[Federal Register Volume 67, Number 97 (Monday, May 20, 2002)]
[Proposed Rules]
[Pages 35461-35464]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-12518]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-322-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model CL-600-2B19 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 Bombardier Model CL-600-
2B19 series airplanes. This proposal would require a one-time 
inspection of the aft edge of the left and right main windshields to 
determine whether a certain placard is installed, and corrective 
actions if necessary. This action is necessary to prevent failure of 
the main windshields due to stress-related cracking, which could cause 
cabin depressurization and emergency descent, and adversely affect 
continued safe flight of the airplane. This action is intended to 
address the identified unsafe condition.

DATES: Comments must be received by June 19, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-322-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. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2001-NM-322-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 
6087, Station Centre-ville, Montreal, Quebec H3C 3G9, Canada. This 
information may be examined at the FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Engine and 
Propeller Directorate, New York Aircraft Certification Office, 10 Fifth 
Street, Third Floor, Valley Stream, New York.

FOR FURTHER INFORMATION CONTACT: Serge Napoleon, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft 
Certification Office, 10 Fifth Street,

[[Page 35462]]

Third Floor, Valley Stream, New York 11581; telephone (516) 256-7512; 
fax (516) 568-2716.

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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NM-322-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. 2001-NM-322-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    Transport Canada Civil Aviation (TCCA), which is the airworthiness 
authority for Canada, notified the FAA that an unsafe condition may 
exist on certain Bombardier Model CL-600-2B19 series airplanes. TCCA 
advises that a significant number of cracking incidents have occurred 
in the inner and middle panes of the main windshields during taxi, 
takeoff, climb, cruise, and descent of the airplane. In addition, 
frequent cracking incidents during flight have resulted in emergency 
descent, which poses an increased risk to passengers and crew members. 
Findings indicate that most of the windshield failures are due to 
excessive stress at the lower forward corner of the windshield. Failure 
of the main windshields due to stress-related cracking, if not 
corrected, could cause cabin depressurization and emergency descent, 
and adversely affect continued safe flight of the airplane.

Background Information

    Until a new design for the main windshield can be developed by the 
manufacturer and approved by the FAA, operators have requested 
procedures for modifying the existing windshields to address the 
identified unsafe condition and to improve service performance. In 
response, the manufacturer has conducted tests on windshield units 
similar to those used on in-service airplanes, and on windshield units 
fitted with reduced diameter fasteners (hi-lok pins with a reduced 
diameter shank). Findings indicate that the test units with reduced 
diameter fasteners did not fracture, unlike the windshield units fitted 
with the original diameter fasteners. Results of analysis and testing 
indicate that installation of reduced diameter fasteners in the lower 
forward corner of the windshield can reduce the stress in that area and 
increase the service life of the windshield. Findings also indicate 
that windshields with low flight cycles have a greater risk of 
windshield failure. As a result, the manufacturer recommends the 
``expeditious accomplishment'' of applicable corrective actions for 
airplanes subject to this AD and equipped with certain windshield units 
that have accumulated fewer than 2,500 total flight cycles. This 
recommendation is based on the manufacturer's statistical analysis of 
the failure rate of those windshields, and also on the tests conducted 
on the windshields.

Explanation of Relevant Service Information

    Bombardier has issued Service Bulletin 601R-56-004, dated August 
16, 2001, which describes procedures for an inspection of the left and 
right main windshields to determine the part number of the placard 
installed on the aft edge of the windshields. If a placard having the 
correct part number is found, no further action is specified. If a 
placard having the incorrect part number is found, the service bulletin 
describes procedures for modifying the main windshields. The Bombardier 
service bulletin references PPG Industries, Inc., Service Bulletin CSB-
NP-139321-002, Revision C, dated July 31, 2001, as a secondary source 
of service information for modifying the main windshields by replacing 
nine of the hi-lok pins installed in the lower forward corner of the 
windshields with hi-lok pins having a reduced diameter shank, 
installing a placard having the correct part number on the inner 
retainer near the part identification placard located along the aft 
edge of the window, and replacing any torn or deformed gasket.
    TCCA classified the Bombardier service bulletin as mandatory and 
issued Canadian airworthiness directive CF-2001-35R1, dated September 
27, 2001, in order to assure the continued airworthiness of these 
airplanes in Canada.

FAA's Conclusion

    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. The FAA has examined the findings of 
TCCA, 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.

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 require accomplishment of the actions specified in 
the Bombardier service bulletin described previously, except as 
discussed below.

