[Federal Register Volume 65, Number 76 (Wednesday, April 19, 2000)]
[Proposed Rules]
[Pages 20924-20927]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-9821]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-363-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 707, 727C, and 727-100C 
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 707, 
727C, and 727-100C series airplanes, that currently requires repetitive 
inspections to detect cracking of the main cargo door skin and frames, 
and repair, if necessary. The existing AD also provides optional 
terminating modifications. This action would mandate follow-on 
repetitive inspections of repaired or modified areas for certain 
airplanes. This proposal is prompted by reports of cracking and/or 
tearing of the main cargo door outer skin and subsequent failure of the 
door frame. The actions specified by the proposed AD are intended to 
detect and correct such cracking and/or tearing, which could result in 
failure of the door frame and consequent rapid decompression of the 
airplane.

DATES: Comments must be received by June 5, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-363-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.

[[Page 20925]]

Comments may be inspected at this location between 9 a.m. and 3 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: Walt 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-363-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-363-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On January 17, 1983, the FAA issued AD 83-02-09, amendment 39-4549 
(48 FR 6953, February 17, 1983), applicable to certain Boeing Model 
707, 727C, and 727-100C airplanes, to require inspection and repair, if 
necessary, of the main cargo door structure. That action was prompted 
by reports of skin cracking and door frame failures. The requirements 
of that AD are intended to detect cracking prior to reaching critical 
length, which could result in rapid decompression or loss of a portion 
of the main cargo door.

Actions Since Issuance of Previous Rule

    Since the issuance of that AD, the FAA has reviewed and approved 
Boeing Service Bulletin 727-52A0079, Revision 6, dated January 11, 
1990. The service bulletin describes procedures for repetitive detailed 
visual, eddy current, and X-ray inspections of the main cargo door 
outer skin and the door frames between body stations (BS) 505 and 595 
to detect cracking, and repair of any cracks. The service bulletin also 
describes procedures for modification of the main cargo door and 
detailed visual and eddy current inspections of the modified or 
repaired areas. Revisions 4 and 5 of the service bulletin were 
referenced in the existing AD as an appropriate source of service 
information for accomplishment of the inspections and modifications for 
the Model 727 series airplanes.
    The FAA also has reviewed and approved Revision 4 of Boeing Service 
Bulletin 2999, dated January 31, 1991. Revision 3 of the service 
bulletin was referenced in the existing AD as the appropriate source of 
service information for accomplishment of the inspections and 
modifications for the Model 707 series airplanes. The requirements for 
inspections and modifications of the Model 707 are unchanged in this 
proposed AD because the detailed visual and eddy current inspections of 
the modified or repaired areas are required by AD 85-12-01 R1, 
amendment 39-5439 (51 FR 36002, October 8, 1986).

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 83-02-09 to continue to require 
repetitive inspections to detect cracking of the main cargo door outer 
skin and frames, and repair, if necessary. This proposed AD would 
mandate follow-on repetitive inspections of modified or repaired areas 
for certain airplanes.
    Paragraph (e) of the existing AD will not be restated in this 
proposal due to the FAA's determination that calculating the number of 
landings/flight cycles by fleet average would not allow for detection 
of cracks in a timely manner.
    Additionally, restatement of the requirements of the existing AD 
has been revised to remove all references to the use of ``later FAA-
approved revisions of the applicable service bulletin,'' in order to be 
consistent with FAA policy in that regard. The FAA has determined that 
this change will not increase the economic burden on any operator, nor 
will it increase the scope of the AD, since later revisions of the 
service bulletin may be approved as an alternative method of compliance 
with this AD, as provided by paragraph (g)(1) of this AD.

Difference Between Proposed Rule and Service Bulletins

    Operators should note that, although the service bulletins specify 
that the manufacturer may be contacted for disposition of certain 
repair conditions, this proposed AD would require 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.

