[Federal Register Volume 64, Number 193 (Wednesday, October 6, 1999)]
[Proposed Rules]
[Pages 54246-54248]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-26089]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-75-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 727 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain Boeing Model 727 
series airplanes, that currently requires repetitive inspections to 
detect cracking of the rear spar web or fuel leakage of the wing center 
section, and repair, if necessary. That action also provides for an 
optional modification of the rear spar web that constitutes terminating 
action for the repetitive inspections. That action was prompted by 
several reports of fuel leakage due to cracking of the rear spar web of 
the wing center section. This action would require accomplishment of 
the previously optional terminating action. The actions specified by 
the proposed AD are intended to prevent cracking of the rear spar web, 
which could permit fuel leakage into the airflow multiplier, and could 
result in an electrical short that could cause a fire.

DATES: Comments must be received by November 22, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-75-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule 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.

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:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NM-75-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 99-NM-75-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On December 3, 1997, the FAA issued AD 97-25-15, amendment 39-10239 
(62 FR 65355, December 12, 1997), applicable to certain Boeing Model 
727 series airplanes, to require repetitive inspections to detect 
cracking of the rear spar web or fuel leakage of the wing center 
section, and repair, if necessary. That action also provides for an 
optional modification of the rear spar web that constitutes terminating 
action for the repetitive inspections. That action was prompted by 
several reports of fuel leakage due to cracking of the rear spar web of 
the wing center section. The requirements of that AD are intended to 
detect and correct such cracking of the rear spar web, which could 
permit fuel leakage into the airflow multiplier, and could result in an 
electrical short that could cause a fire.

Actions Since Issuance of Previous Rule

    When AD 97-25-15 was issued, it contained a provision for the 
optional modification of the rear spar web, which, if accomplished, 
would constitute terminating action for the repetitive inspections 
required by that AD. In the preamble to AD 97-25-15, the FAA indicated 
that the actions required by that AD were considered ``interim action'' 
and that further rulemaking action was being considered to require the 
modification of the rear spar web of the wing center section. The FAA 
now has determined that further rulemaking action is indeed necessary, 
and this proposed AD follows from that determination.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 727-
57A0182, Revision 1, dated February 25, 1999. The procedures described 
in Revision 1 are essentially similar to those described in the 
original issue of the service bulletin, which was referenced as the 
appropriate source of service information for the actions in AD 97-25-
15. Accomplishment of the modification specified in the service 
bulletin is intended to adequately address the identified unsafe 
condition.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would supersede AD 97-25-15, to continue to require 
repetitive inspections to detect cracking of the rear spar web or fuel 
leakage of the wing center section, and repair, if necessary. This 
proposed AD would also require modification of the rear spar web, which 
would constitute terminating action for the repetitive inspections. 
These actions would be required to be accomplished in accordance with 
the service bulletin described previously.

Cost Impact

    There are approximately 970 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 659 airplanes of U.S. registry 
would be affected by this proposed AD: 641 ``Group 1'' airplanes and 18 
``Group 2'' airplanes, as listed in the service bulletin.
    The inspection that is currently required by AD 97-25-15 takes 
approximately 2 work hours per

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airplane to accomplish, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the currently required 
actions on U.S. operators is estimated to be $79,080, or $120 per 
airplane, per inspection cycle.
    The new modification that is proposed in this AD action would take 
approximately 60 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts would cost 
approximately $6,434 per airplane for ``Group 1'' airplanes, and $6,689 
per airplane for ``Group 2'' airplanes. Based on these figures, the 
cost impact of the proposed requirements of this AD on U.S. operators 
is estimated to be $6,616,996, or $10,034 per ``Group 1'' airplane and 
$10,289 per ``Group 2'' airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the current or proposed 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.

Regulatory Impact

    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) Is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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 removing amendment AD 97-25-15, 
amendment 39-10239 (62 FR 65355, December 27, 1997), and by adding a 
new airworthiness directive (AD), to read as follows:

Boeing:  Docket 99-NM-75-AD. Supersedes AD 97-25-15, Amendment 39-
10239.

    Applicability: Model 727 series airplanes having line numbers 
858 through 864 inclusive, 867 through 869 inclusive, 872 through 
883 inclusive, and 885 through 1832 inclusive; 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)(1) 
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 cracking of the rear spar web, which could permit 
fuel leakage into the airflow multiplier, and could result in an 
electrical short that could cause a fire, accomplish the following:

Restatement of the Requirements of AD 97-25-15

Inspections

    (a) Prior to the accumulation of 15,000 total flight cycles, or 
within 300 flight cycles after December 27, 1997 (the effective date 
of AD 97-25-15, amendment 39-10239), whichever occurs later: 
Accomplish the inspections specified in either paragraph (a)(1) or 
(a)(2) of this AD, in accordance with Boeing Alert Service Bulletin 
727-57A0182, dated September 18, 1997, or Boeing Service Bulletin 
727-57A0182, Revision 1, dated February 25, 1999. For purposes of 
the AD, the access panels specified in the alert service bulletin 
need not be removed; the access panels need only be opened.

