[Federal Register Volume 59, Number 195 (Tuesday, October 11, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-25059]


[[Page Unknown]]

[Federal Register: October 11, 1994]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-155-AD]

 

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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain Canadair Model CL-
600-2B19 series airplanes, that currently requires a revision to the 
Airplane Flight Manual (AFM) to restrict altitude and airspeed 
operations of the airplane under certain conditions of hydraulic system 
failure. This action would add a requirement to remove certain shear 
pins and install certain new shear pins on the elevator flutter 
dampers, and replace certain shear pins at repetitive intervals. This 
proposal is prompted by the development of a temporary repair that 
entails repetitive replacement of discrepant pins in a timely manner to 
prevent failure of the pins. The actions specified by the proposed AD 
are intended to prevent undampened vibration of the elevators in normal 
cruise conditions; when combined with hydraulic system failures, this 
condition could result in reduced controllability of the airplane.

DATES: Comments must be received by December 6, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-155-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, 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, 181 
South Franklin Avenue, Valley Stream, New York.

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:

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 94-NM-155-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. 94-NM-155-AD, 1601 Lind Avenue SW., Renton, Washington 
98055-4056.

Discussion

    On January 3, 1994, the FAA issued AD 94-01-09, amendment 39-8791 
(59 FR 1471, January 11, 1994), applicable to certain Canadair Model 
CL-600-2B19 (Regional Jet Series 100) series airplanes, to require a 
revision to the Limitations Section of the FAA-approved Airplane Flight 
Manual (AFM) to restrict altitude and airspeed operations of the 
airplane under certain conditions of hydraulic system failure. That 
action was prompted by a report of sheared-off shear pins found on one 
airplane's elevator dampers. The requirements of that AD are intended 
to prevent undampened vibration of the elevators in normal cruise 
conditions; when combined with hydraulic system failures, this 
condition can result in reduced controllability of the airplane.
    Since the issuance of that AD, Bombardier, Inc., has developed a 
temporary repair, which involves removing the existing shear pins and 
installing new shear pins on the elevator flutter dampers, and then 
replacing the shear pins at repetitive intervals. The intent of this 
temporary repair is to replace discrepant pins in a timely manner in 
order to prevent the failure of the pins. (The manufacturer is 
currently developing a permanent modification.) 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.
    Bombardier has issued Canadair ``Regional Jet'' Service Bulletin 
S.B. 601R-27-017, dated May 12, 1994, which describes procedures for 
accomplishing a temporary repair that entails the removal of shear pins 
having part number (P/N) HST22DU8-13, and the installation of new shear 
pins having P/N 601R24063-2501, on the elevator flutter dampers. This 
service bulletin also describes procedures for replacement of the new 
shear pins at repetitive intervals. Transport Canada Aviation, which is 
the airworthiness authority for Canada, classified this service 
bulletin as mandatory and issued Canadian Airworthiness Directive CF-
93-32R1, dated August 12, 1994, 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 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 supersede AD 94-01-09 to 
require removal of existing shear pins and installation of certain new 
shear pins on the elevator flutter dampers; and to require replacement 
of shear pins at repetitive intervals. The actions would be required to 
be accomplished in accordance with the service bulletin described 
previously.
    The proposed AD would also continue to require the previously-
required revision to the Limitations Section of the FAA-approved 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.
    The FAA estimates that 19 airplanes of U.S. registry would be 
affected by this proposed AD.
    The AFM revision that was previously required by AD 94-01-09, and 
retained in this proposal, takes approximately 1 work hour per airplane 
to accomplish, at an average labor rate of $55 per work hour. Based on 
these figures, the total cost impact of the AFM revision requirement on 
U.S. operators is estimated to be $55 per airplane. The FAA estimates 
that all affected U.S. operators have previously accomplished this 
requirement; therefore, the future cost impact of this requirement is 
minimal.
    The removal, installation, and replacement of shear pins that would 
be required by this proposal would take approximately 5 work hours per 
airplane to accomplish, at an average labor rate of $55 per work hour. 
Required parts would be supplied by the manufacturer at no cost to 
operators. Based on these figures, the total cost impact of these 
proposed requirement on U.S. operators is estimated to be $5,225, or 
$275 per airplane.
    The total cost impact figures discussed above are 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 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. 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 removing amendment 39-8791 (59 FR 
1471, January 11, 1994), and by adding a new airworthiness directive 
(AD), to read as follows:

    Bombardier, Inc. (Formerly Canadair): Docket 94-NM-155-AD. 
Supersedes AD 94-01-09, Amendment 39-8791.

    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 undampened vibration of the elevators in normal 
cruise conditions which, when combined with hydraulic system 
failures, could result in reduced controllability of the airplane, 
accomplish the following:
    (a) Within 30 days after January 26, 1994 (the effective date of 
AD 94-01-09, amendment 39-8791), 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. 

                    Single Hydraulic System Failure                     
------------------------------------------------------------------------
                                                        Airspeed limit  
              Altitude limit (maximum)                     (maximum)    
------------------------------------------------------------------------
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 below...............................  252 KIAS          
------------------------------------------------------------------------


                    Double Hydraulic System Failure                     
------------------------------------------------------------------------
                                                        Airspeed Limit  
              Altitude Limit (maximum)                     (maximum)    
------------------------------------------------------------------------
10,000 feet-........................................  200 KIAS          
------------------------------------------------------------------------

    (b) For airplanes having serial numbers 7003 through 7044, 
inclusive: Within 45 days after the effective date of this AD, 
remove shear pins having part number (P/N) HST22DU8-13 that are 
installed on the elevator flutter dampers, and install new shear 
pins having P/N 601R24063-2501, in accordance with Canadair Regional 
Jet Service Bulletin S.B. 601R-27-017, dated May 12, 1994. 
Thereafter, prior to the accumulation of 800 flight hours on any 
shear pin having P/N 601R24063-2501, replace it with a new shear pin 
having P/N 601R24063-2501.
    (c) 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, Standardization Branch, ANM-113, 
FAA, Transport Airplane Directorate. Operators shall submit their 
requests through an appropriate FAA Principal Maintenance Inspector, 
who may add comments and then send it to the Manager, 
Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (d) 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 October 4, 1994.
S.R. Miller, Acting Manager,
Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 94-25059 Filed 10-7-94; 8:45 am]
BILLING CODE 4910-13-U