[Federal Register Volume 63, Number 72 (Wednesday, April 15, 1998)]
[Proposed Rules]
[Pages 18341-18342]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-9877]


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 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.
 
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  Federal Register / Vol. 63, No. 72 / Wednesday, April 15, 1998 / 
Proposed Rules  

[[Page 18341]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-254-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 certain Boeing Model 747 series 
airplanes. This proposal would require a one-time detailed visual 
inspection of the outboard sequence carriage attachment fitting for the 
presence and condition of a shim, and follow-on corrective actions, if 
necessary. This proposal is prompted by a report that a piece of the 
left wing inboard foreflap came off during a landing approach. The 
actions specified by the proposed AD are intended to prevent the 
failure of the outboard sequence carriage fitting, which could allow 
the wing inboard foreflap to separate and penetrate the fuselage, 
possibly injuring passengers and crewmembers.

DATES: Comments must be received by June 1, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-254-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: Tamara L. Dow, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2771; 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 97-NM-254-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. 97-NM-254-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report indicating that a piece of the left 
wing inboard foreflap came off a Boeing Model 747-200 series airplane 
during a landing approach and hit the airplane at body stations 1800 
through 1840. The damages that occurred were skin punctures, stringer 
fractures, frame fractures, and the movement of one passenger window. 
This airplane had an overhauled foreflap that did not have a shim 
installed between the outboard sequence carriage attachment fitting and 
the left wing inboard foreflap. The outboard sequence carriage 
attachment fitting is designed to absorb all side-to-side loads on the 
inboard foreflap. There is a shim installed on the horizontal flange of 
the fitting, and there are four bolts that attach this horizontal 
flange to the foreflap. The shim is installed, to prevent a gap of more 
the 0.003 inch between the fitting and the foreflap. If a shim is not 
installed or if the incorrect grip lengths of fasteners are used, the 
outboard sequence carriage attachment fitting can move due to incorrect 
clamp-up. This condition, if not corrected, could result in the failure 
of the outboard sequence carriage fitting, which could allow the wing 
inboard foreflap to separate and penetrate the fuselage, possibly 
injuring passengers and crewmembers.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
747-57A2302, dated April 10, 1997, which describes procedures for a 
one-time detailed visual inspection of the outboard sequence carriage 
attachment fitting for the presence and condition of a shim, and 
follow-on corrective actions, if necessary. The follow-on actions 
include; replacing any shim that has migrated or is missing with a new 
or serviceable part; performing a high frequency eddy current 
inspection for cracking on the fastener holes in the fitting, the 
foreflap lower spar chord, and on the fitting flange; and replacing 
cracked or damaged fittings with new or serviceable parts. 
Accomplishment of the actions specified in the alert 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

[[Page 18342]]

require accomplishment of the actions specified in the alert service 
bulletin described previously.

Cost Impact

    There are approximately 1,147 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 311 airplanes of U.S. 
registry would be affected by this proposed AD, that it would take 
approximately 1 work hour per airplane to accomplish the proposed 
inspection, and that the average labor rate is $60 per work hour. Based 
on these figures, the cost impact of the proposed AD on U.S. operators 
is estimated to be $18,660, or $60 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 97-NM-254-AD.

    Applicability: Model 747-100, 747-200B, 747-200F, 747-200C, 
747SR, 47-100B, 747-300, 747-100B SUD, 747-400, 747-400D, and 747-
400F series airplanes, having line numbers 1 through 1122 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 the failure of the outboard sequence carriage 
fitting, which could allow the wing inboard foreflap to separate and 
penetrate the fuselage, possibly injuring passengers and 
crewmembers, accomplish the following:
    (a) Within 1,500 landings or 18 months after the effective date 
of this AD, whichever occurs first, perform a one-time detailed 
visual inspection of the outboard sequence carriage attachment 
fitting for the presence and condition of a shim, and follow-on 
corrective actions, if necessary, in accordance with Boeing Alert 
Service Bulletin 747-57A2302, dated April 10, 1997.
    (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 compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (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 April 8, 1998.
John J. Hickey,
Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-9877 Filed 4-14-98; 8:45 am]
BILLING CODE 4910-13-U