[Federal Register Volume 65, Number 70 (Tuesday, April 11, 2000)]
[Rules and Regulations]
[Pages 19310-19313]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-8516]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-53-AD; Amendment 39-11666; AD 2000-07-12]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 727 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 727 series airplanes, that requires 
repetitive structural inspections of certain aging airplanes, and 
repair, if necessary. This amendment also provides for optional 
terminating action for the repetitive inspections. 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 AD 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 May 16, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 16, 2000.

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 FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington. 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 (425) 227-2774; 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 727 series 
airplanes was published in the Federal Register on June 25, 1999 (64 FR 
34168). That action proposed to require repetitive structural 
inspections of certain aging airplanes, and repair, if necessary.

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

    The Air Transport Association (ATA) of America, on behalf of three 
of its members, indicates that these members generally support the 
proposal. One of those members states that it does not operate any 
Boeing Model 727-200 series airplanes, line numbers 1 through 1214; 
another member has no objections to the proposed rule; and another 
member has no objection to the intent of the proposed rule but proposes 
certain clarifications.

Requests To Correct References

    Two commenters state that a number of incorrect references are 
cited in the proposed AD. The commenters recommend changing references 
from ``AD 94-05-04'' to ``AD 90-06-09'' in the ``Other Relevant 
Rulemaking'' and ``Differences Between Proposed Rule and Service 
Bulletin'' sections of the proposed AD, the applicability of the 
proposed AD, and paragraph (d) of the proposed AD [cited as paragraphs 
(g)(1) and (g)(2) in the final rule]. One of the commenters contends 
that Revision 3 of Boeing Service Bulletin 727-57-0127, dated August 
24, 1989 (which is referenced in Boeing Document Number D6-54860), 
clearly references repetitive inspections at intervals of 14,000 flight 
cycles. However, the Boeing document only specifies an inspection in 
accordance with Note 2 of Revision 3 of the service bulletin, and Note 
2 does not refer to the repetitive inspections. Another of the 
commenters contends that Revision 2 of the service bulletin, dated 
February 13, 1976, was cited in the Boeing document and was mandated by 
AD 94-07-08.
    Although the ``Other Relevant Rulemaking'' and ``Differences'' 
sections are not included in the final rule, the FAA concurs that it is 
necessary to change all references from ``AD 94-05-04'' to ``AD 90-06-
09'' because the proposed AD incorrectly referenced AD 94-05-04. 
However, with regard to the correct revision number of the service 
bulletin, the FAA points out that AD 94-07-08 specifies Revision 3 
rather than Revision 2 of the service bulletin, and that Revision 2 of 
the service bulletin is relevant to AD 90-06-09. To clarify the 
applicability of the final rule,

[[Page 19311]]

the FAA has changed the AD reference, and clarified that the actions 
are to be accomplished for certain airplanes on which the modification 
specified by either Revision 2 or Revision 3 of the service bulletin 
has not been accomplished. In addition, the AD references are changed 
in paragraphs (g)(1) and (g)(2) of the final rule.

Request To Extend Compliance Time for Initial Inspection

    The commenter states that the compliance time in paragraph (a) of 
the proposed AD should be extended. That compliance time assumes that 
all Model 727 series airplanes have exceeded the initial inspection 
threshold, as it requires the initial inspection within 2,000 flight 
cycles [a phase-in (grace) period] after the effective date of the AD. 
The commenter points out that Note 2 in Part III of the Accomplishment 
Instructions of Boeing Service Bulletin 727-57-0127, Revision 3, 
specifies a threshold of 16,000 flight cycles and a phase-in period if 
an airplane has exceeded that threshold. The commenter has reviewed the 
active fleet of Model 727 series airplanes and has found that, at the 
present time, there are 36 airplanes that have accumulated less than 
14,000 total flight cycles. The commenter also states that if the 
initial inspection has been accomplished in accordance with AD 94-07-
08, that AD also requires repetitive inspection intervals of 14,000 
total flight cycles. Therefore, the commenter recommends extending the 
compliance time in paragraph (a) of the proposed AD.
    The FAA concurs that the compliance time should be extended, and 
that whether the initial inspection has or has not been accomplished in 
accordance with AD 94-07-08 should be considered. Therefore, paragraph 
(a) of the final rule has been revised to specify the inspection 
requirements for those airplanes on which the initial inspection has 
not been accomplished in accordance with AD 94-07-08, and a new 
paragraph (b) has been added to specify the inspection requirements for 
those airplanes on which the initial inspection has been accomplished 
in accordance with AD 94-07-08. [Paragraphs (a)(1) and (a)(2) of the 
proposed AD have been renumbered as paragraphs (c) and (d) in the final 
rule.]

