[Federal Register Volume 71, Number 26 (Wednesday, February 8, 2006)]
[Proposed Rules]
[Pages 6413-6415]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-1685]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-23816; Directorate Identifier 2005-NM-247-AD]
RIN 2120-AA64


Airworthiness Directives; Aerospatiale Model ATR42 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all Aerospatiale Model ATR42 airplanes. This proposed AD would 
require one-time inspections to detect discrepancies (e.g., cracking, 
loose/sheared fasteners, distortion) of the upper skin and rib feet of 
the outer wing boxes, and repair if necessary. This proposed AD results 
from a report of cracking on the upper skin and ribs of the outer wing 
box on an in-service airplane. We are proposing this AD to detect and 
correct these discrepancies, which could result in reduced structural 
integrity of the airplane.

DATES: We must receive comments on this proposed AD by March 10, 2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 
03, France, for service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT: Tom Rodriguez, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-1137; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``FAA-2006-
23816; Directorate Identifier 2005-NM-247-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association,

[[Page 6414]]

business, labor union, etc.). You may review the DOT's complete Privacy 
Act Statement in the Federal Register published on April 11, 2000 (65 
FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

Discussion

    The Direction G[eacute]n[eacute]rale de l'Aviation Civile (DGAC), 
which is the airworthiness authority for France, notified us that an 
unsafe condition may exist on all Aerospatiale Model ATR42 airplanes. 
The DGAC advises that cracking has been found on the upper skin and 
ribs of the outer wing box on an in-service airplane. This condition, 
if not corrected, could result in reduced structural integrity of the 
airplane.

Relevant Service Information

    Aerospatiale has issued Avions de Transport Regional Service 
Bulletin ATR42-57-0064, dated December 16, 2004. The service bulletin 
describes procedures for doing an external detailed visual inspection 
for discrepancies of the upper skin panels of the outer wing box on the 
left and right wing, from rib 24 to rib 29. Discrepancies include 
cracking of the skin, cracked sealant, loose/sheared fasteners, and 
distortion. The service bulletin also describes procedures for doing an 
internal inspection following the external inspection. The internal 
inspection is to look for discrepancies of the rib feet from rib 24 to 
rib 29 and is conducted using one of two inspection methods: A 
borescopic inspection through access doors, or a detailed visual 
inspection after removing the leading edge of the wing. The service 
bulletin also describes procedures for sending inspection results to 
the manufacturer, and repairing any discrepancies using an ``approved 
solution.'' Accomplishing the actions specified in the service 
information is intended to adequately address the unsafe condition. The 
DGAC mandated the service information and issued French airworthiness 
directive F-2004-191, dated December 22, 2004, to ensure the continued 
airworthiness of these airplanes in France.

FAA's Determination and Requirements of the Proposed AD

    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 (14 CFR 21.29) and the 
applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, the DGAC has kept the FAA informed 
of the situation described above. We have examined the DGAC's findings, 
evaluated all pertinent information, and determined that we need to 
issue an AD for airplanes of this type design that are certificated for 
operation in the United States.
    Therefore, we are proposing this AD, which would require 
accomplishing the actions specified in the service information 
described previously, except as discussed in ``Differences Between the 
Proposed AD, the Service Bulletin, and the French Airworthiness 
Directive.''

Differences Between the Proposed AD, the Service Bulletin, and the 
French Airworthiness Directive

    The French airworthiness directive and the service bulletin specify 
to contact the manufacturer for an approved solution for repairing 
discrepancies found during the internal inspection; and do not specify 
that repairs are required if discrepancies are found during the 
external inspection. This proposed AD would require repairing those 
conditions using a method that we or the DGAC (or its delegated agent) 
approve. In light of the type of repair that would be required to 
address the unsafe condition, and consistent with existing bilateral 
airworthiness agreements, we have determined that, for this proposed 
AD, a repair we or the DGAC approve would be acceptable for compliance 
with this proposed AD.
    The French airworthiness directive and the service bulletin specify 
to submit certain information to the manufacturer, this proposed AD 
does not include that requirement.

