[Federal Register Volume 64, Number 224 (Monday, November 22, 1999)]
[Proposed Rules]
[Pages 63753-63755]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-30372]


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 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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  Federal Register / Vol. 64, No. 224 / Monday, November 22, 1999 / 
Proposed Rules  

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-293-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 727 and 727C Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 727 and 727C 
series airplanes. This proposal would require one-time inspections of 
the exterior body skin located at the forward corners of the mid-galley 
door hinge cutouts to detect cracking, and corrective actions, if 
necessary. This proposal also would require modification of the body 
skin of the mid-galley door hinge cutouts. This proposal is prompted by 
a report indicating that, during fatigue testing on a Boeing Model 727 
series airplane, a crack was found in the body skin at the lower 
forward corners of the mid-galley door hinge cutouts due to cabin 
pressurization cycles. The actions specified by the proposed AD are 
intended to prevent such fatigue cracking of the body skin, which could 
result in reduced structural integrity of the fuselage and consequent 
loss of cabin pressurization.

DATES: Comments must be received by January 6, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-293-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 Linda 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 98-NM-293-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. 98-NM-293-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports indicating that, during fatigue 
testing on a Boeing Model 727 series airplane, a crack was found in the 
body skin at the lower forward corners of the mid-galley door hinge 
cutouts. The crack was attributed to fatigue induced by cabin 
pressurization cycles. Such cracking, if not corrected, could result in 
reduced structural integrity of the fuselage and consequent loss of 
cabin pressurization.

Other Related Rulemaking

    On January 16, 1990, the FAA issued AD 90-06-09, amendment 39-6488 
(55 FR 8370, March 7, 1990), applicable to certain Boeing Model 727 
series airplanes, which currently requires the incorporation of certain 
structural modifications specified by Boeing Document No. D6-54860, 
Revision C, dated December 11, 1989, ``Aging Airplane Service Bulletin 
Structural Modification Program--Model 727.'' That Boeing document 
references numerous Boeing service bulletins that specify various 
modification actions that are mandated by AD 90-06-09. That AD was 
prompted by reports of incidents involving fatigue cracking and 
corrosion in transport category airplanes that were approaching or had 
exceeded their design life goal. The actions required by that AD are 
intended to prevent a degradation in the structural capabilities of the 
affected airplanes, which could result in structural failure. That 
action also reflects the FAA's decision that long-term continued 
operational safety should be assured by actual modification of the 
airframe rather than repetitive inspection.
    Since issuance of that AD, the FAA has determined that the same 
unsafe condition addressed in that AD may exist on certain additional 
Model 727 and 727C series airplanes. The FAA was advised that three 
Model 727 and 727C series airplanes (line numbers 153, 290, and 339) 
were omitted inadvertently from the applicability of AD 90-06-09 
because those airplanes had been excluded inadvertently from the 
effectivity of Section I.A. of Boeing Service Bulletin 727-53-0054, 
Revision 1, dated November 16, 1989. Therefore, these additional 
airplanes are also subject to the same unsafe condition addressed in AD 
90-06-09.

[[Page 63754]]

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 727-53-
0054,
    Revision 1, which describes a modification to the corners of the 
hinge cutouts and provides a top kit and instructions for installing 
doublers. Procedures include a close (detailed) visual inspection and a 
high-frequency eddy current (HFEC) inspection of the forward upper and 
lower corners of the mid-galley door hinge cutouts for cracks in the 
body skin. If no cracks are found, procedures specify either a 
modification, which includes modifying cutout corners and installing 
doublers, or a reinspection at ``C'' check intervals until 
accomplishment of the modification. If cracks are within specified 
repair limits, procedures include stop-drilling cracks, modifying 
cutout corners, and installing doublers. If cracks exceed specified 
repair limits, procedures specify contacting the manufacturer for 
repair instructions. Accomplishment of the modification is intended to 
increase the fatigue life of the body skin adjacent to the forward 
corners of the mid-galley door hinge cutouts.
    The procedures specified by Revision 1 of the service bulletin are 
essentially the same as those procedures included in Boeing Document 
D6-54860, Revision C, as cited in AD 90-06-09, and the procedures 
specified in the original issue of Boeing Service Bulletin 727-53-0054.
    Accomplishment of the actions specified in AD 90-06-09 is 
acceptable for compliance with the requirements of this proposed AD.

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 require accomplishment of the actions specified in 
Revision 1 of the service bulletin described previously, except as 
described below in the Differences section of this AD.
    Since this AD expands the applicability of AD 90-06-09, the FAA has 
considered a number of factors in determining whether to issue a new AD 
or to supersede the ``old'' AD. Although the three additional airplanes 
included in the applicability of this proposed AD were inadvertently 
omitted from Boeing Service 727-53-0054, numerous other service 
bulletins referenced in Boeing Document No. D6-54860, Revision C, 
(cited in AD 90-06-09) included those additional airplanes in the 
effectivity. The FAA also has considered the entire fleet size that 
would be affected by superseding AD 90-06-09 and the consequent 
workload associated with revising maintenance record entries. In light 
of this, the FAA has determined that a less burdensome approach is to 
issue a separate AD applicable only to these additional airplanes. This 
proposed AD would not supersede AD 90-06-09; airplanes listed in the 
applicability of AD 90-06-09 are required to continue to comply with 
the requirements of that AD. This proposed AD is a separate AD action, 
and is applicable only to Boeing Model 727 and 727C series airplanes, 
line numbers 153, 290, and 339; certificated in any category.