Request To Clarify Type of Inspection

    One commenter states that although the proposed AD requires a ``dye 
penetrant inspection,'' Revision 3 of the Boeing service bulletin only 
specifies a ``penetrant inspection,'' and does not reference a Boeing 
process specification, Non-Destructive Test manual reference, or any 
other kind of reference as to the type of penetrant inspection (e.g., 
dye or fluorescent) that should be performed.
    The FAA acknowledges that clarification of the type of inspection 
is necessary. Paragraph (a)(1) of the proposed rule specifies a ``dye 
penetrant inspection'' in accordance with Boeing Service Bulletin 727-
57-0127, Revision 3, and Boeing Standard Overhaul Practices Manual D6-
51702, Chapter 20-20-02, Revision 79, dated March 1, 1999. Although the 
service bulletin specifies a ``penetrant inspection,'' Figure 1 of the 
Standard Overhaul Practices Manual specifies a ``fluorescent dye 
penetrant inspection (Type I).'' Based on the type of inspection 
included in the manual, the FAA has clarified the type of inspection 
specified in the preamble and paragraph (c) of the final rule.

Request To Clarify Terminating Action Required by AD 94-07-08

    One commenter states that operators have expressed concerns that 
another AD is being written to mandate the inspections required by 
Boeing Service Bulletin 727-57-0127 [Revision 3], when AD 94-07-08 
currently mandates such inspections. However, the proposed AD does not 
state that it will supersede the inspection requirements of Service 
Bulletin 727-57-0127, as mandated by AD 94-07-08. Therefore, the 
commenter recommends adding a note to the proposed AD stating that 
``Upon incorporation of the requirements of this AD, the inspection 
requirements of Boeing Service Bulletin 727-57-0127 mandated by AD 94-
07-08 may be deleted.''
    The FAA acknowledges the concern expressed by the commenter that 
the proposed AD requires inspections currently required by paragraph 
(a) of AD 94-07-08. In response, the FAA has clarified in paragraph 
(g)(1) of the final rule that accomplishment of the inspections 
required by this AD constitutes terminating action for the inspections 
required by paragraph (a) of AD 94-07-08, as specified in Boeing 
Service Bulletin 727-57-0127, Revision 3.

Request To Delete Reference to Corrosion

    One commenter states that, although the summary of the proposed AD 
states that the AD was prompted by reports of incidents involving 
fatigue cracking and corrosion found on older airplane models, Boeing 
Service Bulletin 727-57-0127 only addresses fatigue cracking and does 
not address corrosion. The FAA infers that the commenter suggests 
deleting the reference to corrosion in the summary of the proposed 
rule.
    The FAA does not concur. Although the service bulletin does not 
include a reference to corrosion and only includes a reference to 
fatigue cracking, the FAA points out that the Working Group's reference 
to Boeing Document Number D6-54860, ``Aging Airplane Service Bulletin 
Structural Modification Program--Model 727,'' Revision C, dated 
December 11, 1989 (as cited in the Discussion paragraph of the proposed 
AD), was established to address problems associated with both fatigue 
cracking and corrosion. In light of this, the FAA considers that the 
reference to corrosion is appropriate, and no change to the final rule 
is necessary in this regard.

