[Federal Register Volume 59, Number 95 (Wednesday, May 18, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-12124]


[[Page Unknown]]

[Federal Register: May 18, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-36-AD]

 

Airworthiness Directives; Aerospatiale Model ATR72-100 and -200 
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 Model ATR72-100 and -200 
series airplanes. This proposal would require a one-time dye penetrant 
inspection to detect cracking in certain hinge pins of the nose landing 
gear (NLG), and replacement of cracked pins with crack-free pins. This 
proposal is prompted by reports of cracking of certain hinge pins in 
the NLG. The actions specified by the proposed AD are intended to 
prevent collapse of the NLG due to cracking of the hinge pins.

DATES: Comments must be received by July 15, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-36-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.
    The service information referenced in the proposed rule may be 
obtained from Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 
03, France. This information may be examined at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Sam Grober, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-1187; fax (206) 227-1320.

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 94-NM-36-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-103, Attention: Rules 
Docket No. 94-NM-36-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Direction General de l'Aviation Civile (DGAC), which is the 
airworthiness authority for France, recently notified the FAA that an 
unsafe condition may exist on certain Aerospatiale Model ATR72-100 and 
-200 series airplanes. The DGAC advises that cracking has been found on 
the hinge pins during routine overhaul of the nose landing gear (NLG) 
on Model ATR72-100 and -200 series airplanes. The cause for this 
cracking has been attributed to improper heat treatment during 
manufacture of the hinge pins. The defective pins have been isolated to 
those manufactured by Nardi having part number D56867 and serial 
numbers beginning with the letter ``N.'' This condition, if not 
corrected, could result in collapse of the NLG due to cracking of the 
hinge pins.
    Avions de Transport Regional has issued Service Bulletin ATR72-32-
1021, dated January 17, 1994, that describes procedures for a one-time 
dye penetrant inspection to detect cracking in certain hinge pins of 
the NLG, and replacement of cracked pins with crack-free pins. The DGAC 
classified this service bulletin as mandatory and issued French 
Airworthiness Directive 94-002-019(B), dated January 5, 1994, in order 
to assure the continued airworthiness of these airplanes in France.
    This airplane model is manufactured in France and is type 
certificated for operation in the United States under the provisions of 
Sec. 21.29 of the Federal Aviation Regulations and the applicable 
bilateral airworthiness agreement. Pursuant to this bilateral 
airworthiness agreement, the DGAC has kept the FAA informed of the 
situation described above. The FAA has examined the findings of the 
DGAC, reviewed all available information, and determined that AD action 
is necessary for products of this type design that are certificated for 
operation in the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, the proposed AD would require a one-time dye 
penetrant inspection to detect cracking in certain hinge pins in the 
NLG, and replacement of cracked pins with crack-free pins. The actions 
would be required to be accomplished in accordance with the service 
bulletin described previously.
    The FAA estimates that 28 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 6 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $55 per work hour. Based on these figures, the 
total cost impact of the proposed AD on U.S. operators is estimated to 
be $9,240, or $330 per airplane.
    The total 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.
    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 14 
CFR part 39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES-

    -1. The authority citation for part 39 continues to read as 
follows:


    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    -2. Section 39.13 is amended by adding the following new 
airworthiness directive:


Aerospatiale: Docket 94-NM-36-AD.

    Applicability: Model ATR72-100 and -200 series airplanes 
equipped with hinge pins installed at the nose landing gear (NLG) 
that are manufactured by Nardi, have part number D56867, and have 
serial numbers beginning with the letter ``N''; certificated in any 
category.
    Compliance: Required as indicated, unless accomplished 
previously.
    -To prevent collapse of the NLG due to cracking of the hinge 
pins, accomplish the following:
    -(a) Prior to the accumulation of 10,000 total landings or 
within 1,000 landings after the effective date of this AD, whichever 
occurs later, perform a dye penetrant inspection to detect cracking 
in the hinge pins of the NLG in accordance with Avions de Transport 
Regional Service Bulletin ATR72-32-1021, dated January 17, 1994.
    -(1) If no cracking is found, prior to further flight, reinstall 
that hinge pin in accordance with the service bulletin.
    -(2) If cracking is found, prior to further flight, install a 
new hinge pin or a pin that has been previously inspected and found 
to be crack-free, in accordance with the service bulletin.
    -(b) As of the effective date of this AD, no hinge pin 
manufactured by Nardi having part number D56867 and any serial 
number beginning with the letter ``N,'' shall be installed on the 
NLG of any airplane, unless that pin has been previously inspected 
and has been found to be crack-free, in accordance Avions de 
Transport Regional Service Bulletin ATR72-32-1021, dated January 17, 
1994.
    -(c) 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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (d) Special flight permits may be issued in accordance with 
Federal Aviation Regulations (FAR) 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 12, 1994. Original signed 
by:
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-12124 Filed 5-17-94; 8:45 am]
BILLING CODE 4910-13-U