[Federal Register Volume 65, Number 201 (Tuesday, October 17, 2000)]
[Proposed Rules]
[Pages 61289-61292]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-26595]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-295-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-200 and -300 Series 
Airplanes Equipped with a Main Deck Cargo Door Installed in Accordance 
with Supplemental Type Certificate (STC) SA2969SO

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 737-
200 and -300 series airplanes, that currently requires a one-time 
inspection to detect cracks of the lower frames and reinforcing angles 
of the main deck cargo door where the door latch fittings attach 
between certain fuselage stations and water lines, and replacement of 
any cracked part with a new part having the same part number. That AD 
was prompted by reports that, during the inspections required by the 
existing AD, cracks were found in the reinforcing angles of the main 
deck cargo door frame. This action would require, among other actions, 
an inspection to detect cracks of the lower frames and reinforcing 
angles of the main deck cargo door; replacement of any lower frame or 
reinforcing angle of the main deck cargo door when it has reached its 
maximum life limit. The actions specified by the proposed AD are 
intended to detect and correct cracking of the lower portion of the 
main deck cargo door frames, which could result in sudden 
depressurization, loss or opening of the main deck cargo door during 
flight, and loss of control of the airplane.

DATES: Comments must be received by November 16, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-295-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
9-anm-

[[Page 61290]]

<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="177967657a74787a7a7279635771767639707861">[email protected]</a>. Comments sent via fax or the Internet must contain 
``Docket No. 2000-NM-295-AD'' in the subject line and need not be 
submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Pemco World Air Services, 100 Pemco Drive, Dothan, AL 
36303. This information may be examined at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Rany Azzi, Aerospace Engineer, 
Airframe and Propulsion Branch, ACE-117A, FAA, Atlanta Aircraft 
Certification Office, One Crown Center, 1895 Phoenix Boulevard, Suite 
450, Atlanta, Georgia 30337-2748, telephone (770) 703-6083; fax (770) 
703-6097.

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.
    Submit comments using the following format:
    <bullet> Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    <bullet> For each issue, state what specific change to the proposed 
AD is being requested.
    <bullet> Include justification (e.g., reasons or data) for each 
request.
    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 2000-NM-295-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. 2000-NM-295-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On August 18, 2000, the FAA issued AD 2000-17-51, amendment 39-
11877 (65 FR 51752, August 25, 2000), applicable to certain Boeing 
Model 737-200 and -300 series airplanes, to require a one-time 
inspection to detect cracks of the lower frames and reinforcing angles 
of the main deck cargo door where the door latch fittings attach 
between certain fuselage stations (FS) and water lines (WL), and 
replacement of any cracked part with a new part having the same part 
number. That action was prompted by reports that, during the 
inspections required by the existing AD, cracks were found in the 
reinforcing angles of the main deck cargo door frame. The requirements 
of that AD are intended to detect and correct cracking of the lower 
portion of the main deck cargo door frames, which could result in 
sudden depressurization, loss or opening of the main deck cargo door 
during flight, and loss of control of the airplane.
    In the preamble of AD 2000-17-51, the FAA indicated that the 
actions required by that AD were considered ``interim action'' and that 
further rulemaking action was being considered to supersede that AD to 
require replacement of the main deck cargo door frames and reinforcing 
angles that have accumulated 7,000 or more total flight cycles with new 
parts. The FAA now has determined that further rulemaking action is 
indeed necessary, and this proposed AD follows from that determination.

Actions Since Issuance of Previous Rule

    Since the issuance of that AD, the FAA has reviewed and approved 
Pemco Service Bulletin 737-52-0037, Revision 2, dated September 13, 
2000, including Attachment 1, dated August 10, 2000. The service 
bulletin describes the following procedures:
    <bullet> A high frequency eddy current (HFEC) inspection to detect 
cracks of the lower frames and reinforcing angles of the main deck 
cargo door where the door latch fittings attach between FS 361.87 and 
FS 498.12 and WL 202.35 and WL 213.00;
    <bullet> Repetitive HFEC inspections of existing and replaced 
parts; and
    <bullet> Replacement of any lower frame or reinforcing angle of the 
main deck cargo door, if cracks are detected or when the frame or angle 
has reached its maximum life limit (i.e. 7,000 flight cycles), with a 
new part having the same part number.
    Accomplishment of the actions 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 2000-17-51 to require accomplishment of 
the actions specified in the service bulletin described previously.

Cost Impact

    There are approximately 35 Model 737-200 and -300 series airplanes 
of the affected design in the worldwide fleet. The FAA estimates that 2 
airplanes of U.S. registry would be affected by this proposed AD.
    It would take approximately 500 work hours per airplane to 
accomplish the proposed inspection, at an average labor rate of $60 per 
work hour. Based on these figures, the cost impact of the inspection 
proposed by this AD on U.S. operators is estimated to be $60,000, or 
$30,000 per airplane.
    It would take approximately 128 work hours per airplane to 
accomplish the proposed replacement, at an average labor rate of $60 
per work hour. Required parts would cost approximately $15,521 per 
airplane. Based on these figures, the cost impact of the proposed AD on 
U.S. operators is estimated to be $46,402, or $23,201 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. The cost 
impact figures discussed in AD rulemaking actions represent only the 
time necessary to perform the specific actions actually required by the 
AD. These figures typically do not include incidental costs, such as 
the time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.