Cost Impact

    There are approximately 50 Model 707 and 308 Model 727 series 
airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 1 Model 707 and 81 Model 727 airplanes of U.S. registry 
would be affected by this proposed AD.
    The cost impact information in AD 83-02-09 inadvertently contained 
information relevant only to the X-ray inspection; however, since the 
detailed visual and eddy current inspections are also acceptable 
methods to detect cracking, this proposed AD includes the estimated 
number of work hours necessary to accomplish any one of the three 
inspection methods. Additionally, the FAA has recently reviewed the 
figures it has used over the past several years in calculating the 
economic impact of AD activity. In order to account for various 
inflationary costs in the airline industry, the FAA has determined that 
it is necessary to increase the labor rate used in these calculations 
from $40 per work hour to

[[Page 20926]]

$60 per work hour. The cost impact information, below, has been revised 
to reflect these changes.
    Should an operator elect to accomplish the detailed visual 
inspection that is currently required by AD 83-02-09, it would take 
approximately 1 work hour per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the detailed visual inspection is estimated to be $60 per 
airplane.
    Should an operator elect to accomplish the eddy current inspection 
that is currently required by AD 83-02-09, it would take approximately 
1 work hour per airplane to accomplish, at an average labor rate of $60 
per work hour. Based on these figures, the cost impact of the eddy 
current inspection is estimated to be $60 per airplane.
    Should an operator elect to accomplish the X-ray inspection that is 
currently required by AD 83-02-09, it would take approximately 3 work 
hours per airplane to accomplish, at an average labor rate of $60 per 
work hour. Based on these figures, the cost impact of the X-ray 
inspection is estimated to be $180 per airplane.
    The detailed visual inspection (for Model 727 series airplanes 
only) proposed by this AD would take approximately 1 work hour per 
airplane to accomplish, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the detailed visual 
inspection is estimated to be $4,860, or $60 per airplane.
    The eddy current inspection (for Model 727 series airplanes only) 
proposed by this AD would take approximately 1 work hour per airplane 
to accomplish, at an average labor rate of $60 per work hour. Based on 
these figures, the cost impact of the eddy current inspection is 
estimated to be $4,860, or $60 per 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 a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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 39-4549 (48 FR 
6953, February 17, 1983), and by adding a new airworthiness directive 
(AD), to read as follows:

Boeing: Docket 99-NM-363-AD. Supersedes AD 83-02-09, Amendment 39-
4549.

    Applicability: Model 707, 727C, and 727-100C series airplanes; 
as listed in Boeing Service Bulletins 2999, Revision 3, dated 
January 12, 1972, and 727-52-79, Revision 4, dated June 19, 1981; 
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 (g)(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 detect and correct cracking of the main cargo door skin and 
frames, which could result in failure of the door frame, and 
consequent rapid decompression of the airplane, accomplish the 
following:

    Note 2: For the purposes of this AD, a detailed visual 
inspection is defined as: ``An intensive visual 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 
intensity deemed appropriate by the inspector. Inspection aids such 
as mirror, magnifying lenses, etc., may be used. Surface cleaning 
and elaborate access procedures may be required.''

Restatement of Requirements of AD 83-02-09

Initial Inspection

    (a) Within 500 landings after March 3, 1983 (the effective date 
of AD 83-02-09, amendment 39-4549), or prior to the accumulation of 
25,000 total landings after March 3, 1983, whichever occurs later: 
Perform an inspection (detailed visual, eddy current, or X-ray) to 
detect cracks of the main cargo door outer skin and frames between 
body stations (BS) 505 and 595, from the lower edge of the door 
hinge a minimum of 6 inches down, and 6 inches above, and 3 inches 
below the center line of stringer 10, in accordance with Boeing 
Service Bulletin 2999, Revision 3, dated January 12, 1972, or 
Revision 4, dated January 31, 1991 (for Model 707 series airplanes); 
or Boeing Service Bulletin 727-52-79, Revision 4, dated June 19, 
1981, or Boeing Alert Service Bulletin 727-52A0079, Revision 5, 
dated June 17, 1983, or Revision 6, dated January 11, 1990 (for 
Model 727 series airplanes); as applicable.