Clarification of Inspection Language

    The French airworthiness directive and the service bulletin specify 
doing a detailed visual inspection for discrepancies. In this proposed 
AD we refer to this inspection as a ``detailed inspection.'' Note 1 of 
this proposed AD defines a detailed inspection.

Costs of Compliance

    This proposed AD would affect about 14 airplanes of U.S. registry. 
The proposed actions would take about 6 work hours per airplane if the 
internal borescopic inspection method is chosen, and about 44 work 
hours per airplane if the internal detailed inspection method (with the 
leading edge removed) is chosen. Both estimates include the time 
necessary for the external detailed inspection. The average labor rate 
is $65 per work hour. Based on these figures, the estimated cost of the 
proposed AD for U.S. operators is between $5,460 and $40,040, or either 
$390 or $2,860 per airplane.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify that the 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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with

[[Page 6415]]

this proposed AD and placed it in the AD docket. See the ADDRESSES 
section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

Aerospatiale: Docket No. FAA-2006-23816; Directorate Identifier 
2005-NM-247-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by March 10, 
2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Aerospatiale Model ATR42-200, -300, -
320, and -500 airplanes, certificated in any category.

Unsafe Condition

    (d) This AD results from a report of cracking on the upper skin 
and ribs of the outer wing box on an in-service airplane. We are 
issuing this AD to detect and correct discrepancies (e.g., cracking, 
loose/sheared fasteners, distortion) of the upper skin and rib feet 
of the outer wing boxes, which could result in reduced structural 
integrity of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

External Inspection and Repair

    (f) Before the accumulation of 4,000 total flight cycles, or 
within 3 months after the effective date of this AD, whichever is 
later: Do an external detailed inspection for discrepancies of the 
upper skin panels of the outer wing box on the left and right wing, 
from rib 24 to rib 29. Do the inspection in accordance with Part A 
of the Accomplishment Instructions of Avions de Transport Regional 
Service Bulletin ATR42-57-0064, dated December 16, 2004.
    (1) If any discrepancy is found: Before further flight, do the 
actions in paragraphs (f)(1)(i) and (f)(1)(ii) of this AD.
    (i) Repair using a method approved by either the Manager, 
International Branch, ANM-116, Transport Airplane Directorate, FAA; 
or the Direction Ge[eacute]n[eacute]rale de l'Aviation Civile (DGAC) 
(or its delegated agent).
    (ii) Do the internal inspection in accordance with paragraph (g) 
of this AD.
    (2) If no discrepancy is found: Within 4 months after doing the 
external detailed inspection, do the internal inspection in 
accordance with paragraph (g) of this AD.

    Note 1: For the purposes of this AD, a detailed inspection is: 
``An intensive examination of a specific item, installation, or 
assembly to detect damage, failure, or irregularity. Available 
lighting is normally supplemented with a direct source of good 
lighting at an intensity deemed appropriate. Inspection aids such as 
mirror, magnifying lenses, etc., may be necessary. Surface cleaning 
and elaborate procedures may be required.''

Internal Inspection and Repair

    (g) At the applicable time specified in paragraph (f)(1)(ii) or 
(f)(2) of this AD: Inspect for discrepancies of the rib feet from 
rib 24 to rib 29 using one of the inspection methods specified in 
paragraph (g)(1) or (g)(2) of this AD. Do the inspection in 
accordance with Part B of the Accomplishment Instructions of Avions 
de Transport Regional Service Bulletin ATR42-57-0064, dated December 
16, 2004. If any discrepancy is found during any inspection required 
by this paragraph: Before further flight, repair using a method 
approved by either the Manager, International Branch, ANM-116, 
Transport Airplane Directorate, FAA; or the DGAC (or its delegated 
agent).
    (1) A borescopic inspection through access doors.
    (2) A detailed inspection after removing the leading edge of the 
wing.

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, International Branch, ANM-116, Transport 
Airplane Directorate, FAA, has the authority to approve AMOCs for 
this AD, if requested in accordance with the procedures found in 14 
CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

Related Information

    (i) French airworthiness directive F-2004-191, dated December 
22, 2004, also addresses the subject of this AD.

    Issued in Renton, Washington, on January 30, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-1685 Filed 2-7-06; 8:45 am]
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