[Federal Register Volume 65, Number 91 (Wednesday, May 10, 2000)]
[Proposed Rules]
[Pages 30019-30021]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-11725]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-103-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-200, -300, -400, and -
500 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 737-200, -
300, -400, and -500 series airplanes. This proposal would require 
replacement of existing door handle mounting hub assemblies with new, 
improved hub assemblies. This proposal is prompted by reports of 
cracked or broken mounting hub assemblies for the interior door handles 
on the cabin doors. The actions specified by the proposed AD are 
intended to prevent cracking or breaking of the door handle mounting 
hub, which could result in the interior door handle breaking off while 
the door is being opened. In an emergency situation, this could impede 
evacuation of the airplane.

DATES: Comments must be received by June 26, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-103-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.
    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: Keith Ladderud, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2780; 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 2000-NM-103-AD.''

[[Page 30020]]

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-103-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports indicating that cracked or broken 
mounting hub assemblies for the interior door handles on the cabin 
doors have been found on certain Boeing Model 737-200, -300, -400, and 
-500 series airplanes. The primary use of the interior door handle is 
to be turned to latch the door after the door is shut using the assist 
handles. If the interior door handle is also used to close the door, 
the moment arm of the door handle puts too much force on the existing 
aluminum door handle mounting hub, which causes the mounting hub to 
crack or break. This condition, if not corrected, could result in the 
interior door handle breaking off while the door is being opened. In an 
emergency situation, this could impede evacuation of the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 737-25-
1322, Revision 2, dated February 19, 1998. That service bulletin 
describes procedures for replacement of existing door handle mounting 
hub assemblies in the forward and aft entry doors, forward galley door, 
and aft service door, with new, improved hub assemblies. The new 
mounting hub assemblies are made of stainless steel and are stronger 
than the existing aluminum mounting hub assemblies. 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 require accomplishment of the actions specified in 
the service bulletin described previously, except as discussed below.

Differences Between the Proposed Rule and the Service Information

    Operators should note that the proposed AD would require 
replacement of existing door handle mounting hub assemblies with new, 
improved hub assemblies within 18 months after the effective date of 
this AD. The service bulletin recommends that the mounting hub in the 
forward entry door be replaced at the next ``A'' check, and the 
mounting hub assemblies in the aft entry door, forward galley door, and 
aft service door be replaced at the next ``C'' check. In developing an 
appropriate compliance time for this proposed AD, the FAA considered 
not only the manufacturer's recommendation, but the degree of urgency 
associated with addressing the subject unsafe condition, the average 
utilization of the affected fleet, and the time necessary to replace 
the mounting hub assemblies (approximately 3 work hours per door). In 
light of all of these factors, the FAA finds an 18-month compliance 
time for initiating the proposed actions to be warranted, in that it 
represents an appropriate interval of time allowable for affected 
airplanes to continue to operate without compromising safety.

Cost Impact

    There are approximately 1,575 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 632 airplanes of U.S. 
registry would be affected by this proposed AD, that it would take 
approximately 12 work hours per airplane (3 work hours per door) to 
accomplish the proposed replacement, and that the average labor rate is 
$60 per work hour. Required parts would cost approximately $2,150 per 
airplane. Based on these figures, the cost impact of the proposed AD on 
U.S. operators is estimated to be $1,813,840, or $2,870 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 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 adding the following new 
airworthiness directive:

Boeing: Docket 2000-NM-103-AD.

    Applicability: Model 737-200, -300, -400, and -500 series 
airplanes; as listed in Boeing Service Bulletin 737-25-1322, 
Revision 2, dated February 19, 1998; 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 cracking or breaking of the door handle mounting hub, 
which could result in the interior door handle breaking off while 
the door is being opened, and, in an emergency situation, could 
impede evacuation of the airplane, accomplish the following:

[[Page 30021]]

Replacement

    (a) Within 18 months after the effective date of this AD, 
replace existing door handle mounting hub assemblies in the forward 
and aft entry doors, forward galley door, and aft service door, with 
new, improved hub assemblies, in accordance with Boeing Service 
Bulletin 737-25-1322, Revision 2, dated February 19, 1998.

    Note 2: Replacements accomplished prior to the effective date of 
this AD in accordance with Boeing Service Bulletin 737-25-1322, 
dated January 19, 1995, or Revision 1, dated December 19, 1996, are 
considered acceptable for compliance with paragraph (a) of this AD.

Alternative Methods 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 Aircraft Certification 
Office (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 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

    (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 May 4, 2000.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-11725 Filed 5-9-00; 8:45 am]
BILLING CODE 4910-13-U