[Federal Register Volume 59, Number 7 (Tuesday, January 11, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-344]


[[Page Unknown]]

[Federal Register: January 11, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 93-NM-230-AD; Amendment 39-8791; AD 94-01-09]

 

Airworthiness Directives; Canadair Model CL-600-2B19 ``Regional 
Jet'' Series 100 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 Canadair Model CL-600-2B19 ``Regional Jet'' Series 100 
airplanes. This action requires a revision to the Airplane Flight 
Manual (AFM) to limit altitude and airspeed operations of the airplane 
under certain conditions of hydraulic system failure. This amendment is 
prompted by a report of sheared-off shear pins found on one airplane's 
elevator dampers. The actions specified in this AD are intended to 
prevent undampened vibration of the elevators in normal cruise 
conditions when combined with hydraulic system failures, a condition 
which could result in reduced controllability of the airplane.

DATES: Effective January 26, 1994.
    Comments for inclusion in the Rules Docket must be received on or 
before March 14, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 93-NM-230-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.

FOR FURTHER INFORMATION CONTACT: Franco Pieri, Aerospace Engineer, 
Airframe Branch, ANE-172, New York Aircraft Certification Office, FAA, 
Engine and Propeller Directorate, 181 South Franklin Avenue, room 202, 
Valley Stream, New York 11581; telephone (516) 791-6221; fax (516) 791-
9024.

SUPPLEMENTARY INFORMATION: Transport Canada Aviation, which is the 
airworthiness authority for Canada, recently notified the FAA that an 
unsafe condition may exist on certain Canadair Model CL-600-2B19 
``Regional Jet'' Series 100 airplanes. Transport Canada Aviation 
advises that one operator of these airplanes found that the shear pins 
on the airplane elevator dampers had sheared off. This finding was made 
during a routine check of the airplane. The cause of the pin failure 
has not been determined. Failure of the shear pins on the elevator 
damper, if not detected and corrected, may lead to undampened vibration 
of the elevators during normal cruise conditions when combined with 
hydraulic system failures. This situation could result in reduced 
controllability of the airplane.
    This airplane model is manufactured in Canada and is type 
certificated for operation in the United States under the provisions of 
Sec. 21.29 of the Federal Aviation Regulations 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.
    In order to assure the continued airworthiness of these airplanes 
in Canada, Transport Canada Aviation issued a Canadian airworthiness 
directive on December 17, 1993, that restricts operation of these 
airplanes to certain altitude and airspeed limits under various 
conditions of hydraulic system failure. 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 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 undampened 
vibration of the elevators during normal cruise conditions in the event 
of hydraulic system failures, which could result in reduced 
controllability of the airplane. This AD requires a revision to the 
Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to 
restrict altitude and airspeed operations under conditions of single or 
double hydraulic failure.
    This is considered interim action until final action is identified, 
at which time the FAA may consider additional rulemaking.
    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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 93-NM-230-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 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 14 CFR part 
39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

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

    94-01-09  Canadair: Amendment 39-8791. Docket 93-NM-230-AD.

    Applicability: Model CL-600-2B19 ``Regional Jet'' Series 100 
airplanes; serial numbers 7003 and subsequent; certificated in any 
category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent undampened vibration of the elevators during normal 
cruise conditions in the event of hydraulic system failures, which 
could result in reduced controllability of the airplane, accomplish 
the following:
    (a) Within 30 days after the effective date of this AD, revise 
the Limitations Section of the FAA-approved Airplane Flight Manual 
(AFM) to include the following restrictions of altitude and airspeed 
operations under conditions of single or double hydraulic system 
failure; and advise the flight crew of these revised limits. 
Revision of the AFM may be accomplished by inserting a copy of this 
AD in the AFM.

    Note 1: The restrictions described in the AFM Temporary Revision 
(TR) RJ/30 meet the requirements of this paragraph. Therefore, 
inserting a copy of TR RJ/30 in lieu of this AD in the AFM is 
considered an acceptable means of compliance with this paragraph.

------------------------------------------------------------------------
   Altitude limit                                                       
      (maximum)                    Airspeed limit (maximum)             
------------------------------------------------------------------------
Single Hydraulic                                                        
 System Failure:                                                        
  31,000 feet.......  0.55 Mach (199 KIAS).                             
  30,000 feet.......  0.55 Mach (204 KIAS).                             
  28,000 feet.......  0.55 Mach (213 KIAS).                             
  26,000 feet.......  0.55 Mach (222 KIAS).                             
  24,000 feet.......  0.55 Mach (232 KIAS).                             
  22,000 feet.......  0.55 Mach (241 KIAS).                             
  20,000 feet and     252 KIAS.                                         
   below.                                                               
Double Hydraulic                                                        
 System Failure:                                                        
  10,000 feet.......  200 KIAS.                                         
------------------------------------------------------------------------


    (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 FAR 
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 January 26, 1994.

    Issued in Renton, Washington, on January 3, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-344 Filed 1-10-94; 8:45 am]
BILLING CODE 4910-13-U