[Federal Register Volume 68, Number 82 (Tuesday, April 29, 2003)]
[Proposed Rules]
[Pages 22641-22644]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-10514]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-419-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 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 all Boeing Model 747 series 
airplanes. This proposal would require a one-time inspection to 
determine whether the outer cylinder of the wing landing gear

[[Page 22642]]

has certain part numbers, and replacement of the outer cylinder of the 
wing landing gear with a new, improved, or reworked part if necessary. 
This proposal also would require removal of the load evening system, if 
such a system is installed. This action is necessary to prevent 
fracture of the outer cylinder of the wing landing gear, which could 
result in collapse of the wing landing gear. This action is intended to 
address the identified unsafe condition.

DATES: Comments must be received by June 13, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-419-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: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-419-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 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: Tamara Anderson, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6421; 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 2000-NM-419-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-419-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report indicating that the wing landing gear 
on a Boeing Model 747-300 series airplane collapsed while the airplane 
was turning onto a runway. Investigation revealed that the outer 
cylinder of the wing landing gear was fractured. We have received 
additional reports of air leaking from the wing landing gear, due to 
fracture of the outer cylinder, on certain Model 747 series airplanes. 
Fracture of the outer cylinder has been attributed to cracks caused by 
heat damage on the inner surface of the outer cylinder that resulted 
from machining at the top of the outer cylinder during production or 
overhaul. Chrome plating was applied at the top of the outer cylinder 
to be used by a piston in the load evening system that was installed on 
early Model 747 series airplanes. Later Model 747 series airplanes were 
not equipped with a load evening system because Boeing determined the 
system was unnecessary. However, certain airplanes not equipped with a 
load evening system were delivered with chrome plating on the outer 
cylinder. Cracking or heat damage of the outer cylinder of the wing 
landing gear, if not corrected, could lead to fracture of the outer 
cylinder of the wing landing gear, which could result in collapse of 
the wing landing gear.
    The outer cylinder of the wing landing gear is interchangeable 
among all Model 747 series airplanes, except certain Model 747-400 
series airplanes that are certificated to a maximum airplane taxi 
weight of 913 kilo-pounds (kips). Therefore, any Model 747 series 
airplane, except such Model 747-400 series airplanes, may have the 
subject outer cylinders installed and may be subject to the same unsafe 
condition.

Explanation of Relevant Service Information

    We have reviewed and approved Boeing Service Bulletin 747-32-2472, 
dated November 30, 2000, which describes procedures for a one-time 
inspection to determine whether the outer cylinder of the wing landing 
gear has certain part numbers. For airplanes with the affected part 
numbers, the service bulletin recommends replacement of the existing 
outer cylinder with a new, improved, or reworked part. The procedures 
for rework, if accomplished, include the following:
    [sbull] A nital etch inspection of the inner surface of the upper 
end of the outer cylinder for the presence of chrome plating.
    [sbull] Removal of any chrome plating that is found.
    [sbull] A magnetic particle inspection for cracking of the outer 
cylinder.
    [sbull] A nital etch inspection for heat damage of the outer 
cylinder.
    [sbull] Rework of the outer cylinder to remove any crack or heat 
damage.
    [sbull] Changing the part number of the outer cylinder.
    Accomplishment of the actions specified in Boeing Service Bulletin 
747-32-2472 is intended to adequately address the identified unsafe 
condition.
    Boeing Service Bulletin 747-32-2472 recommends accomplishment of 
Boeing Service Bulletin 747-32-2131 concurrently with the actions in 
Boeing Service Bulletin 747-32-2472. We have reviewed and approved 
Boeing Service Bulletin 747-32-2131, Revision 2, dated March 15, 1974, 
which describes procedures for removal of the load evening system 
installed on the wing landing gear.

[[Page 22643]]

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 bulletins described previously.

