AD Amdt-39-9325

[Federal Register Volume 60, Number 145 (Friday, July 28, 1995)]
[Rules and Regulations]
[Pages 38668-38670]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 95-18585]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-116-AD; Amendment 39-9325; AD 95-13-04]


Airworthiness Directives; Bombardier Model CL-600-2B19 (Regional 
Jet Series 100) Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment 
adopting Airworthiness Directive (AD) 95-13-04 that was sent previously 
to all known U.S. owners and operators of certain Bombardier Model CL-
600-2B19 (Regional Jet Series 100) series airplanes by individual 
letters. This AD requires a revision to the Airplane Flight Manual to 
prohibit the use of mach trim and to add speed restrictions if the 
autopilot is disengaged or inoperative. This AD also requires 
installation of an associated placard. 

[[Page 38669]]
This amendment is prompted by deficiencies that were discovered during 
a recent review of vendor documentation of the horizontal stabilizer 
trim control unit. The actions specified by this AD are intended to 
prevent such deficiencies, which could result in a nose-up trim runaway 
when a single component in the mach trim circuits fails.

DATES: Effective August 14, 1995, to all persons except those persons 
to whom it was made immediately effective by priority letter AD 95-13-
04, issued on June 16, 1995, which contained the requirements of this 
amendment.
    Comments for inclusion in the Rules Docket must be received on or 
before September 26, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-116-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The applicable service information may be obtained from 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 11581; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

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

SUPPLEMENTARY INFORMATION: On June 16, 1995, the FAA issued priority 
letter AD 95-13-04, applicable to certain Bombardier Model CL-600-2B19 
(Regional Jet Series 100) series airplanes. Transport Canada Aviation, 
which is the airworthiness authority for Canada, recently notified the 
FAA that, during a recent Canadair review of vendor documentation of 
the horizontal stabilizer trim control unit (HSTCU), certain 
deficiencies were discovered. The reliability of the HSTCU was found to 
be lower than anticipated due to circuit design deficiencies. When such 
deficiencies exist in the HSTCU, and a single component in the mach 
trim circuits fails, a nose-up trim runaway could occur.
    Bombardier has issued Canadair Regional Jet Temporary Revision No. 
TR RJ/43 to the Airplane Flight Manual (AFM). This temporary revision 
advises the flightcrew that the use of mach trim is prohibited and that 
speed restrictions must be applied if the autopilot is disengaged or 
inoperative. Transport Canada Aviation issued Canadian airworthiness 
directive CF95-08, dated June 8, 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, 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 the unsafe condition described is likely to exist or develop 
on other airplanes of the same type design registered in the United 
States, the FAA issued priority letter AD 95-13-04 to require a 
revision to the Limitations Section of the FAA-approved AFM to prohibit 
the use of mach trim and to add speed restrictions if the autopilot is 
disengaged or inoperative. The actions are required to be accomplished 
in accordance with the temporary revision to the AFM previously 
described.
    In addition, the FAA finds that in order to ensure flightcrew 
awareness, the installation of a placard is necessary to advise the 
flightcrew of the operations restrictions discussed previously.
    This AD is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual letters 
issued on June 16, 1995, to all known U.S. owners and operators of 
certain Bombardier Model CL-600-2B19 (Regional Jet Series 100) series 
airplanes. These conditions still exist, and the AD is hereby published 
in the Federal Register as an amendment to section 39.13 of the Federal 
Aviation Regulations (14 CFR 39.13) to make it effective as to all 
persons.

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-116-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 

[[Page 38670]]
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, 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 is revised to read as 
follows:

    Authority: 49 USC 106(g), 40101, 40113, 44701.


Sec. 39.13  [Amended]

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

Bombardier, Inc. (formerly Canadair) 95-13-04: Amendment 39-9325. 
Docket 95-NM-116-AD.

    Applicability: Model CL-600-2B19 (Regional Jet Series 100) 
series airplanes, serial numbers 7003 and subsequent, certificated 
in any category.
    Compliance: Required as indicated, unless accomplished 
previously. To prevent a nose-up trim runaway, accomplish the 
following: (a) Within 24 hours after the effective date of this AD, 
accomplish the requirements of paragraphs (a)(1), (a)(2), and (a)(3) 
of this AD. (1) Install a placard adjacent to the primary flight 
display next to the airspeed limitation placard, to read:
    ``USE OF MACH TRIM IS PROHIBITED. IF THE AUTOPILOT IS DISENGAGED 
OR INOPERATIVE, RESTRICT SPEED TO 250 KIAS OR 0.7 MACH.''
    (2) Revise the Limitations section of the FAA-approved Airplane 
Flight Manual (AFM) to include the following information. The 
requirements of this paragraph may be accomplished by inserting a 
copy of this AD, or Canadair Regional Jet Temporary Revision No. TR 
RJ/43, into the AFM.
    ``USE OF MACH TRIM IS PROHIBITED. IF THE AUTOPILOT IS DISENGAGED 
OR INOPERATIVE, RESTRICT SPEED TO 250 KIAS OR 0.7 MACH.''

    Note 1: When the temporary revision has been incorporated in the 
general revisions of the AFM, the general revisions may be inserted 
in the AFM, provided the information contained in the general 
revision is identical to that specified in Canadair Regional Jet 
Temporary Revision No. TR RJ/43.

    (3) Revise the Limitations Section of the FAA-approved AFM to 
include the following information. The requirements of this 
paragraph may be accomplished by inserting a copy of this AD into 
the AFM.
    ``Prior to the accomplishment of Bombardier Alert Service 
Bulletin S.B. A601R-27-054, dated June 12, 1995, when the Mach trim 
system is disengaged, the ``MACH TRIM'' caution message will be 
displayed on the Engine Indication and Crew Alerting System (EICAS), 
and the Mach trim engage/disengage switch ``INOP'' legend will be 
illuminated. The EICAS message may be scrolled out of view prior to 
takeoff, but the switch ``INOP'' light will remain illuminated.''
    (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, 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.

    (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.
    (d) This amendment becomes effective on August 14, 1995, to all 
persons except those persons to whom it was made immediately 
effective by priority letter AD 95-13-04, issued on June 16, 1995, 
which contained the requirements of this amendment.

    Issued in Renton, Washington, on July 24, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-18585 Filed 7-27-95; 8:45 am]
BILLING CODE 4910-13-U