Request To Clarify Inspection Requirement for Airplanes in Groups 4 
and 5

    One commenter recommends revising ``Other Relevant Rulemaking'' in 
the proposed AD to clarify that AD 94-07-08 inadvertently omitted the 
requirement to mandate repetitive inspections for certain wing ribs on 
airplanes in groups 4 and 5, because Section 4 of Boeing Document 
Number D6-54860 references Revision 2 of Boeing Service Bulletin 727-
57-0127. The commenter adds that Revision 3 of the service bulletin 
specifies an additional rib inspection for airplanes in groups 4 and 5 
only, and no additional requirements for airplanes in groups 1, 2, 3, 
and 6.
    Although ``Other Relevant Rulemaking'' is not included in the final 
rule, the FAA acknowledges that AD 94-07-08 inadvertently omitted a 
requirement for the repetitive inspections. However, the FAA points out 
that the commenter was mistaken in stating that Boeing Document Number 
D6-54860, references Revision 3 (rather than Revision 2) of the service 
bulletin. In addition, Revision 3 of the service bulletin does include 
the additional rib inspection for airplanes in groups 4 and 5. 
Therefore, no change to the final rule is necessary in this regard.

Request To Allow Later Revisions of Service Bulletins

    One commenter states that, in the ``Initial Inspection'' section of 
the NPRM, the reference documents for accomplishing the dye penetrant 
and high frequency eddy current inspections include a specific revision 
number for the service bulletin. The commenter suggests adding ``or 
later revisions'' so that when future revisions are released, there 
will not be any confusion as to which revision to use.

[[Page 19312]]

    The FAA does not concur with the request to revise the AD to 
reference later revisions of the service bulletin, because it cannot 
approve the use of a document that does not yet exist. In addition, 
when a service bulletin is referenced in an AD, the use of the phrase, 
``or later FAA-approved revisions,'' violates Office of the Federal 
Register regulations regarding approval of materials that are 
incorporated by reference. Therefore, the FAA has determined that it is 
necessary to specify a certain revision number for all service 
bulletins specified in the final rule. However, the FAA points out that 
operators may submit any requests to use a later service bulletin 
through an appropriate FAA Principal Maintenance Inspector, as provided 
for by paragraph (h) of this AD.

Request To Revise Inspection Intervals

    One commenter recommends extending the inspection intervals in 
paragraph (b) of the proposed AD to give credit for the accomplishment 
of initial or previous inspections in accordance with AD 94-07-08, and 
basing the next required inspection interval on the date the previous 
inspection was accomplished.
    The FAA does not concur that it is necessary to revise the 
inspection intervals required by paragraph (b) of the proposed AD 
[cited as paragraph (e) of the final rule] because paragraph (a) of the 
proposed AD [cited as paragraph (b) of the final rule] states that the 
initial inspection is required within 2,000 flight cycles after the 
effective date of this AD, ``unless accomplished within the last 12,000 
flight cycles in accordance with AD 94-07-08.'' Therefore, the proposed 
AD provides credit for a previous inspection that was accomplished 
within 12,000 flight cycles; as a result, the proposed AD allows 
operators to repeat the inspection within 14,000 flight cycles after 
the last inspection. No change to the final rule is necessary in this 
regard.

Explanation of Change Made to the Proposal

    The FAA has revised paragraph (c) of the proposed rule that 
requires repair in accordance with Boeing Service Bulletin 727-57-0127, 
Revision 3. That paragraph, renumbered as paragraph (f) in the final 
rule, adds that repair also may be accomplished in accordance with a 
method approved by the FAA; or in accordance with data meeting the type 
certification basis of the airplane approved by a Boeing Company 
Designated Engineering Representative who has been authorized by the 
FAA to make such findings.

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 975 Model 727 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 538 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 300 work hours per airplane to accomplish the 
required inspections, and that the average labor rate is $60 per work 
hour. Based on these figures, the cost impact of the inspections 
required by this AD on U.S. operators is estimated to be $9,684,000, or 
$18,000 per airplane, per inspection cycle.
    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.
    Should an operator elect to accomplish the optional terminating 
action rather than continue the repetitive inspections, it would take 
approximately 900 work hours per airplane to accomplish the 
modification, at an average labor rate of $60 per work hour. Required 
parts will cost approximately $31,144 per airplane. Based on these 
figures, the cost impact of this optional terminating action is 
estimated to be $85,144 per airplane.

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 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:

2000-07-12  Boeing: Amendment 39-11666. Docket 99-NM-53-AD.