Clarification of Applicability Statement

    We stated previously that the outer cylinder of the wing landing 
gear is interchangeable among all Model 747 series airplanes, except 
certain Model 747-400 series airplanes certificated to a maximum 
airplane taxi weight of 913 kips. However, those airplanes do not have 
a separate model designation from other Model 747-400 series airplanes. 
Therefore, this proposed AD would apply to all Model 747 series 
airplanes.

Cost Impact

    There are approximately 1,106 airplanes of the affected design in 
the worldwide fleet. We estimate that 256 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 to 
determine whether subject part numbers are installed, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of this proposed inspection on U.S. operators is estimated to be 
$15,360, or $60 per airplane.
    We estimate that 225 airplanes in the worldwide fleet, and 66 
airplanes of U.S. registry, are equipped with the subject outer 
cylinders that would require further action. It would take 
approximately 12 work hours per airplane to accomplish the proposed 
chrome removal and inspections for cracking or heat damage, at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of these proposed actions on U.S. operators is estimated to 
be $47,520, or $720 per airplane.
    For airplanes subject to removal of the load evening system, it 
would take approximately 240 work hours per airplane to accomplish, at 
an average labor rate of $60 per work hour. Based on the best data 
available, we estimate that necessary parts would cost $2,392. Based on 
these figures, the cost impact of the proposed removal of the load 
evening system is estimated to be $16,792 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 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.

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-419-AD.

    Applicability: All Model 747 series airplanes, 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 (e) 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 fracture of the outer cylinder of the wing landing 
gear, which could result in collapse of the wing landing gear, 
accomplish the following:

Inspection to Determine Part Number

    (a) Within 36 months after the effective date of this AD, 
perform a one-time inspection to determine the part number of the 
outer cylinder of the wing landing gear on both sides of the 
airplane, per the Accomplishment Instructions of Boeing Service 
Bulletin 747-32-2472, excluding Evaluation Form, dated November 30, 
2000.
    (1) If no outer cylinder having part number (P/N) 65B01212-( ) 
(where ``( )'' is any dash number of that part number), 65B01430-3, 
or 65B01430-4 is found: No further action is required by this 
paragraph.
    (2) If any outer cylinder having P/N 65B01212-( ) (where ``( )'' 
is any dash number of that part number), 65B01430-3, or 65B01430-4 
is found: Accomplish paragraph (b) of this AD.

Replacement of Outer Cylinder

    (b) For any outer cylinder identified in paragraph (a)(2) of 
this AD: Within 36 months after the effective date of this AD, 
replace the outer cylinder on the wing landing gear with a new, 
improved part or a part that has been inspected and reworked per the 
Accomplishment Instructions of Boeing Service Bulletin 747-32-2472, 
excluding Evaluation Form, dated November 30, 2000. The rework 
procedures described in the service bulletin, if accomplished, 
include performing a one-time nital etch inspection of the upper 
inner surface of the outer cylinder for chrome plating; removing any 
chrome plating that is present; performing a one-time magnetic 
particle inspection for cracking of the outer cylinder; performing a 
nital etch inspection for heat damage of the outer cylinder; 
reworking the outer cylinder, as applicable; and changing the part 
number of the outer cylinder.

Removal of the Load Evening System

    (c) For airplanes listed in Boeing Service Bulletin 747-32-2131, 
Revision 2, dated March 15, 1974: Before performing the requirements 
of paragraph (b) of this AD, remove the load evening system 
installed on the wing landing gear, per the Accomplishment 
Instructions of the service bulletin.

[[Page 22644]]

Parts Installation

    (d) As of the effective date of this AD, no person may install, 
on any airplane, an outer cylinder of the wing landing gear if the 
outer cylinder has P/N 65B01212-( ) (where ``( )'' is any dash 
number of that part number), 65B01430-3, or 65B01430-4.

Alternative Methods of Compliance

    (e) 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. 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 compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (f) Special flight permits may be issued in accordance with 
Sec. Sec.  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 April 23, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-10514 Filed 4-28-03; 8:45 am]
BILLING CODE 4910-13-P