[Federal Register Volume 61, Number 131 (Monday, July 8, 1996)]
[Proposed Rules]
[Pages 35691-35693]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-17218]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 95-NM-247-AD]
RIN 2120-AA64
Airworthiness Directives; Bombardier Model CL-600-2B16 (CL-601-3A
and -3R) and CL-600-2B19 (Regional Jet Series 100) 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-
2B16 and CL-600-2B19 series airplanes. This proposal would require a
one-time inspection of the spring bungee assembly of the nose landing
gear (NLG) to ensure proper torque of the collar and correct clearance
between the collar and the body of the bungee, and replacement of the
spring bungee assembly with a serviceable unit, if necessary. This
proposal is prompted by reports of failure of the NLG to extend when
the landing gear selector was placed in the ``DOWN'' position, and
failure of the NLG doors to open when the NLG door switch was set in
the ``SAFETY/DOOR OPEN'' position; these conditions may have been
caused by a reduced stroke of the spring bungee. The actions specified
by the proposed AD are intended to prevent improper operation of the
NLG door and consequent inability to extend the NLG due to a reduced
stroke of the spring bungee.
DATES: Comments must be received by August 16, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-247-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.
The service information referenced in the proposed rule may be
obtained from Bombardier, Inc., Canadair, Aerospace Group, P.O. Box
6087, Station Centre-ville, 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: Danko Kramar, Aerospace Engineer,
Systems and Flight Test Branch, ANE-172, FAA, New York Aircraft
Certification Office, Engine and Propeller Directorate, 10 Fifth
Street, Third Floor, Valley Stream, New York; telephone (516) 256-7509;
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 notice may be changed in
light of the comments received.
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 notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 95-NM-247-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-103, Attention: Rules
Docket No. 95-NM-247-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
Transport Canada Aviation, which is the airworthiness authority for
Canada, recently notified the FAA that an unsafe condition may exist on
certain Bombardier Model CL-600-2B16 (CL-601-3A and -3R), and CL-600-
2B19 (Regional Jet Series 100) series airplanes. Transport Canada
Aviation advises that it received reports indicating that, during
flight of a Model CL-600-2B19 series airplane, the nose landing gear
(NLG) did not extend when the landing gear selector was placed in the
``DOWN'' position. The NLG did extend following cycling of the selector
valve. Transport Canada Aviation also advises that it received a report
indicating that, during a pre-flight check of a Model CL-600-2B16
series airplane, the NLG doors did not open when the NLG door switch
was set in the ``SAFETY/DOOR OPEN'' position. The cause of these
occurrences has been attributed to a defective spring bungee assembly
of the NLG door mechanism. Investigation revealed that the spring
[[Page 35692]]
bungee may have a reduced stroke due to incorrect clearance between the
collar and the body of the spring bungee. This incorrect clearance was
the result of incorrect assembly during manufacture. This condition, if
not corrected, could result in improper operation of the NLG door,
which could result in inability to extend the NLG.
Explanation of Relevant Service Information
The manufacturer has issued Canadair Regional Jet Alert Service
Bulletin A601R-32-037, Revision ``A,'' dated December 2, 1994 (for
Model CL-600-2B19 series airplanes), and Canadair Challenger Service
Bulletin 601-0454, dated May 15, 1995, as amended by Service Bulletin
Information Sheet 601-0454, dated July 14, 1995 (for Model CL-600-2B16
series airplanes). These service bulletins describe procedures for a
one-time inspection of the spring bungee assembly of the NLG to ensure
proper torque of the collar and correct clearance between the collar
and the body of the bungee, and replacement of the spring bungee
assembly with a serviceable (new or reworked) unit, if necessary.
Transport Canada Aviation classified these service bulletins as
mandatory and issued Canadian airworthiness directive CF-95-10, dated
June 27, 1995, in order to assure 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
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and
the applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, Transport Canada Aviation has kept
the FAA informed of the situation described above. The FAA has examined
the findings of Transport Canada Aviation, 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, the
proposed AD would require a one-time inspection of the spring bungee
assembly of the NLG to ensure proper torque of the collar and correct
clearance between the collar and the body of the bungee, and
replacement of the spring bungee assembly with a serviceable (new or
reworked) unit, if necessary. The actions would be required to be
accomplished in accordance with the service bulletins described
previously.