[[Page 61291]]

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 39-11877 (65 FR 
51752, August 25, 2000), and by adding a new airworthiness directive 
(AD), to read as follows:

Boeing: Docket 2000-NM-295-AD. Supersedes AD 2000-17-51, Amendment 
39-11877.
    Applicability: Model 737-200 and -300 series airplanes, equipped 
with a main deck cargo door installed in accordance with 
Supplemental Type Certificate (STC) SA2969SO; 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 (c)(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 lower portion of the main 
deck cargo door frames, which could result in sudden 
depressurization, loss or opening of the main deck cargo door during 
flight, and loss of control of the airplane, accomplish the 
following:

Actions Addressing Door Frames or Reinforcing Angles That Have Been 
Replaced

    (a) For airplanes on which any door frame or reinforcing angle 
at the location where the door latch fittings attach between 
fuselage station (FS) 361.86 and FS 298.12 and water line (WL) 
202.35 and WL 213.00 has been replaced before the effective date of 
this AD: Do the actions specified in paragraphs (a)(1) and (a)(2) of 
this AD per the Accomplishment Instructions of Pemco Service 
Bulletin 737-52-0037, Revision 2, dated September 13, 2000, 
including Attachment 1, dated August 10, 2000.
    (1) Within 3,000 flight cycles after accomplishment of the 
replacement, do a high frequency eddy current (HFEC) inspection to 
detect cracks of the replaced lower frames or replaced reinforcing 
angles of the main deck cargo door, as applicable.
    (i) If no crack is detected, repeat the HFEC inspection 
thereafter at intervals of 1,300 flight cycles on the replaced part.
    (ii) If any crack is detected, before further flight, replace 
the cracked part with a new part having the same part number per the 
service bulletin. Within 3,000 flight cycles after accomplishment of 
the replacement, do the HFEC inspection required by paragraph (a)(1) 
of this AD.
    (2) Before or upon the accumulation of 7,000 total flight cycles 
on any lower frame or reinforcing angle of the main deck cargo door, 
replace the lower frame or reinforcing angle, as applicable, with 
new parts. Within 3,000 flight cycles after accomplishment of the 
replacement, do the HFEC inspection required by paragraph (a)(1) of 
this AD.

Actions Addressing Door Frames or Reinforcing Angles That Have Not Been 
Replaced

    (b) For airplanes on which any door frame or reinforcing angle 
at the location where the door latch fittings attach between FS 
361.86 and FS 298.12 and WL 202.35 and WL 213.00 has NOT been 
replaced before the effective date of this AD: Within 1,300 flight 
cycles after accomplishment of the HFEC inspection required by AD 
2000-17-51, amendment 39-11877, do the action specified in either 
paragraph (b)(1) or (b)(2) of this AD, as applicable, per the 
Accomplishment Instructions of Pemco Service Bulletin 737-52-0037, 
Revision 2, dated September 13, 2000, including Attachment 1, dated 
August 10, 2000.
    (1) For airplanes that have accumulated less than 7,000 total 
flight cycles since installation of STC SA2969SO: Do an HFEC 
inspection to detect cracks of the lower frames and reinforcing 
angles of the main deck cargo door where the door latch fittings 
attach between FS 361.87 and FS 498.12 and WL 202.35 and WL 213.00.
    (i) If no crack is detected, do the actions specified in 
paragraphs (b)(1)(i)(A) and (b)(1)(i)(B) of this AD.
    (A) Repeat the HFEC inspection thereafter at intervals of 1,300 
flight cycles on the airplane, but not to exceed the accumulation of 
7,000 total flight cycles on the airplane.
    (B) Before the accumulation of 7,000 total flight cycles on the 
airplane, replace the lower frame and reinforcing angle with new 
parts per the service bulletin. Within 3,000 flight cycles after 
accomplishment of the replacement, do the HFEC inspection required 
by paragraph (a)(1) of this AD.
    (ii) If any crack is detected, before further flight, replace 
the cracked part with a new part having the same part number per the 
service bulletin. Within 3,000 flight cycles after accomplishment of 
the replacement, do the HFEC inspection required by paragraph (a)(1) 
of this AD.
    (2) For airplanes that have accumulated 7,000 or more total 
flight cycles since installation of STC SA2969SO: Replace the lower 
frames and reinforcing angles with new parts. Within 3,000 flight 
cycles after accomplishment of the replacement, do the HFEC 
inspection required by paragraph (a)(1) of this AD.

Alternative Methods of Compliance

    (c)(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, Atlanta

[[Page 61292]]

Aircraft Certification Office (ACO), FAA. Operators shall submit 
their requests through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Atlanta ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Atlanta ACO.

    (2) Alternative methods of compliance, approved previously in 
accordance with AD 2000-17-51, amendment 39-11877, are approved as 
alternative methods of compliance with the initial HFEC inspection 
required by paragraph (a)(1) of this AD.

Special Flight Permits

    (d) 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 October 11, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-26595 Filed 10-16-00; 8:45 am]
BILLING CODE 4910-13-P


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