

[Federal Register: September 20, 2007 (Volume 72, Number 182)]
[Proposed Rules]               
[Page 53704-53706]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr20se07-17]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-29257; Directorate Identifier 2007-NM-144-AD]
RIN 2120-AA64

 
Airworthiness Directives; Bombardier Model CL-600-2B19 (Regional 
Jet Series 100 & 440) 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 certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 
440) airplanes. This proposed AD would require repetitive detailed 
inspections for cracking of the left side and right side frame and 
reinforcement angles at fuselage station (FS) 640 between stringer 9 
and stringer 12, and corrective actions if necessary. This proposed AD 
results from reports that cracks have been discovered on the frame and 
reinforcement angles at FS 640. We are proposing this AD to detect and 
correct cracking of the frame, which could lead to failure of the 
fuselage structure and possible loss of the airplane.

DATES: We must receive comments on this proposed AD by October 22, 
2007.

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: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room W12-140 on the ground floor of the 
West Building, 1200 New Jersey Avenue, SE., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, 
Station Centre-ville, Montreal, Quebec H3C 3G9, Canada, for service 
information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT: Pong K. Lee, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New 
York 11590; telephone (516) 228-7324; fax (516) 794-5531.

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-2007-
29257; Directorate Identifier 2007-NM-144-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, 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 Operations office between 9 

a.m. and 5 p.m., Monday through Friday, except Federal holidays. The 
Docket Operations office (telephone (800) 647-5527) is located on the 
ground level of the West 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.

[[Page 53705]]

Discussion

    Transport Canada Civil Aviation (TCCA), which is the airworthiness 
authority for Canada, notified us that an unsafe condition may exist on 
certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) 
airplanes. TCCA advises that cracks have been discovered on the frame 
and reinforcement angles at fuselage station (FS) 640 on a number of 
CRJ (Canadair Regional Jet) airplanes. This condition, if not 
corrected, could result in failure of the fuselage structure and 
possible loss of the airplane.

Relevant Service Information

    Bombardier has issued Alert Service Bulletin 601R-53-061, Revision 
E, dated December 7, 2006. The alert service bulletin describes 
procedures for doing repetitive detailed visual inspections for 
cracking of the frame at fuselage station (FS) 640 between stringer 9 
and stringer 12 (Part A of the Accomplishment Instructions) and, if 
necessary, corrective actions as follows:
     Repair as described in Part A of the Accomplishment 
Instructions;
     Install a modification, including related investigative 
and corrective actions; or
     Contact Bombardier for repair instructions.

The related investigative and corrective actions of the modification 
(Part C of the Accomplishment Instructions) include cutting out a 
section of the flange frame at FS640 then doing a liquid penetrant or 
eddy current inspection for cracking of the skin doubler, and 
contacting Bombardier for repair instructions. Accomplishing the 
actions specified in the service information is intended to adequately 
address the unsafe condition. TCCA mandated the service information and 
issued Canadian airworthiness directive CF-2003-12, dated May 7, 2003, 
to ensure the continued airworthiness of these airplanes in Canada.

FAA's Determination and Requirements of the Proposed AD

    These airplanes are manufactured in Canada and are type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, TCCA has kept the FAA informed of 
the situation described above. We have examined TCCA'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 under ``Differences Between 
the Proposed AD and Bombardier Alert Service Bulletin/Canadian 
Airworthiness Directive.''

Differences Between the Proposed AD and Bombardier Alert Service 
Bulletin/Canadian Airworthiness Directive

    The Canadian airworthiness directive specifies that Bombardier 
Alert Service Bulletin 601R-53-061, Revision B, dated February 20, 
2003, or later revisions, must be used to do all described inspections 
and actions. However, we have determined that Revision E, dated 
December 7, 2006, of the alert service bulletin no longer contains 
certain actions described by Revision B. Therefore, this proposed AD 
would require doing all actions in accordance with Alert Service 
Bulletin 601R-53-061, Revision E, dated December 7, 2006. This 
difference has been coordinated with TCCA.
    In this proposed AD, the ``detailed visual inspection'' specified 
in the Bombardier alert service bulletin and Canadian airworthiness 
directive is referred to as a ``detailed inspection.'' We have included 
the definition for a detailed inspection in a note in the proposed AD.
    The Bombardier alert service bulletin and Canadian airworthiness 
directive specify to contact Bombardier for instructions on how to 
repair certain conditions, but this proposed AD would require repairing 
those conditions using a method approved by the FAA or TCCA (or its 
delegated agent). 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 approved by the FAA or TCCA (or its delegated agent) would 
be acceptable for compliance with this proposed AD.
    Although the Accomplishment Instructions of the alert service 
bulletin describe procedures for submitting certain information to the 
manufacturer, this proposed AD would not require that action.