    Note 2: The fuel tank of the wing center section may be filled 
with fuel to assist in detecting cracking or fuel leakage during the 
accomplishment of the visual inspections required by this AD.

    (1) Perform a visual inspection using a borescope or mirror to 
detect cracking of the rear spar web and/or fuel leakage of the wing 
center section between right body buttock line (BBL) 40 and left BBL 
40, in accordance with Part I of the Accomplishment Instructions of 
the service bulletin. Thereafter, repeat this inspection at 
intervals not to exceed 300 flight cycles. Or
    (2) Perform an ultrasonic and high frequency eddy current (HFEC) 
inspection to detect cracking of the rear spar web of the wing 
center section between right BBL 40 and left BBL 40, in accordance 
with Part II of the Accomplishment Instructions of the service 
bulletin. Thereafter, repeat this inspection at intervals not to 
exceed 3,000 flight cycles.

Repair

    (b) If any cracking of the rear spar web and/or fuel leakage of 
the wing center section is detected between right BBL 40 and left 
BBL 40 near the upper machined land radius, prior to further flight, 
repair in accordance with Part III of the Accomplishment 
Instructions in Boeing Alert Service Bulletin 727-57A0182, dated 
September 18, 1997, or Boeing Service Bulletin 727-57A0182, Revision 
1, dated February 25, 1999. Accomplishment of this repair 
constitutes terminating action for the repetitive inspection 
requirements of this AD.
    (c) If any cracking of the rear spar web and/or fuel leakage of 
the wing center section is detected that is outside the area 
specified in paragraph (b) of this AD, prior to further flight, 
repair in accordance with a method approved by the Manager, Seattle 
Aircraft Certification Office (ACO), FAA, Transport Airplane 
Directorate. 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.

New Requirements of this AD

Modification

    (d) Prior to the accumulation of 60,000 total flight cycles, or 
within 3,000 flight cycles after the effective date of this AD, 
whichever occurs later, accomplish an ultrasonic and HFEC inspection 
in accordance with the requirements of paragraph (a)(2) of this AD.
    (1) If no cracking is detected, prior to further flight, modify 
the rear spar web of the center section of the fuel tank between 
right BBL 40 and left BBL 40, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 727-57A0182, dated 
September 18, 1997, or Boeing Service Bulletin 727-57A0182, Revision 
1, dated February 25, 1999. Accomplishment of this modification 
constitutes terminating action for the repetitive inspection 
requirements of this AD.
    (2) If any cracking is detected, prior to further flight, repair 
and modify in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 727-57A0182, dated September 18, 1997, 
or Boeing Service Bulletin 727-57A0182, Revision 1, dated February 
25, 1999. Accomplishment of this modification constitutes 
terminating action for the

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repetitive inspection requirements of this AD.

Alternative Methods of Compliance

    (e)(1) 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.
    (e)(2) Alternative methods of compliance, approved previously in 
accordance with AD 97-25-15, amendment 39-10239, are approved as 
alternative methods of compliance with this AD.

    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

    (f) 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, provided the 
limitations specified in paragraphs (f)(1) through (f)(6) of this AD 
are included in the special flight permit:
    ``(1) Required trip and reserve fuel must be carried in the No. 
1 and No. 3 outer wing tanks.
    (2) Wing center tank No. 2 must be empty of fuel.
    (3) The fuel system must be checked for normal operation prior 
to flight by verifying that all boost pumps are operational; 
configuring the fuel system by turning on all boost pumps in the 
No.'s 1 and 3 outer wing tanks and by opening all crossfeed valve 
selectors; and by confirming that fuel is not bypassing tank No. 2 
check valves by observing that there is not leakage into tank No. 2.
    (4) Maintain a minimum of 5,300 pounds of fuel in tanks No. 1 
and No. 3 to prevent uncovering the fuel bypass valve.
    (5) The fuel quantity indication system must be operational in 
all three tanks.
    (6) The effects of loading fuel only in the wing tanks on the 
airplane weight and balance must be considered and accounted for.''

    Issued in Renton, Washington, on September 30, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-26089 Filed 10-5-99; 8:45 am]
BILLING CODE 4910-13-U