[Federal Register Volume 69, Number 106 (Wednesday, June 2, 2004)]
[Proposed Rules]
[Pages 31047-31049]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-12445]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-158-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model CL-600-2B19 (Regional 
Jet Series 100 & 440) 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 all Bombardier Model CL-600-2B19 
(Regional Jet Series 100 & 440) airplanes. This proposal would require 
repetitive inspections of the check valves and air supply ducts of the 
rear bulkhead for damage, and related corrective actions. This proposal 
also would require eventual rework or replacement of the air supply 
ducts, which would terminate the repetitive inspections for the air 
supply ducts only. This action is necessary to prevent disconnection of 
an air supply duct, which, if combined with failure of a bulkhead check 
valve, could result in rapid depressurization of the airplane. This 
action is intended to address the identified unsafe condition.

DATES: Comments must be received by July 2, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2003-NM-158-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. 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. 2003-NM-158-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 or 2000 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, New York Aircraft Certification 
Office, 1600 Stewart Avenue, suite 410, Westbury, New York; or at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Dan Parillo, Aerospace Engineer, 
Systems and Flight Test Branch, ANE-172, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Westbury, suite 410, New 
York 11590; telephone (516) 228-7305; fax (516) 794-5531.

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 2003-NM-158-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. 2003-NM-158-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 all Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 
440) airplanes. TCCA advises that the flanges on the air supply ducts 
of the rear bulkhead were bonded to the duct using a manufacturing 
procedure that did not meet design specifications. Investigation 
revealed that such bonding could lose 80 percent of its shear strength 
at elevated temperatures. If the bonding loses shear strength, it could 
result in premature cracking and consequent

[[Page 31048]]

failure (detachment of the flappers) of the bulkhead check valve. 
Disconnection of an air supply duct, if combined with failure of a 
bulkhead check valve, could result in rapid depressurization of the 
airplane.

Explanation of Relevant Service Information

    Bombardier has issued Alert Service Bulletin A601R-21-053, Revision 
``A'', dated January 28, 2003, which describes procedures for 
repetitive inspections of the air supply ducts of the rear bulkhead for 
damage. Bombardier has also issued Alert Service Bulletin A601R-21-054, 
dated November 8, 2001, which describes procedures for repetitive 
inspections of the check valves of the rear bulkhead for damage. Both 
service bulletins describe procedures for related corrective actions if 
any damage is found. Service Bulletin A601R-21-054 recommends that 
Service Bulletin A601R-21-053, Revision ``A'', be done at the same 
time.
    Service Bulletin A601R-21-053, Revision ``A'', describes procedures 
for the following: A visual inspection of the left- and right-hand air 
supply ducts for damage (tearing, delamination, or cracking). If any 
damage is found, the corrective action involves replacement of the 
affected duct with a new duct before further flight, which eliminates 
the need for the repetitive inspections for that duct only. If no 
damage is found, the inspection is repeated. The service bulletin also 
describes procedures for eventual rework or replacement of the air 
supply ducts, which eliminates the need for the repetitive inspections 
of the air supply ducts.
    Service Bulletin A601R-21-054 describes procedures for the 
following: A visual inspection of the bulkhead check valves (including 
the guide clamps) for damage (cracking or breakage), and a leak test of 
the air conditioning system. If any damage is found, the corrective 
action involves replacement of the affected bulkhead check valve with a 
new valve before further flight. If no damage is found, the inspection 
is repeated.
    Accomplishment of the actions specified in the service information 
is intended to adequately address the identified unsafe condition. TCCA 
classified this service information as mandatory and issued Canadian 
airworthiness directive CF-2003-05, dated February 4, 2003, to ensure 
the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

    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 us informed of the 
situation described above. We have 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 AD

    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 accomplishment of 
the actions specified in the service information described previously, 
except as discussed below.

Differences Among Canadian Airworthiness Directive, Service 
Information, and This Proposed AD

    The applicability in the Canadian airworthiness directive specifies 
Bombardier Model CL-600-2B19 airplanes, serial numbers 7003 through 
7477; however, the proposed AD would be applicable to all Bombardier 
Model CL-600-2B19 airplanes. TCCA has informed us that the Canadian 
airworthiness directive is in error, and should have specified all 
Bombardier Model CL-600-2B19 airplanes.
    The Canadian airworthiness directive requires amending the 
Transport Canada approved maintenance schedule within 30 days after the 
effective date of the Canadian airworthiness directive, by 
incorporating Inspection Task No. 21-51-21-07, and incorporating the 
task interval for the bulkhead check valves, as specified in Part 1, 
Section 2, of Revision 7 of the Maintenance Review Board Report, dated 
April 11, 2001. However, this proposed AD does not contain such a 
requirement, but would mandate the equivalent maintenance tasks 
specified in Service Bulletin A601R-21-054, in lieu of amending the 
maintenance schedule. We have determined that these tasks address the 
unsafe condition in the same manner as would amending the maintenance 
schedule.
    The Canadian airworthiness directive does not specifically cite a 
repetitive inspection interval for the check valves; Inspection Task 
No. 21-51-21-07, cited in the Canadian airworthiness directive, does 
require repetitive inspections. This proposed AD would require 
repeating the inspections of the check valves at intervals not to 
exceed 4,000 flight hours, which is in line with the Canadian 
requirements. The inspections will continue until a terminating action 
is developed, approved, and available.
    The Canadian airworthiness directive and Service Bulletin A601R-21-
054 recommend sending all damaged check valves to the manufacturer for 
analysis; however, this AD does not include that requirement.
    The service bulletins referenced in this proposed AD specify to 
submit certain information to the manufacturer, but this proposed AD 
does not include such a requirement.

