[Federal Register Volume 60, Number 166 (Monday, August 28, 1995)]
[Rules and Regulations]
[Pages 44419-44421]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-20632]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-139-AD; Amendment 39-9344; AD 95-17-14]


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Bombardier Model CL-600-1A11, CL-600-2A12, and 
CL-600-2B16 series airplanes. This action requires functional testing 
of the brake of the horizontal stabilizer trim actuator (HSTA); and 
exercising the pitch trim system, revising the FAA-approved Airplane 
Flight Manual (AFM), operational testing of the HSTA, and replacing the 
HSTA or horizontal stabilizer trim control unit, if necessary. This 
amendment is prompted by reports of overspeed annunciation of the pitch 
trim due to slippage of the no-back device on the HSTA. The actions 
specified in this AD are intended to prevent uncommanded movement of 
the HSTA due to failure of the no-back device on the HSTA to operate 
properly; this condition could adversely affect the controllability of 
the airplane.

DATES: Effective September 12, 1995.-
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 12, 1995.-
    Comments for inclusion in the Rules Docket must be received on or 
before October 27, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-139-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. -
    The service information referenced in this AD 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, New York Aircraft Certification 
Office, Engine and Propeller Directorate, 10 Fifth Street, Third Floor, 
Valley Stream, New York; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Peter Cuneo, Aerospace Engineer, 
Systems and Equipment Branch, ANE-173, FAA, New York Aircraft 
Certification Office, Engine and Propeller Directorate, 10 Fifth 
Street, Third Floor, Valley Stream, New York 11581; telephone (516) 
256-7506; fax (516) 568-2716.

SUPPLEMENTARY INFORMATION: 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-600-1A11 (CL-
600), CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A and -3R) series 
airplanes. Transport Canada Aviation advises that it has received 
reports of overspeed annunciation of the pitch trim. Each time such 
annunciation occurred, the horizontal stabilizer trim actuator (HSTA) 
mechanical brake prevented uncommanded movement of the HSTA, i.e., HSTA 
runaway. Investigation has revealed that the reported overspeed 
annunciation of the pitch trim may be attributed to slippage of the no-
back device on the HSTA. Further investigation revealed that the no-
back device on the HSTA failed to operate properly at low temperatures, 
but operated properly at ambient temperatures above zero degrees 
centigrade. This condition, if not corrected, could result in 
uncommanded movement of the HSTA, which could adversely affect the 
controllability of the airplane. -
    Bombardier has issued Alert Service Bulletins A600-0645 (for Model 
CL-600-1A11 series airplanes), and A601-0443 (for Model CL-600-2A12 and 
CL-600-2B16 series airplanes), both dated January 11, 1995, which 
describe procedures for an operational test of the HSTA brake, and 
replacement of the HSTA or horizontal stabilizer trim control unit 
(HSTCU) with a serviceable unit. Transport Canada Aviation approved 
these service bulletins and issued Canadian airworthiness directive CF-
95-02, dated February 28, 1995, in order to assure the continued 
airworthiness of these airplanes in Canada. -
    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, Transport Canada Aviation has kept 
the FAA informed of the situation described above. The FAA has examined 
the findings of Transport Canada Aviation, 

[[Page 44420]]
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. -
    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, this AD is being issued to prevent uncommanded 
movement of the HSTA. This AD requires repetitive functional testing of 
the HSTA brake for all airplanes. If certain conditions are found to 
exist during the functional tests, this AD also requires exercising of 
the pitch trim system, revising the Limitations Section of the FAA-
approved Airplane Flight Manual (AFM), operational testing of the HSTA, 
and replacing the HSTA or HSTCU with a serviceable unit. Accomplishment 
of the replacement terminates the requirement to exercise the pitch 
trim system and revise the AFM.
    -Operational testing of the HSTA and replacement of the HSTA or 
HSTCU are required to be accomplished in accordance with the applicable 
alert service bulletin described previously. -
    As a result of recent communications with the Air Transport 
Association (ATA) of America, the FAA has learned that, in general, 
some operators may misunderstand the legal effect of AD's on airplanes 
that are identified in the applicability provision of the AD, but that 
have been altered or repaired in the area addressed by the AD. The FAA 
points out that all airplanes identified in the applicability provision 
of an AD are legally subject to the AD. If an airplane has been altered 
or repaired in the affected area in such a way as to affect compliance 
with the AD, the owner or operator is required to obtain FAA approval 
for an alternative method of compliance with the AD, in accordance with 
the paragraph of each AD that provides for such approvals. A note has 
been included in this rule to clarify this long-standing requirement. -
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited -

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed. -
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket. -
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 95-NM-139-AD.'' The postcard will be date stamped and 
returned to the commenter. -
    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment. -
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39 -

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment -

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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), 40101, 40113, 44701.