Differences Between Proposed AD and Relevant Service Information

    Operators should note that the proposed AD differs from Boeing 
Service Bulletin 727-53-0054, Revision 1, as follows:
     The effectivity of Revision 1 includes Model 727-100 
series airplanes, line positions 1 through 474 inclusive. However, the 
applicability of this proposal includes Model 727 and 727C series 
airplanes, line numbers 153, 290, and 339 inclusive, which were 
inadvertently omitted from AD-90-06-09.
     Although Revision 1 specifies that, in certain cases, 
repetitive inspections may be performed in lieu of a modification, this 
proposal does not allow such action. Instead, this proposal would 
require accomplishment of a repair and modification if cracking is 
detected, or a modification if no cracking is detected. The FAA has 
determined that long-term continued operational safety will be better 
assured by design changes to remove the source of the problem, rather 
than by repetitive inspections. Long-term inspections may not be 
providing the degree of safety assurance necessary for the transport 
airplane fleet. This, coupled with a better understanding of the human 
factors associated with numerous continual inspections, has led the FAA 
to consider placing less emphasis on inspections and more emphasis on 
design improvements. The proposed repair and modification requirement 
is in consonance with these conditions.
     Paragraph III.C. of the Accomplishment Instructions of 
Revision 1 specifies that if any crack is found that is greater than 
1.00 inch, the manufacturer must be contacted for repair instructions. 
However, this proposal requires the repair of those conditions to 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.
     Figure 1 of Revision 1 specifies a ``close visual 
inspection'' of the body skin at the forward corners of mid-galley door 
hinge cutouts. However, this AD would require a ``detailed visual 
inspection'' of the body skin at those locations.

Cost Impact

    There are approximately 1,516 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 3 airplanes of U.S. 
registry would be affected by this proposed AD.
    The FAA estimates that it would take approximately 1 work hour per 
airplane to accomplish the required inspections of the body skin at the 
corners of the mid-galley door hinge cutouts, and that the average 
labor rate is $60 per work hour. Based on these figures, the cost 
impact of the required inspections on U.S. operators is estimated to be 
$180, or $60 per airplane.
    The FAA also estimates that it would take approximately 28 work 
hours per airplane to accomplish the repair and modification, and that 
the average labor rate is $60 per work hour. Required parts would cost 
approximately $1,023 per airplane. Based on these figures, the cost 
impact of the proposed AD on U.S. operators is estimated to be $8,109, 
or $2,703 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the 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

[[Page 63755]]

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 adding the following new 
airworthiness directive:

Boeing: Docket 98-NM-293-AD.

    Applicability: Model 727 and 727C series airplanes, line numbers 
153, 290, and 339 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 (b) 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 fatigue cracking of the body skin at the forward 
corners of the mid-galley door hinge cutouts, which could result in 
reduced structural integrity of the fuselage and consequent loss of 
cabin pressurization, accomplish the following:

One-Time Inspections

    (a) 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, perform a one-time detailed visual 
inspection and a high frequency eddy current inspection of the 
exterior body skin located adjacent to the forward corners of the 
mid-galley door hinge cutouts for cracking in accordance with Boeing 
Service Bulletin 727-53-0054, Revision 1, dated November 16, 1989.

    Note 2: For the purposes of this AD, a detailed visual 
inspection is defined as: ``An intensive examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at an intensity 
deemed appropriate by the inspector. Inspection aids such as 
mirrors, magnifying lenses, etc. may be used. Surface cleaning and 
elaborate access procedures may be required.''

Repairs and Modification

    (1) If no cracking is found during any inspection, prior to 
further flight, modify the body skin at the forward corners of the 
mid-galley door hinge cutouts, in accordance with Boeing Service 
Bulletin 727-53-0054, Revision 1, dated November 16, 1989. No 
further action is required by this AD.
    (2) If any cracking is found during any inspection, prior to 
further flight, accomplish the requirements of either paragraph 
(a)(2)(i) or (a)(2)(ii) of this AD, as applicable.
    (i) If any crack is less than or equal to 1.00 inch, accomplish 
the repair and modification in accordance with Boeing Service 
Bulletin 727-53-0054, Revision 1, dated November 16, 1989. No 
further action is required by this AD.
    (ii) If any crack is greater than 1.00 inch, accomplish the 
repair and modification 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. No further action is required by this AD.

    Note 3: Accomplishment of the actions required by AD 90-06-09, 
amendment 39-6488, is considered acceptable for compliance with this 
AD.

Alternative Method of Compliance

    (b) 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. 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 4: 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

    (c) 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.

    Issued in Renton, Washington, on November 16, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-30372 Filed 11-19-99; 8:45 am]
BILLING CODE 4910-13-U