[Federal Register Volume 68, Number 203 (Tuesday, October 21, 2003)]
[Proposed Rules]
[Pages 60047-60049]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-26469]


 ========================================================================
 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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 

  Federal Register / Vol. 68, No. 203 / Tuesday, October 21, 2003 / 
Proposed Rules  

[[Page 60047]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-267-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model CL-600-1A11 (CL-600), 
CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-
604) Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to revise an existing airworthiness 
directive (AD), applicable to certain Bombardier Model CL-600-1A11 (CL-
600), CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A, CL-601-3R, and 
CL-604) series airplanes, that currently requires repetitive 
inspections to find cracks of a certain bulkhead web of the fuselage at 
certain locations, and repair if necessary. The actions specified by 
that AD are intended to prevent cracking in the pressure bulkhead at 
frame station (FS) 409.00, which could result in uncontrolled 
depressurization of the airplane and/or reduced structural integrity of 
the fuselage. This action would provide an optional terminating 
modification for certain airplanes. This action is intended to address 
the identified unsafe condition.

DATES: Comments must be received by November 20, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-267-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. 2001-NM-267-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 Centreville, 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, 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, Third Floor, Valley Stream, New 
York; 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:
    [sbull] 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.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] 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-267-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-267-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On November 10, 1997, the FAA issued AD 97-24-02, amendment 39-
10209 (62 FR 61436, November 18, 1997), applicable to certain 
Bombardier Model CL-600-1A11, -2A12, and -2B16 series airplanes, to 
require repetitive inspections to find cracks of a certain bulkhead web 
of the fuselage at certain locations, and repair if necessary. That 
action was prompted by mandatory continuing airworthiness information 
by a foreign civil airworthiness authority. The requirements of that AD 
are intended to detect and correct cracking in the pressure bulkhead at 
frame station (FS) 409.00, which could result in uncontrolled 
depressurization of the airplane and/or reduced structural integrity of 
the fuselage.

Actions Since Issuance of Previous Rule

    In the preamble to AD 97-24-02, we specified that we considered the 
requirements ``interim action'' and that the manufacturer was 
developing a modification to address the unsafe condition. That AD 
explained that we may consider further rulemaking if a modification is 
developed, approved, and available. The manufacturer now has developed 
such a modification, and we have determined that further rulemaking is 
indeed necessary; this

[[Page 60048]]

proposed AD follows from that determination.

Explanation of Relevant Service Information

    Bombardier has issued Service Bulletin 600-0680 (for Model CL-600-
1A11 (CL-600) series airplanes), Service Bulletin 601-0503 (for Model 
CL-600-2A12 (CL-601) and CL-600-2B16 (CL-601-3A/-3R) series airplanes), 
and Service Bulletin 604-53-006 (for Model CL-600-2B16 (CL-604) series 
airplanes), all dated November 30, 1999. The service bulletins describe 
procedures for modification of the pressure bulkhead at FS 409.00. The 
modification includes an eddy current inspection for cracking of the 
bulkhead; reinforcement of the pressure bulkhead frame; and a pressure 
test, leak test, operational test, and functional test of all systems.
    Transport Canada Civil Aviation (TCCA), which is the airworthiness 
authority for Canada, classified these service bulletins as mandatory 
and issued Canadian airworthiness directive CF-1997-16R2, dated May 31, 
2001, in order to ensure the continued airworthiness of these airplanes 
in Canada.

FAA's Conclusions

    These airplane models are manufactured in Canada and are 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, TCCA has kept the FAA 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 Rule

    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 revise AD 97-24-02 to 
continue to require repetitive inspections to find cracks of a certain 
bulkhead web of the fuselage at certain locations, and repair if 
necessary. For certain airplanes, this proposed AD also would provide 
for an optional terminating modification for the repetitive 
inspections. Consistent with the findings of TCCA, the proposed AD 
would allow repetitive inspections to continue in lieu of the 
terminating action. In making this determination, we considered that 
long-term continued operational safety in this case will be adequately 
ensured by repetitive inspections to detect cracking before it 
represents a hazard to the airplane. The actions would be required to 
be accomplished in accordance with the service bulletins described 
previously, except as discussed below.