Repetitive Inspections

    (b) Repeat the inspection required by paragraph (a) of this AD 
at the times specified in paragraph (b)(1), (b)(2) or (b)(3) of this 
AD; as applicable; until accomplishment of the modification required 
by paragraph (d) of this AD.
    (1) Repeat the detailed visual inspection at intervals not to 
exceed 500 landings.
    (2) Repeat the eddy current inspection at intervals not to 
exceed 750 landings.
    (3) Repeat the X-ray inspection at intervals not to exceed 1,000 
landings.

Repair

    (c) If any cracking is detected during any inspection required 
by paragraph (a) or (b) of this AD: Prior to further flight, repair 
any cracks detected in accordance with Boeing Service Bulletin 2999, 
Revision 3, dated January 12, 1972, or Revision 4, dated January 31, 
1991 (for Model 707 series airplanes); or Boeing Service Bulletin 
727-52-79, Revision 4, dated June 19, 1981, or Boeing Alert Service 
Bulletin 727-52A0079, Revision 5, dated June 17, 1983, or Revision 
6, dated January 11, 1990 (for Model 727 series airplanes), as 
applicable.

Optional Terminating Action

    (d) Modification of the main cargo door in accordance with Part 
II, Option 1 or Option

[[Page 20927]]

2, as applicable, of the Accomplishment Instructions of Boeing 
Service Bulletin 2999, Revision 3, dated January 12, 1972, or 
Revision 4, dated January 31, 1991 (for Model 707 series airplanes); 
or Boeing Service Bulletin 727-52-79, Revision 4, dated June 19, 
1981, or Boeing Alert Service Bulletin 727-52A0079, Revision 5, 
dated June 17, 1983, or Revision 6, dated January 11, 1990 (for 
Model 727 series airplanes); as applicable; constitutes terminating 
action for the requirements of paragraphs (a) and (b) of this AD.

New Requirements of This AD

Post-Repair/Post-Mod Repetitive Inspections

    (e) For Model 727 series airplanes: Within 27,000 flight cycles 
after accomplishment of the repair specified in paragraph (c) of 
this AD, and/or the modification specified in paragraph (d) of this 
AD, as applicable; or within 1,000 flight cycles after the effective 
date of this AD; whichever occurs later; accomplish the requirements 
of paragraph (e)(1) or (e)(2) of this AD, as applicable.
    (1) For airplanes that have accomplished the modification 
specified in Part II, Option 1, of the Accomplishment Instructions 
of Boeing Service Bulletin 727-52-79, Revision 4, dated June 19, 
1981, or Boeing Alert Service Bulletin 727-52A0079, Revision 5, 
dated June 17, 1983, or Revision 6, dated January 11, 1990: Perform 
a detailed visual and eddy current inspection of the modified area 
and/or any repaired area, to detect cracks, in accordance with the 
service bulletin. Repeat the inspections at intervals not to exceed 
3,800 flight cycles.
    (2) For airplanes that have accomplished the modification 
specified in Part II, Option 2, of the Accomplishment Instructions 
of Boeing Service Bulletin 727-52-79, Revision 4, dated June 19, 
1981, or Boeing Alert Service Bulletin 727-52A0079, Revision 5, 
dated June 17, 1983, or Revision 6, dated January 11, 1990: Perform 
an internal and external detailed visual and an eddy current 
inspection of the modified area to detect cracks in accordance with 
the service bulletin. Repeat the inspections at intervals not to 
exceed 3,800 flight cycles.

Repair

    (f) If any cracking is detected during any inspection required 
by paragraph (e)(1) or (e)(2) of this AD: Prior to further flight, 
repair any cracks detected 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.

Alternative Methods of Compliance

    (g)(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.
    (2) Alternative methods of compliance approved previously in 
accordance with AD 83-02-09, amendment 39-4549, 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.


    Note 4: Incorporation of the Boeing Model 707-720 Supplemental 
Structural Inspection Document (SSID) into the operator's approved 
airplane maintenance program constitutes an approved alternative 
method of compliance for Model 707 and 720 series airplanes.

Special Flight Permits

    (h) 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 April 13, 2000.
Charles D. Huber,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-9821 Filed 4-18-00; 8:45 am]
BILLING CODE 4910-13-U