Explanation of Differences between Service Bulletins and the
Proposed Rule
Operators should note that the compliance time specified in this
proposed AD (within 90 days after the effective date of the AD) differs
from the times recommended in the referenced service bulletins. [The
compliance time recommended in Canadair Challenger Service Bulletin
601-0454 for Model CL-600-2B16 series airplanes is ``at the next 300-
hour check.'' Canadair Regional Jet Alert Service Bulletin A601R-32-037
(for Model CL-600-2B19 series airplanes) recommends a compliance time
of no later than the next ``A'' check or within the next three months
after receipt of the alert service bulletin.] The FAA finds that the
compliance time should not differ for each airplane model, since the
spring bungee installed on both models has the same part number. In
developing an appropriate compliance time for this AD, the FAA also
considered not only the degree of urgency associated with addressing
the subject unsafe condition, but availability of replacement parts and
the maximum interval of time allowable for all affected airplanes to
continue to operate without compromising safety. The FAA finds 90 days
to be an appropriate compliance time for accomplishing these actions.
Cost Impact
The FAA estimates that 101 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 4 work
hours per airplane to accomplish the proposed actions, and that the
average labor rate is $60 per work hour. Based on these figures, the
cost impact of the proposed AD on U.S. operators is estimated to be
$24,240, or $240 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 AD were not adopted.
Regulatory Impact
The regulations proposed herein would not have substantial direct
effects 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, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
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 95-NM-247-AD.
Applicability: Model CL-600-2B16 (CL-601-3A and -3R), serial
numbers 5100 through 5166 inclusive; and Model CL-600-2B19 (Regional
Jet Series 100) series airplanes, serial numbers 7003 through 7048
inclusive; certificated in any category.
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 (d) 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
[[Page 35693]]
been eliminated, the request should include specific proposed
actions to address it.
Compliance: Required as indicated, unless accomplished
previously.
To prevent improper operation of the nose landing gear (NLG)
door and consequent inability to extend the NLG due to a reduced
stroke of the spring bungee, accomplish the following:
(a) Within 90 days after the effective date of this AD: Perform
a one-time inspection of the spring bungee assembly of the NLG to
ensure proper torque of the collar and correct clearance between the
collar and the body of the bungee; in accordance with Canadair
Regional Jet Alert Service Bulletin A601R-32-037, Revision `A,'
dated December 2, 1994 (for Model CL-600-2B19 series airplanes); or
Canadair Challenger Service Bulletin 601-0454, dated May 15, 1995,
as amended by Service Bulletin Information Sheet 601-0454, dated
July 14, 1995 (for Model CL-600-2B16 series airplanes); as
applicable.
(b) If improper torque of the collar is found, or if incorrect
clearance between the collar and the body of the bungee is found:
Prior to further flight, replace the spring bungee assembly with a
serviceable (new or reworked) unit that has been inspected in
accordance with Canadair Regional Jet Alert Service Bulletin A601R-
32-037, Revision ``A'', dated December 2, 1994 (for Model CL-600-
2B19 series airplanes); or Canadair Challenger Service Bulletin 601-
0454, dated May 15, 1995, as amended by Service Bulletin Information
Sheet 601-0454, dated July 14, 1995 (for Model CL-600-2B16 series
airplanes); as applicable. Accomplish the replacement in accordance
with the applicable service bulletin.
(c) As of the effective date of this AD, no person shall install
a spring bungee assembly having part number 600-86115-1 (for Model
CL-600-2B16 series airplanes) or 600-86115-5/70 (for Model CL-600-
2B19 series airplanes) on any airplane unless that assembly has been
inspected and reworked, as necessary, in accordance with paragraph
(a) of this AD.
(d) 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, Engine and Propeller Directorate. 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.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the New York ACO.
(e) 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.
Issued in Renton, Washington, on July 1, 1996.
S. R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-17218 Filed 7-5-96; 8:45 am]
BILLING CODE 4910-13-P
