[Federal Register Volume 64, Number 89 (Monday, May 10, 1999)]
[Proposed Rules]
[Pages 24963-24964]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-11617]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 64, No. 89 / Monday, May 10, 1999 / Proposed 
Rules  

[[Page 24963]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-253-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -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 737-100, -
200, -300, -400, and -500 series airplanes. This proposal would require 
repetitive inspections to detect damage of certain taxi light 
assemblies, and replacement with a new or serviceable part, if 
necessary. This proposal also would require eventual replacement of 
certain taxi light assemblies with improved parts, which would 
constitute terminating action for the repetitive inspections. This 
proposal is prompted by a report that a damaged taxi light detached 
from an airplane and was ingested into the airplane engines. The 
actions specified by the proposed AD are intended to prevent damage to 
the taxi light assembly, which could result in detachment of the taxi 
light assembly from the airplane, ingestion of taxi light debris into 
an engine, and consequent loss of thrust from one or both engines.

DATES: Comments must be received by June 24, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-253-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.

FOR FURTHER INFORMATION CONTACT: David Herron, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane 
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, 
SW., Renton, Washington 98055-4056; telephone (425) 227-2672; 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 98-NM-253-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. 98-NM-253-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports indicating that certain taxi light 
assemblies mounted on the nose landing gear assemblies of certain 
Boeing Model 737-100, -200, -300, -400, and -500 series airplanes have 
been found to be damaged. That damage has been attributed to contact 
between the light assembly and the tow bar during towing operations. 
Such contact occurs due to the proximity of the taxi lights to the 
fitting for towing operations. In one incident, a damaged taxi light 
assembly detached from the airplane, and debris from the taxi light 
assembly was ingested into both engines of a Boeing Model 737 series 
airplane during takeoff. That ingestion resulted in a loss of thrust, 
which forced the flightcrew to make an emergency landing. A damaged 
taxi light assembly, if not corrected, could result in detachment of 
the taxi light from the airplane, ingestion of taxi light debris into 
an engine, and consequent loss of thrust from one or both engines. Such 
loss of thrust could result in reduced controllability of the airplane.

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 repetitive detailed visual inspections to 
detect damage (including cracking, corrosion, deformation, or evidence 
of impact) of certain taxi light assemblies, and replacement with a new 
or serviceable part, if necessary. The proposed AD also would require 
eventual replacement of certain taxi light assemblies with improved 
parts, which would constitute terminating action for the repetitive 
inspections. The actions are required to be accomplished in accordance 
with the applicable maintenance manual.

Cost Impact

    There are approximately 2,857 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 1,159 airplanes of U.S. 
registry would be affected by this proposed AD.
    It would take approximately 1 work hour 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 proposed inspection on 
U.S. operators is estimated to be $69,540, or $60 per airplane, per 
inspection cycle.
    It would take approximately 2 work hours per airplane to accomplish 
the proposed replacement, at an average

[[Page 24964]]

labor rate of $60 per work hour. Required parts would cost 
approximately $549 per airplane. Based on these figures, the cost 
impact of the proposed replacement on U.S. operators is estimated to be 
$775,371, or $669 per 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 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 98-NM-253-AD.

    Applicability: Model 737-100, -200, -300, -400, and -500 series 
airplanes; that are not equipped with a Grimes Aerospace taxi light 
assembly having part number (P/N) 50-0199-9, 50-0199-11, 50-0128-1A, 
50-0128-1MA, 50-0128-3A, or 50-0128-3MA; 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 (d) 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 damage to the taxi light assembly, which could result 
in detachment of the taxi light from the airplane, ingestion of taxi 
light debris into an engine, and consequent loss of thrust from one 
or both engines; accomplish the following:

Initial and Repetitive Inspections

    (a) Within 60 days after the effective date of this AD, perform 
a detailed visual inspection to detect damage (including cracking, 
corrosion, deformation, or evidence of impact) of the taxi light 
assembly mounted on the nose landing gear of the airplane. Repeat 
the inspection thereafter at intervals not to exceed 1 day, until 
the requirements of paragraph (c) have been accomplished.

    Note 2: For the purposes of this AD, a detailed visual 
inspection is defined as an intensive visual inspection 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 lighting at an 
intensity deemed appropriate by the inspector. Inspection aids such 
as mirrors, magnifying glasses, etc., may be used. Surface cleaning 
and elaborate access procedures may be necessary.

Replacement

    (b) If any damage of the taxi light assembly is detected during 
any inspection performed in accordance with paragraph (a) of this 
AD, prior to further flight, replace the existing taxi light 
assembly with a new or serviceable taxi light assembly in accordance 
with the applicable maintenance manual. If the existing taxi light 
assembly is replaced with a Grimes Aerospace taxi light assembly 
having P/N 50-0199-9, 50-0199-11, 50-0128-1A, 50-0128-1MA, 50-0128-
3A, or 50-0128-3MA: no further action is required by this AD.

Terminating Action

    (c) Within 2 years after the effective date of this AD: Replace 
the existing taxi light assembly with a Grimes Aerospace taxi light 
assembly having P/N 50-0199-9, 50-0199-11, 50-0128-1A, 50-0128-1MA, 
50-0128-3A, or 50-0128-3MA; in accordance with the applicable 
maintenance manual. Such replacement constitutes terminating action 
for the repetitive inspection requirement of paragraph (a) of this 
AD.

Alternative Methods of Compliance

    (d) 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

    (e) Special flight permits may be issued in accordance with 
Secs. 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 3, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-11617 Filed 5-7-99; 8:45 am]
BILLING CODE 4910-13-U