Clarification of Type of Inspection

    The Canadian airworthiness directive and the referenced service 
bulletins specify that operators do a visual inspection of the check 
valves and air supply ducts of the rear bulkhead. We have determined 
that the inspection procedures should be described as a ``detailed 
inspection.'' Note 1 has been included in this proposed AD to define 
this type of inspection.

Interim Action

    This proposed AD is considered to be interim action. Analysis of 
the check valves is being done by the manufacturer to obtain better 
insight into the nature, cause, and extent of the damage, and 
eventually to develop final action to address the unsafe condition. 
Once final action has been identified, we may consider further 
rulemaking.

Cost Impact

    We estimate that 280 airplanes of U.S. registry would be affected 
by this proposed AD.
    It would take about 2 work hours per airplane to accomplish the 
proposed inspection of the check valves, at an average labor rate of 
$65 per work hour. Based on these figures, the cost impact of the 
proposed inspection on U.S. operators is estimated to be $36,400, or 
$130 per airplane, per inspection cycle.
    It would take about 4 work hours per airplane to accomplish the 
proposed inspection of the air supply duct, at an average labor rate of 
$65 per work hour. Based on these figures, the cost impact of the 
proposed inspection on U.S. operators is estimated to be $72,800, or 
$260 per airplane, per inspection cycle.
    It would take about 4 work hours per airplane to accomplish the 
proposed replacement of the check valves, at an average labor rate of 
$65 per work hour. Required parts would be free of charge.

[[Page 31049]]

Based on these figures, the cost impact of the proposed replacement on 
U.S. operators is estimated to be $72,800, or $260 per airplane.
    It would take about 3 work hours per airplane to accomplish the 
proposed rework of the air supply ducts, at an average labor rate of 
$65 per work hour. Required parts would be free of charge. Based on 
these figures, the cost impact of the proposed rework on U.S. operators 
is estimated to be $54,600, or $195 per airplane.
    It would take about 2 work hours per airplane to accomplish the 
proposed replacement of the air supply ducts, at an average labor rate 
of $65 per work hour. Required parts would be free of charge. Based on 
these figures, the cost impact of the proposed replacement on U.S. 
operators is estimated to be $36,400, or $130 per airplane.
    The cost impact figures discussed above are 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 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.

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 2003-NM-158-AD.

    Applicability: All Model CL-600-2B19 (Regional Jet Series 100 & 
440) airplanes, certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent disconnection of an air supply duct, which, if 
combined with failure of a bulkhead check valve, could result in 
rapid depressurization of the airplane, accomplish the following:

Service Information References

    (a) Paragraphs (a)(1), (a)(2), (a)(3), and (a)(4) of this AD 
pertain to the service information referenced in this AD.
    (1) The term service bulletin, as used in this AD, means the 
Accomplishment Instructions of Bombardier Alert Service Bulletin 
A601R-21-053, Revision ``A'', dated January 28, 2003; or Bombardier 
Alert Service Bulletin A601R-21-054, dated November 8, 2001; as 
applicable.
    (2) Although the service bulletins referenced in this AD specify 
to submit certain information to the manufacturer, this AD does not 
include such a requirement.
    (3) Bombardier Alert Service Bulletin A601R-21-054, dated 
November 8, 2001, recommends sending all damaged check valves to the 
manufacturer for analysis; however, this AD does not include that 
requirement.
    (4) Accomplishment of the actions specified in Bombardier Alert 
Service Bulletin A601R-21-053, dated November 8, 2001, before the 
effective date of this AD is considered acceptable for compliance 
with the applicable actions specified in this AD.

Repetitive Inspections/Related Corrective Actions

    (b) Within 500 flight hours after the effective date of this AD: 
Do the detailed inspections and related corrective actions required 
by paragraphs (b)(1) and (b)(2) of this AD, per the applicable 
service bulletin.
    (1) Inspect the left- and right-hand bulkhead check valves for 
damage (cracking, breakage). If any damage is found, before further 
flight, replace the damaged valve. Repeat the inspection at 
intervals not to exceed 4,000 flight hours.
    (2) Inspect the left- and right-hand air supply ducts of the 
rear bulkhead for damage (tearing, delamination, or cracking). If 
any damage is found, before further flight, either rework or replace 
the damaged air supply duct, which ends the inspections for that air 
supply duct only. If no damage is found, repeat the inspection 
thereafter at intervals not to exceed 500 flight hours until 
accomplishment of paragraph (c) of this AD.

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

Terminating Action for Repetitive Inspections of Air Supply Ducts

    (c) Except as required by paragraph (b)(2) of this AD: Within 
5,000 flight hours after the effective date of this AD, either 
rework or replace the left- and right-hand air ducts, as applicable, 
per the applicable service bulletin. Accomplishment of this 
paragraph ends the repetitive inspections required by paragraph 
(b)(2) of this AD.

Alternative Methods of Compliance

    (d) In accordance with 14 CFR 39.19, the Manager, New York 
Aircraft Certification Office, FAA, is authorized to approve 
alternative methods of compliance for this AD.

    Note 2: The subject of this AD is addressed in Canadian 
airworthiness directive CF-2003-05, dated February 4, 2003.


    Issued in Renton, Washington, on May 20, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-12445 Filed 6-1-04; 8:45 am]
BILLING CODE 4910-13-P