to the modifications required by this final rule, as it has 
done in the past regarding the requirements of AD 90-06-09, and other 
aging fleet AD's. Furthermore, affected operators may request approval 
to use an alternative method of compliance to the corrective actions 
specified in the corresponding service bulletins, under the provisions 
of paragraph (e) of the final rule.
    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.
    There are approximately 1,635 Model 727 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 688 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 512 work hours per airplane to accomplish the 
required actions, and that the average labor rate is $55 per work hour. 
Based on these figures, the total cost impact of the AD on U.S. 
operators is estimated to be $19,374,080, or $28,160 per airplane.
    The total 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 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 14 CFR part 
39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

94-07-08 Boeing: Amendment 39-8866. Docket 93-NM-72-AD.

    Applicability: Model 727 series airplanes, as listed in Boeing 
Document D6-54860, ``Aging Airplane Service Bulletin Structural 
Modification and Inspection Program--Model 727,'' Revision G, dated 
March 5, 1993; certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent degradation of the structural capability of the 
airplane, accomplish the following:
    (a) Accomplish the inspections specified in Section 4 and 
Appendices A.4 and B.4 of Boeing Document Number D6-54860, ``Aging 
Airplane Service Bulletin Structural Modification and Inspection 
Program--Model 727,'' Revision G, dated March 5, 1993, within the 
times specified in paragraph (b) of this AD, and thereafter at 
intervals not to exceed those specified in the Boeing Document for 
each inspection.
    (b) The maximum initial inspection times for the inspections 
contained in Section 4 and Appendices A.4 and B.4 of Boeing Document 
Number D6-54860, ``Aging Airplane Service Bulletin Structural 
Modification and Inspection Program--Model 727,'' Revision G, dated 
March 5, 1993, shall be prior to the later of the times specified in 
either paragraph (b)(1) or (b)(2) of this AD:
    (1) The maximum initial inspection time for the inspection shall 
be prior to the threshold for the inspection time specified in the 
Boeing Document, measured as a total (flight cycles or time-in-
service, as appropriate) accumulated on the airplane; or
    (2) The maximum initial inspection time shall be prior to the 
time specified in either paragraph (b)(2)(i) or (b)(2)(ii) of this 
AD, as applicable.
    (i) If a phase-in period has been specified in the service 
bulletin: The maximum initial inspection time shall be calculated by 
adding the phase-in period for the inspection specified in the 
Boeing Document to a date 15 months after the effective date of this 
AD.
    (ii) If a phase-in period has not been specified in the service 
bulletin: The maximum initial inspection time shall be within 15 
months after the effective date of this AD.

    Note 1: For the purposes of this AD, the ``phase-in period'' is 
defined as the allowable period to accomplish the initial inspection 
when the required threshold specified in paragraph (b)(1) of this AD 
is imminent or has elapsed.

    (c) If any discrepant condition identified in the service 
bulletins (that are specified in the Boeing Document) is found as a 
result of the inspections required by this AD, prior to further 
flight, accomplish the corresponding corrective action specified in 
the service bulletins.
    (d) The terminating action for each inspection required by 
paragraph (a) of this AD consists of the accomplishment of the 
modification specified in the corresponding service bulletin.
    (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, 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (f) Special flight permits may be issued in accordance with 
Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the 
airplane to a location where the requirements of this AD can be 
accomplished.
    (g) The inspections shall be done in accordance with Boeing 
Document Number D6-54860, ``Aging Airplane Service Bulletin 
Structural Modification and Inspection Program--Model 727,'' 
Revision G, dated March 5, 1993. The incorporation by reference of 
this document was approved previously by the Director of the Federal 
Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51 as of 
April 21, 1994 (59 FR 13442, April 22, 1994). 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.
    (h) This amendment becomes effective on April 28, 1994.

    Issued in Renton, Washington, on March 23, 1994.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-7319 Filed 3-28-94; 8:45 am]
BILLING CODE 4910-13-U