Difference Between Proposed Rule and Service Bulletin/Canadian 
Airworthiness Directive

    Operators should note that the Canadian airworthiness directive and 
Bombardier Service Bulletin specify a compliance time of 12 months for 
the one-time inspection, and modification if necessary. However, this 
proposed AD would require a compliance time of 6 months after the 
effective date of this AD to accomplish the one-time general visual 
inspection, and any necessary

[[Page 35463]]

modification. In developing an appropriate compliance time for this AD, 
the FAA considered not only the manufacturer's recommendation, but the 
degree of urgency associated with addressing the subject unsafe 
condition, the average utilization of the affected fleet, and the time 
necessary to perform the inspection, and modification if necessary. In 
light of these factors, the FAA finds a compliance time of 6 months 
after the effective date of this AD to be warranted, in that it 
represents an appropriate interval of time for affected airplanes to 
continue to operate without compromising safety.

Interim Action

    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.

Cost Impact

    There are approximately 339 Model CL-600-2B19 series airplanes of 
the affected design in the worldwide fleet. The FAA estimates that 214 
airplanes of U.S. registry would be affected by this proposed AD.
    The FAA estimates that it would take approximately 1 work hour per 
airplane to accomplish the inspection, and that the average labor rate 
is $60 per work hour. Based on these figures, the cost impact of the 
proposed inspection is estimated to be $12,840, 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 proposed AD were not adopted. The cost impact 
figures discussed in AD rulemaking actions represent only the time 
necessary to perform the specific actions actually required by the AD. 
These figures typically do not include incidental costs, such as the 
time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.
    Should an operator be required to accomplish the corrective 
actions, it would take approximately 1 work hour per airplane to 
accomplish at an average labor rate of $60 per work hour. Required 
parts would be provided by the manufacturer at no cost to the operator. 
Based on these figures, the cost impact of the corrective actions is 
estimated to be $60 per airplane.

Regulatory Impact

    The regulations proposed herein 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. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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:

Bombardier, Inc. (Formerly Canadair): Docket 2001-NM-322-AD.

    Applicability: Model CL-600-2B19 series airplanes; certificated 
in any category; serial numbers 7003 and subsequent; equipped with 
main windshield units, part numbers 601R33033-1, -2, -5, -6, -9, or 
-10.

    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 failure of the main windshields due to stress-related 
cracking, which could cause cabin depressurization and emergency 
descent, and adversely affect continued safe flight of the airplane; 
accomplish the following:

Inspection and Corrective Action

    (a) For airplanes equipped with windshield units that have 
accumulated fewer than 2,500 total flight cycles as of the effective 
date of this AD: Within 6 months after the effective date of this 
AD, accomplish a one-time general visual inspection of the aft edges 
of the left and right main windshields to determine whether a 
placard having part number (P/N) CSB-NP-139321-002-1 is installed, 
per the Accomplishment Instructions of Bombardier Service Bulletin 
601R-56-004, dated August 16, 2001.
    (1) If a placard having P/N CSB-NP-139321-002-1 is installed, no 
further action is required by this AD.
    (2) If a placard having a part number other than CSB-NP-139321-
002-1 is installed, before further flight, accomplish the corrective 
actions (including modifying the main windshields by replacing nine 
of the hi-lok pins installed in the lower forward corner of the 
windshields with hi-lok pins having a reduced diameter shank, 
installing a placard having the correct part number on the inner 
retainer near the part identification placard located along the aft 
edge of the window, and replacing any torn or deformed gasket), per 
the Accomplishment Instructions of the service bulletin.

    Note 2: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made from within 
touching distance unless otherwise specified. A mirror may be 
necessary to enhance visual access to all exposed surfaces in the 
inspection area. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or droplight and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''


    Note 3: Bombardier Service Bulletin 601R-56-004, dated August 
16, 2001, references PPG Industries, Inc., Service Bulletin CSB-NP-
139321-002, Revision C, dated July 31, 2001, as an additional source 
of service information for accomplishment of the modification of the 
left and right main windshields.

Alternative Methods of Compliance

    (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, New York Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, New York ACO.


[[Page 35464]]


    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York ACO.

Special Flight Permit

    (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.

    Note 5: The subject of this AD is addressed in Canadian 
airworthiness directive CF-2001-35R1, dated September 27, 2001.



    Issued in Renton, Washington, on May 13, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-12518 Filed 5-17-02; 8:45 am]
BILLING CODE 4910-13-P