[Federal Register Volume 64, Number 134 (Wednesday, July 14, 1999)]
[Proposed Rules]
[Pages 37918-37920]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-17859]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-134-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-600, -700, and -800
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 737-600, -
700, and -800 series airplanes. This proposal would require
installation of a drain at each of the number 2 window frame assemblies
in the airplane. This proposal is prompted by reports that flight deck
emergency exits (number 2 windows) were found frozen shut after
landing. The actions specified by the proposed AD are intended to
prevent water accumulation in the lower corners of the flight deck
emergency exits (number 2 windows), which can freeze and prevent the
exits from being used during an emergency evacuation.
DATES: Comments must be received by August 30, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-134-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: Meghan Gordon, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-2207; 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
[[Page 37919]]
statement is made: ``Comments to Docket Number 99-NM-134-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-134-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received reports indicating that flight deck emergency
exits (number 2 windows) were found frozen shut after landing on Boeing
Model 737-600, -700, and -800 series airplanes. The design allows water
to accumulate in the lower corner of the number 2 window, which can
freeze, preventing the window from opening. This condition, if not
corrected, could result in the flight deck emergency exits being
unusable by the flight deck occupants during an emergency evacuation.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Service Bulletin 737-56-
1011, dated November 19, 1998, which describes procedures for
installation of a drain at each of the number 2 window frame assemblies
in the airplane. Accomplishment of the action 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 installation of a drain at each of the number
2 window frame assemblies. The actions would be required to be
accomplished in accordance with the service bulletin described
previously, except as discussed below.
Differences Between Proposed Rule and Service Bulletin
Operators should note that, although the service bulletin does not
specify a compliance time for accomplishment of installation of a drain
at each of the number 2 window frame assemblies in the airplane, this
proposal would require that action to be accomplished within 18 months
after the effective date of this AD. In developing an appropriate
compliance time for this proposed AD, the FAA considered the degree of
urgency associated with addressing the subject unsafe condition, the
average utilization of the affected fleet, and the time necessary to
accomplish the proposed actions (approximately 3 hours). In light of
these factors, the FAA finds a compliance time of 18 months for
accomplishing 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 144 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 57 airplanes of U.S. registry
would be affected by this proposed AD, that it would take approximately
3 work hours per airplane to accomplish the proposed actions, and that
the average labor rate is $60 per work hour. Required parts would cost
approximately $536 per airplane. Based on these figures, the cost
impact of the proposed AD on U.S. operators is estimated to be $40,812,
or $716 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 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 99-NM-134-AD.
Applicability: Model 737-600, -700, and -800 series airplanes;
line numbers 1 through 144 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 water accumulation in the lower corners of the flight
deck emergency exits (number 2 windows), which can freeze and
prevent the exits from being used during an emergency evacuation,
accomplish the following:
Installation
(a) Within 18 months after the effective date of this AD,
install a drain at each of the number 2 window frame assemblies in
the airplane in accordance with Boeing Service Bulletin 737-56-1011,
dated November 19, 1998.
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 2: Information concerning the existence of approved
alternative methods of
[[Page 37920]]
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 July 7, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-17859 Filed 7-13-99; 8:45 am]
BILLING CODE 4910-13-U