Differences Between Proposed Rule and Service Bulletins/Canadian 
Airworthiness Directive

    The Canadian airworthiness directive specifies reporting crack 
findings to the manufacturer; however, this proposed AD would not 
require such action.
    The Accomplishment Instructions of the referenced service bulletins 
describe procedures for completing an Incorporation Notice. However, 
this proposed AD would not require such action.
    In addition, although the service bulletins specify that operators 
may contact the manufacturer for disposition of certain repair 
conditions, this proposal would require operators to repair those 
conditions per a method approved by either 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 either the FAA or TCCA would be acceptable for 
compliance with this proposed AD.

Explanation of Change Made To Existing Requirements

    We have changed all references to a ``detailed visual inspection'' 
in the existing AD to a ``detailed inspection'' in this action.

Cost Impact

    There are approximately 237 airplanes of U.S. registry that would 
be affected by this proposed AD.
    The inspections that are required by AD 97-24-02 take approximately 
2 work hours per airplane to accomplish, at an average labor rate of 
$65 per work hour. Based on these figures, the cost impact of the 
currently required actions is estimated to be $130 per airplane, per 
inspection cycle.
    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 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.
    The optional terminating modification, if done, would take between 
125 and 300 work hours per airplane, depending on the airplane 
configuration, at an average labor rate of $65 per work hour. Required 
parts would be provided by the manufacturer at no cost to operators. 
Based on these figures, we estimate the cost of the modification to be 
between $8,125 and $19,500 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.

[[Page 60049]]

Sec.  39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-10209 (62 FR 
61436, November 18, 1997), and by adding a new airworthiness directive 
(AD), to read as follows:

Bombardier, Inc. (Formerly Canadair): Docket 2001-NM-267-AD. Revises 
AD 97-24-02, Amendment 39-10209.

    Applicability: Model CL-600-1A11 (CL-600) series airplanes, 
serial numbers 1004 through 1085 inclusive; Model CL-600-2A12 (CL-
601) series airplanes, serial numbers 3001 through 3066 inclusive; 
Model CL-600-2B16 (CL-601-3A/-3R) series airplanes, serial numbers 
5001 through 5194 inclusive; and Model CL-600-2B16 (CL-604) series 
airplanes, serial numbers 5301 through 5352 inclusive; certificated 
in any category.
    Compliance: Required as indicated, unless accomplished 
previously. To prevent cracking in the pressure bulkhead at frame 
station (FS) 409.00, which could result in uncontrolled 
depressurization of the airplane and/or reduced structural integrity 
of the fuselage, accomplish the following:

Restatement of Requirements of AD 97-24-02: Detailed Inspections/Repair

    (a) For Model CL-600-1A11 (CL-600) airplanes: Prior to the 
accumulation of 1,900 total landings, or within 100 landings after 
December 3, 1997 (the effective date of AD 97-24-02, amendment 39-
10209), whichever occurs later, perform a detailed inspection to 
detect cracks at FS 409.00 of the bulkhead web (part number (P/N) 
600-32014-71/-95/-105), in accordance with Canadair Challenger 
Service Bulletin 600-0679, dated September 12, 1997.

    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.''