    Applicability: Model 727-100, -100C, and -200 series airplanes, 
line numbers 1 through 1214 inclusive; certificated in any category; 
except those on which the modification specified by either Boeing 
Service Bulletin 727-57-0127, Revision 2, dated February 13, 1976, 
or Boeing Service Bulletin 727-57-0127, Revision 3, dated August 24, 
1989, has been installed.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 (h) 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 degradation of the structural capabilities of the 
affected airplanes, accomplish the following:

Initial Inspection

    (a) For those airplanes on which the initial inspection has not 
been accomplished in accordance with AD 94-07-08, amendment

[[Page 19313]]

39-8866: Prior to the accumulation of 16,000 total flight cycles or 
within 2,000 flight cycles after the effective date of this AD, 
whichever occurs later, accomplish the inspections required by 
either paragraph (c) or (d) of this AD.
    (b) For those airplanes on which the initial inspection has been 
accomplished in accordance with AD 94-07-08, amendment 39-8866: 
Within 2,000 flight cycles after the effective date of this AD, 
unless accomplished within the last 12,000 flight cycles in 
accordance with AD 94-07-08, accomplish the inspections required by 
either paragraph (c) or (d) of this AD.
    (c) Perform a fluorescent dye penetrant inspection (Type I) to 
detect cracking of certain wing ribs at the rib-to-stringer 
attachment in the areas specified in Boeing Service Bulletin 727-57-
0127, Revision 3, dated August 24, 1989; in accordance with Boeing 
Standard Overhaul Practices Manual D6-51702, Chapter 20-20-02, 
Revision 79, dated March 1, 1999.
    (d) Perform a high frequency eddy current inspection to detect 
cracking of certain wing ribs at the rib-to-stringer attachment in 
the areas specified in Boeing Service Bulletin 727-57-0127, Revision 
3, dated August 24, 1989; in accordance with Boeing Commercial Jet 
Nondestructive Test Manual, Chapter 51-00-00, Part 6, dated August 
5, 1997.

Repetitive Inspections and Corrective Action

    (e) If no crack is detected during any inspection required by 
either paragraph (c) or (d) of this AD, repeat the applicable 
inspection thereafter at intervals not to exceed 14,000 flight 
cycles.
    (f) If any crack is detected during any inspection required by 
either paragraph (c) or (d) of this AD, prior to further flight, 
repair in accordance with Boeing Service Bulletin 727-57-0127, 
Revision 3, dated August 24, 1989; or in accordance with a method 
approved by the Manager, Seattle Aircraft Certification Office 
(ACO), FAA Transport Airplane Directorate; or in accordance with 
data meeting the type certification basis of the airplane approved 
by a Boeing Company Designated Engineering Representative who has 
been authorized by the Manager, Seattle ACO, to make such findings. 
For a repair method to be approved by the Manager, Seattle ACO, as 
required by this paragraph, the Manager's approval letter must 
specifically reference this AD. Repeat the applicable inspection 
thereafter at intervals not to exceed 14,000 flight cycles, 
following accomplishment of the repair.

Terminating Action

    (g)(1) Accomplishment of the actions required by this AD 
constitutes terminating action for the inspections required by 
paragraph (a) of AD 94-07-08, as specified in Boeing Service 
Bulletin 727-57-0127, Revision 3, dated August 24, 1989.
    (2) Accomplishment of the structural modifications specified in 
either Boeing Service Bulletin 727-57-0127, Revision 2, dated 
February 13, 1976; or Revision 3, dated August 24, 1989; constitutes 
terminating action for the requirements of this AD.

Alternative Methods of Compliance

    (h) 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, FAA, Transport 
Airplane Directorate. An alternative method of compliance that 
provides an acceptable level of safety may be used if approved by 
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

    (i) 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

    (j) Except as provided by paragraph (f) of this AD, the repairs 
shall be done in accordance with Boeing Service Bulletin 727-57-
0127, Revision 3, dated August 24, 1989; 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.
    (k) This amendment becomes effective on May 16, 2000.

    Issued in Renton, Washington, on March 31, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-8516 Filed 4-10-00; 8:45 am]
BILLING CODE 4910-13-U