[Federal Register Volume 71, Number 247 (Tuesday, December 26, 2006)]
[Proposed Rules]
[Pages 77312-77314]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-22043]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-26647; Directorate Identifier 2006-NM-194-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 inspections 
of the bolts that attach the exhaust nozzle to the aft engine flange to 
determine if any bolts are missing or fractured, and replacement of the 
existing bolts with new, improved bolts. This proposed AD results from 
reports of the engine exhaust nozzle and fairing departing from the 
airplane in flight due to missing attachment bolts. We are proposing 
this AD to detect and correct missing or fractured attachment bolts, 
which could lead to the loss of an engine exhaust nozzle during flight 
and consequent structural damage to the airplane and hazard to people 
or property on the ground. Damage to the airplane could cause the 
airplane to yaw and result in reduced controllability of the airplane.

DATES: We must receive comments on this proposed AD by January 25, 
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: 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 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: Rocco Viselli, 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) 228-7331; 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-2006-
26647; Directorate Identifier 2006-NM-194-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 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

    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 there have been three reported incidents 
of the engine exhaust nozzle and fairing departing from the airplane. 
One incident occurred in flight and the two other incidents occurred on 
the ground. TCCA has also received numerous ground reports of missing 
and loose bolts. Investigation has revealed that the bolts that attach 
the engine exhaust nozzle to the engine flange provide less than the 
necessary stress margins, which could lead to failure of the bolts. 
Missing or fractured attachment bolts could lead to loss of the engine 
exhaust nozzle during flight. This condition, if not corrected, could 
cause structural damage to the airplane when the engine exhaust nozzle 
departs from the airplane and could create a hazard to people or 
property on the ground. Damage to the airplane could cause the airplane 
to yaw and result in reduced controllability of the airplane.

Relevant Service Information

    Bombardier has issued Service Bulletin 601R-78-021, dated June 2, 
2006. The service bulletin describes procedures for doing repetitive 
detailed visual inspections of the bolts that attach the exhaust nozzle 
to the aft engine flange to determine if any bolts are missing or 
fractured. If any bolt is missing or fractured, the service bulletin 
specifies replacing the existing bolts that attach the exhaust nozzle 
to the aft engine flange with new, improved bolts. 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-2006-19, dated July 28, 
2006, to ensure the continued airworthiness of these airplanes in 
Canada.
    Bombardier Service Bulletin 601R-78-021 refers to Short Brothers 
Service Bulletin CF34-NAC-78-024, Revision 4, dated November 10, 2005, 
as an additional source of service information for accomplishment of 
the replacement.

FAA's Determination and Requirements of the Proposed AD

    This airplane model is manufactured in Canada and is 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

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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.

Clarification of Inspection Terminology

    The ``detailed visual inspection'' specified in the Bombardier 
service bulletin and Canadian airworthiness directive is referred to as 
a ``detailed inspection'' in this proposed AD. We have included the 
definition for a detailed inspection in a note in the proposed AD.

Costs of Compliance

    The following table provides the estimated costs for U.S. operators 
to comply with this proposed AD.

                                                                     Estimated Costs
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                                                                                                                   Number of U.S.-
              Action                  Work hours     Average labor           Parts            Cost per airplane      registered          Fleet cost
                                                     rate per hour                                                    airplanes
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Inspection, per inspection cycle..               2             $80  None..................  $160, per inspection              686  $109,760, per
                                                                                             cycle.                                 inspection cycle.
Replacement.......................               4             $80  $513..................  $833.................             686  $571,438.
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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.

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-2006-26647; 
Directorate Identifier 2006-NM-194-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by January 
25, 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; 
serial numbers (S/Ns) 7003 through 7067 inclusive and S/Ns 7069 
through 7947 inclusive.

Unsafe Condition

    (d) This AD results from reports of the engine exhaust nozzle 
and fairing departing from the airplane in flight due to missing 
attachment bolts. We are issuing this AD to detect and correct 
missing or fractured attachment bolts, which could lead to the loss 
of an engine exhaust nozzle during flight and consequent structural 
damage to the airplane and hazard to people or property on the 
ground. Damage to the airplane could cause the airplane to yaw and 
result in reduced controllability 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.

Repetitive Inspections

    (f) Within 1,500 flight hours after the effective date of this AD: 
For the left and right engine exhaust nozzles, do a detailed inspection 
of the bolts that attach the exhaust nozzle to the aft engine flange to 
determine if any bolts are missing or fractured, in accordance with 
part A of the Accomplishment Instructions of Bombardier Service 
Bulletin 601R-78-021, dated June 2, 2006. If no bolt of an engine 
exhaust nozzle is missing or fractured, repeat the detailed inspection 
for that engine exhaust nozzle thereafter at intervals not to exceed 
1,500 flight hours, until the replacement specified in paragraph (g) or 
(h) of this AD is accomplished.

    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.''

Corrective Action, if Necessary

    (g) If any bolt of an engine exhaust nozzle is found missing or 
fractured during any inspection required by

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paragraph (f) of this AD, before further flight, replace the existing 
bolts that attach the exhaust nozzle to the aft engine flange with new 
improved bolts, in accordance with part B of the Accomplishment 
Instructions of Bombardier Service Bulletin 601R-78-021, dated June 2, 
2006. Accomplishing the bolt replacement for an engine exhaust nozzle 
terminates the repetitive inspections required by paragraph (f) of this 
AD for that engine exhaust nozzle only.

    Note 2: Bombardier Service Bulletin 601R-78-021, dated June 2, 
2006, refers to Short Brothers Service Bulletin CF34-NAC-78-024, 
Revision 4, dated November 10, 2005, as an additional source of 
service information for accomplishment of the replacement.

Terminating Action

    (h) Within 4,000 flight hours after the effective date of this AD: 
For the left and right engine exhaust nozzles, replace the existing 
bolts that attach the exhaust nozzle to the aft engine flange with new, 
improved bolts, in accordance with part B of the Accomplishment 
Instructions of Bombardier Service Bulletin 601R-78-021, dated June 2, 
2006. Accomplishing the replacement for the left and right engine 
exhaust nozzles terminates all of the inspections required by paragraph 
(f) of this AD.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, New York Aircraft Certification Office, 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

    (j) Canadian airworthiness directive CF-2006-19, dated July 28, 
2006, also addresses the subject of this AD.

    Issued in Renton, Washington, on December 14, 2006.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-22043 Filed 12-22-06; 8:45 am]
BILLING CODE 4910-13-P