[Federal Register: September 18, 2003 (Volume 68, Number 181)]
[Proposed Rules]
[Page 54684-54686]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18se03-18]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2001-NM-156-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
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 737-100, -
200, -200C, -300, -400, and -500 series airplanes. This proposal would
require replacing the existing screw, nut, and washers that attach the
latch cable assembly to the latch block assembly of the door mounted
escape slides, with the new, improved screw, nut, and washers. This
action is necessary to prevent the latch cable assembly from
disconnecting from the latch block assembly of the door mounted escape
slide, which could result in an escape slide not deploying in an
emergency situation. This action is intended to address the identified
unsafe condition.
DATES: Comments must be received by November 3, 2003.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2001-NM-156-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
[[Page 54685]]
may also be sent via the Internet using the following address: 9-anm-
nprmcomment@faa.gov. Comments sent via fax or the Internet must contain
``Docket No. 2001-NM-156-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 or 2000 or
ASCII text.
The service information referenced in the proposed rule may be
obtained from Boeing Commercial Airplane Group, PO 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,
Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 917-6435; fax (425) 917-6590.
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 action may be changed in
light of the comments received.
Submit comments using the following format:
[sbull] 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.
[sbull] For each issue, state what specific change to the proposed
AD is being requested.
[sbull] 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 action must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 2001-NM-156-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. 2001-NM-156-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
An operator reported that the cable on a door mounted escape slide
had disconnected from the latch block assembly on a Boeing Model 737
series airplane. Investigation revealed that a production change had
increased the size of the latch cable loops, which could allow the
latch cable assembly to disconnect from the latch block assembly. This
condition, if not corrected, could result in an escape slide not
deploying in an emergency situation, and consequent reduction in the
number of exits available in an evacuation.
Related Rulemaking
On November 29, 1985, the FAA issued AD 85-25-04, amendment 39-5179
(50 FR 49923, December 6, 1985). That AD required inspecting the escape
slides and modifying the escape slide containers; and, on certain
airplanes, the AD required inspecting, modifying escape slide
installations, and functional testing; in accordance with Boeing
Service Bulletin 737-25A1182, Revision 2, Parts I, III and IV, dated
November 12, 1985.
On February 25, 1986, the FAA issued AD 86-05-04, amendment 39-5249
(51 FR 7433, March 4, 1986). That AD required installing retaining
straps for the escape slide covers on the aft doors, in accordance with
Boeing Service Bulletin 737-25A1182, Revision 2, Part II, dated
November 12, 1985.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Special Attention Service
Bulletin 737-25-1434, dated March 22, 2001, which describes procedures
for replacing the existing screw, nut, and washers that attach the
latch cable assembly to the latch block assembly of the door mounted
escape slides, with the new, improved screw, nut, and washers.
Accomplishment of the actions specified in the service bulletin is
intended to adequately address the identified unsafe condition.
The service bulletin also specifies installation of the double loop
escape slide latch cable assembly as described in Boeing Service
Bulletin 737-25A1182, dated September 18, 1985, as a concurrent
requirement. (See ``Related Rulemaking'' above.)
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 described below.
Differences Between Service Bulletin and Proposed Rule
Although the service bulletin recommends accomplishing the
replacement ``at the next scheduled maintenance period when manpower,
materials, and facilities are available,'' the FAA has determined that
such an imprecise compliance time would not address the identified
unsafe condition in a timely manner. In developing an appropriate
compliance time for this proposed action, 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 perform the
replacement. In light of all of these factors, the FAA finds that a
compliance time of 18 months for completing the proposed actions to be
warranted, in that it represents an appropriate interval of time for
affected airplanes to continue to operate without compromising safety.
Changes to 14 CFR Part 39/Effect on the Proposed AD
On July 10, 2002, the FAA issued a new version of 14 CFR part 39
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness
directives system. The regulation now includes material that relates to
altered products, special flight permits, and alternative methods of
compliance (AMOCs). Because we have now included this material in part
39, only the office authorized to approve AMOCs is identified in each
individual AD.
Change to Labor Rate Estimate
We have reviewed the figures we have used over the past several
years to calculate AD costs to operators. To account for various
inflationary costs in the airline industry, we find it necessary
[[Page 54686]]
to increase the labor rate used in these calculations from $60 per work
hour to $65 per work hour. The cost impact information, below, reflects
this increase in the specified hourly labor rate.
Cost Impact
There are approximately 2,919 airplanes of the affected design in
the worldwide fleet. The FAA estimates that 1,129 airplanes of U.S.
registry would be affected by this proposed AD. The FAA estimates that
it would take approximately 2 work hours for each airplane specified as
Group 1 in the referenced service bulletin, and approximately 1 work
hour for each airplane specified as Group 2 in the referenced service
bulletin, to accomplish the proposed actions; the average labor rate is
estimated to be $65 per work hour. Parts and materials are standard and
are to be supplied by the operator. Based on these figures, the cost
impact of the proposed AD on U.S. operators is estimated to be $130 per
Group 1 airplane, and $65 per Group 2 airplane.
The cost impact figures discussed above are 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 proposed 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. The manufacturer may
cover the cost of replacement parts associated with this proposed AD,
subject to warranty conditions. Manufacturer warranty remedies may also
be available for labor costs associated with this proposed AD. As a
result, the costs attributable to the proposed AD may be less than
stated above.
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 2001-NM-156-AD.
Applicability: Model 737-100, -200, -200C, -300, -400, and -500
series airplanes, as listed in Boeing Service Bulletin 737-25-1434,
dated March 22, 2001; certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To prevent the latch cable assembly from disconnecting from the
latch block assembly of the door mounted escape slides, which could
result in an escape slide not deploying in an emergency situation,
accomplish the following:
Replacement
(a) Within 18 months after the effective date of this AD,
replace the existing screw, nut, and washers that attach the latch
cable assembly to the latch block assembly of the door mounted
escape slides, with the new, improved screw, nut, and washers; per
the Work Instructions of Boeing Service Bulletin 737-25-1434, dated
March 22, 2001.
Parts Installation
(b) As of the effective date of this AD, no person may install a
nut, part number (P/N) BACN10R10L, that was removed from any
airplane; or install a screw, P/N NAS623-3-8; on any airplane.
Alternative Methods of Compliance
(c)(1) In accordance with 14 CFR 39.19, the Manager, Seattle
Aircraft Certification Office (ACO), FAA, is authorized to approve
alternative methods of compliance (AMOC) for this AD.
(2) An AMOC that provides an acceptable level of safety may be
used for repair of the latch cable assembly and the latch block
assembly for the door mounted escape slide, if it is approved by a
Boeing Company Designated Engineering Representative (DER) who has
been authorized by the Manager, Seattle ACO, to make such findings.
Issued in Renton, Washington, on September 11, 2003.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 03-23822 Filed 9-17-03; 8:45 am]
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