Sec. 39.13  [Amended] -

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

95-17-14  Bombardier, Inc. (Formerly Canadair): Amendment 39-9344. 
Docket 95-NM-139-AD. -
    Applicability: Model CL-600-1A11 (CL-600) series airplanes 
having serial numbers 1004 through 1085 inclusive; Model CL-600-2A12 
(CL-601) series airplanes having serial numbers 3001 through 3066 
inclusive; and Model CL-600-2B16 (CL-601-3A and -3R) series 
airplanes having serial numbers 5001 through 5137 inclusive, and 
5139 through 5299 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 use the authority 
provided in paragraph (e) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD. -

    Compliance: Required as indicated, unless accomplished 
previously. -
    To prevent uncommanded movement of the horizontal stabilizer 
trim actuator (HSTA), accomplish the following: -
    (a) Within 20 hours time-in-service after the effective date of 
this AD, perform the following ``Functional Test Procedures of the 
HSTA Brake'': -
    (1) Press the CHAN 1 INOP/CHAN 2 INOP switch/light and then the 
OVSP/CHNG CHAN switch/light on the center pedestal control panel. -

[[Page 44421]]

    (2) Set and hold the pitch trim switch on the pilot's control 
wheel until the stabilizer is in full NOSE UP position. -
    (3) Set and hold the pitch trim switch on the pilot's control 
wheel to NOSE DOWN position and, while the stabilizer is moving, 
press the PITCH TRIM DISC switch on the pilot's control wheel when 
the needle on the stabilizer trim position indicator reaches the 
first marking of the take-off configuration green band. Verify that 
both CHAN INOP lights are on. -
    (4) Verify that the stabilizer over-travel is less than one 
degree, as read on the stabilizer trim position indicator on the 
center instrument panel.

    -Note 2: One increment on the stabilizer trim position indicator 
is equal to one degree of stabilizer travel.

    (i) If the stabilizer over-travel is less than or equal to one 
degree, the pitch trim brake performance meets the ground 
performance requirements and is considered serviceable.
    -(ii) If the stabilizer over-travel is more than one degree, 
dispatch is prohibited. Correction is required prior to further 
flight, in accordance with Bombardier Alert Service Bulletin A600-
0645, dated January 11, 1995 (for Model CL-600-1A11 series 
airplanes), or A601-0443, dated January 11, 1995 (for Model CL-600-
2A12 and CL-600-2B16 series airplanes), as applicable.
    -(b) For airplanes on which the stabilizer over-travel is shown 
to be equal to or less than 1 degree during the functional test 
required by paragraph (a) of this AD, and no overspeed annunciation 
has been reported previously, repeat the functional test thereafter 
at intervals not to exceed 100 hours time-in-service.
    -(c) For airplanes on which the stabilizer over-travel is shown 
to be equal to or less than 1 degree during the functional test 
required by paragraph (a) of this AD, and overspeed annunciation has 
been reported previously, accomplish paragraphs (c)(1), (c)(2), 
(c)(3), and (c)(4) of this AD.
    -(1) Prior to each flight, exercise the pitch trim system by 
accomplishing the following: ``Command full NOSE DOWN, then full 
NOSE UP and re-position.''
    -(2) Prior to further flight following accomplishment of the 
functional test required by paragraph (a) of this AD, revise the 
Limitations Section of the FAA-approved Airplane Flight Manual (AFM) 
to include the following information. This may be accomplished by 
inserting a copy of this AD in the AFM.

    ``1. Do not engage autopilot at an altitude below 1,000 feet 
AGL.
    ``2. Monitor 8 CH annunciator for FLT CONT light.
    ``3. Maximum flap setting to be used is Flap 20 degrees.''

    -(3) Within 50 hours time-in-service after the effective date of 
this AD, perform an operational test to identify the unserviceable 
HSTA or horizontal stabilizer trim control unit (HSTCU) and replace 
it with a serviceable unit, in accordance with Bombardier Alert 
Service Bulletin A600-0645, dated January 11, 1995 (for Model CL-
600-1A11 series airplanes), or A601-0443, dated January 11, 1995 
(for Model CL-600-2A12 and CL-600-2B16 series airplanes), as 
applicable. Replacement of the unserviceable unit with a serviceable 
unit constitutes terminating action for the requirements of 
paragraphs (c)(1) and (c)(2) of this AD. Following such replacement, 
exercise of the pitch trim system may be discontinued and the 
limitation may be removed from the AFM.
    -(4) Thereafter at intervals not to exceed 100 hours time-in-
service repeat the functional test of the HSTA brake as specified in 
paragraph (a) of this AD.
    -(d) For airplanes on which the stabilizer over-travel is shown 
to be more than 1 degree during the functional test required by 
paragraph (a) of this AD, accomplish the requirements of paragraphs 
(d)(1) and (d)(2) of this AD.
    -(1) Prior to further flight, perform an operational test to 
identify the unserviceable HSTA or HSTCU and replace it with a 
serviceable unit, prior to further flight, in accordance with 
Bombardier Alert Service Bulletin A600-0645, dated January 11, 1995 
(for Model CL-600-1A11 series airplanes), or A601-0443, dated 
January 11, 1995 (for Model CL-600-2A12 and CL-600-2B16 series 
airplanes), as applicable.
    -(2) Thereafter at intervals not to exceed 100 hours time-in-
service repeat the functional test of the HSTA brake as specified in 
paragraph (a) in this AD.
    -(e) 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York ACO.

    -(f) 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.
    -(g) The operational test and replacement shall be done in 
accordance with Bombardier Alert Service Bulletin A600-0645, dated 
January 11, 1995, or Bombardier Alert Service Bulletin A601-0443, 
dated January 11, 1995, as applicable. This incorporation by 
reference was approved by the Director of the Federal Register in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be 
obtained from Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 
6087, Station Centreville, Quebec H3C 3G9, Canada. Copies may be 
inspected at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the FAA, New York Aircraft 
Certification Office, Engine and Propeller Directorate, 10 Fifth 
Street, Third Floor, Valley Stream, New York; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.
    -(h) This amendment becomes effective on September 12, 1995.

    Issued in Renton, Washington, on August 15, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-20632 Filed 8-25-95; 8:45 am]
BILLING CODE 4910-13-U