Interim Action

    We consider this proposed AD interim action. If final action is 
later identified, we might consider further rulemaking then.

Costs of Compliance

    This proposed AD would affect about 739 airplanes of U.S. registry. 
The proposed inspection would take about 2 work hours per airplane, at 
an average labor rate of $80 per work hour. Based on these figures, the 
estimated cost of the proposed AD for U.S. operators is $118,240, or 
$160 per airplane, per inspection cycle.

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 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.

[[Page 53706]]

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):

Bombardier, Inc. (Formerly Canadair): Docket No. FAA-2007-29257; 
Directorate Identifier 2007-NM-144-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by November 
5, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier Model CL-600-2B19 (Regional 
Jet Series 100 & 440) airplanes, certificated in any category; as 
identified in Bombardier Alert Service Bulletin 601R-53-061, 
Revision E, dated December 7, 2006.

Unsafe Condition

    (d) This AD results from reports that cracks have been 
discovered on the frame and reinforcement angles at fuselage station 
(FS) 640. Failure of this frame could degrade the structural 
integrity of the airplane. We are issuing this AD to detect and 
correct cracking of the frame, which could lead to failure of the 
fuselage structure and possible loss 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.

Service Bulletin Reference

    (f) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of Bombardier Alert Service Bulletin 
601R-53-061, Revision E, dated December 7, 2006.

Detailed Inspection

    (g) Before the accumulation of 8,600 total flight cycles or 
within 1,100 flight cycles after the effective date of this AD, 
whichever occurs later: Perform a detailed inspection to detect 
cracking of the left side and right side frames and reinforcement 
angles at FS640 between stringer 9 and stringer 12, in accordance 
with Part A of the Accomplishment Instructions of the service 
bulletin.

    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.''

Repetitive Inspection and Corrective Action

    (h) If no crack is found during the inspection required by 
paragraph (g) of this AD: Repeat the detailed inspection thereafter 
at intervals not to exceed 1,100 flight cycles, until the frame 
modification described in paragraph (i)(2) of this AD has been done.
    (i) If any crack is found during the inspection required by 
paragraph (g) of this AD: Before further flight, repair the crack in 
accordance with paragraph (i)(1), (i)(2), or (i)(3) of this AD, as 
applicable.
    (1) For any crack found in the frame at the stringer 9 cut-out 
only, repair in accordance with Part A of the Accomplishment 
Instructions of the service bulletin.
    (2) For any crack found in the frame reinforcement doubler only: 
Do the frame modification (including related investigative and 
corrective actions) described in Part C of the Accomplishment 
Instructions of the service bulletin, except where the alert service 
bulletin specifies to contact the manufacturer for repair 
instructions, repair the crack using a method approved by either the 
Manager, New York Aircraft Certification Office (ACO), FAA; or 
Transport Canada Civil Aviation (TCCA) (or its delegated agent); 
then do the detailed inspection required by paragraph (j) of this 
AD.
    (3) For any crack found in areas of the inspection zone 
described in paragraph (g) of this AD other than those described in 
paragraphs (i)(1) and (i)(2) of this AD: Repair the crack using a 
method approved by either the Manager, New York ACO, FAA; or TCCA 
(or its delegated agent).

Repetitive Inspection After Frame Modification

    (j) Within 12,000 flight cycles after doing the modification 
described in paragraph (i)(2) of this AD, do the detailed inspection 
required by paragraph (g) of this AD. Repeat the detailed inspection 
thereafter at intervals not to exceed 1,100 flight cycles.

No Reporting Requirement

    (k) Although the alert service bulletin referred to in this AD 
specifies to submit certain information to the manufacturer, this AD 
does not include that requirement.

Alternative Methods of Compliance (AMOCs)

    (l)(1) The Manager, New York ACO, FAA, has the authority to 
approve AMOCs for this AD, if requested in accordance with the 
procedures found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.

Related Information

    (m) Canadian airworthiness directive CF-2003-12, dated May 7, 
2003, also addresses the subject of this AD.

    Issued in Renton, Washington, on September 12, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-18539 Filed 9-19-07; 8:45 am]

BILLING CODE 4910-13-P