    (1) If no crack is detected, repeat the detailed inspection 
thereafter at intervals not to exceed 600 landings.
    (2) If any crack is detected and if all three of the conditions 
specified in paragraphs (a)(2)(i), (a)(2)(ii), and (a)(2)(iii) of 
this AD are met, within 600 landings or 12 months after the crack is 
detected, whichever occurs first, repair the crack in accordance 
with a method approved by the Manager, New York Aircraft 
Certification Office (ACO), FAA. Until the repair is accomplished, 
repeat the detailed inspection at intervals not to exceed 100 
landings.
    (i) No more than one crack exists at each corner radius, as 
specified in the service bulletin; and
    (ii) No crack extends under the angles having P/N 600-32014-13 
and P/N 600-32014-15 on the aft side of the bulkhead web; and
    (iii) No crack exists in angles having P/N 600-32014-13 and P/N 
600-32014-15 on the aft side of the bulkhead web.
    (3) If any crack other than that identified in paragraph (a)(2) 
of this AD is detected, prior to further flight, repair it in 
accordance with a method approved by the Manager, New York ACO.
    (b) For Model CL-600-2A12 (CL-601), CL-600-2B16 (CL-601-3A/-3R), 
and CL-600-2B16 (CL-604) series airplanes: Prior to the accumulation 
of 1,100 total landings, or within 100 landings after December 3, 
1997, whichever occurs later, perform a detailed inspection to 
detect cracks at FS 409.00 of the bulkhead web (P/N 600-32014-105/-
137), in accordance with Canadair Challenger Service Bulletin 601-
0501, dated September 12, 1997 (for Model CL-600-2A12 (CL-601) and 
CL-600-2B16 (CL-601-3A/-3R) series airplanes); or Canadair 
Challenger Service Bulletin 604-53-007, dated September 30, 1997 
(for Model CL-600-2B16 (CL-604) series airplanes); as applicable.
    (1) If no crack is detected, repeat the detailed inspection 
thereafter at intervals not to exceed 600 landings.
    (2) If any crack is detected and if all three of the conditions 
specified in paragraphs (b)(2)(i), (b)(2)(ii), and (b)(2)(iii) of 
this AD are met, within 600 landings or 12 months after the crack is 
detected, whichever occurs first, repair the crack in accordance 
with a method approved by the Manager, New York ACO. Until the 
repair is accomplished, repeat the detailed inspection at intervals 
not to exceed 100 landings.
    (i) No more than one crack exists at each corner radius, as 
specified in the service bulletin; and
    (ii) No crack extends under the angles having P/N 600-32014-113 
and P/N 600-32014-115 on the aft side of the bulkhead web; and
    (iii) No crack exists in angles having P/N 600-32014-113 and P/N 
600-32014-115 on the aft side of the bulkhead web.
    (3) If any crack other than that identified in paragraph (b)(2) 
of this AD is detected, prior to further flight, repair it in 
accordance with a method approved by the Manager, New York ACO.

New Requirements of This AD: Optional Terminating Modification

    (c) For airplanes on which no crack has been found during 
accomplishment of any inspection required by AD 97-24-02; or on 
which the pressure bulkhead was not previously repaired: 
Modification of the pressure bulkhead at FS 409.00 (including 
inspection, installation of reinforcing material, and tests) by 
accomplishing all the actions specified in paragraphs 2.A. through 
2.D. of the Accomplishment Instructions of Bombardier Service 
Bulletin 601-0503 (for Model CL-601 and CL-601-3A/-3R series 
airplanes), Service Bulletin 600-0680 (for Model CL-600 series 
airplanes), or Service Bulletin 604-53-006 (for Model CL-604 series 
airplanes); all dated November 30, 1999, per the applicable service 
bulletin, terminates the repetitive inspections required by this AD.

Repair

    (d) If any crack is found during any inspection specified in 
paragraph (c) of this AD: Before further flight, repair in 
accordance with a method approved by the Manager, New York ACO; or 
Transport Canada Civil Aviation or its delegated agent.

Alternative Methods of Compliance

    (e) In accordance with 14 CFR 39.19, the Manager, New York ACO, 
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-1997-16R2, dated May 31, 2001.


    Issued in Renton, Washington, on October 10, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-26469 Filed 10-20-03; 8:45 am]
BILLING CODE 4910-13-P