AD 94-24-02

This amendment supersedes an existing airwothiness directive (AD), applicable to certain Canadair Model CL-600-2B19 series airplanes, that currently requires a revision to the FAA- approved Airplane Flight Manual (AFM) to restrict altitude and airspeed operations of the airplane under certain conditions of hydraulic system failure. This amendment requires the removal of all elevator flutter dampers and requires a revision to the AFM that advises the flight crew of the need to perform daily checks to verify proper operation of the elevator control system. This amendment is prompted by reports that the installation of the stronger shear pins may jam or restrict movement of the elevator. The actions specified in this AD are intended to prevent failure of the lugs and/or pins, which may increase the likelihood of jamming or restricting movement of the elevator and the resultant adverse affect on the controllability of the airplane.

94-24-02 BOMBARDIER, INC. (FORMERLY CANADAIR): Amendment 39-9075. Docket 94-NM- 219-AD. Supersedes AD 94-01-09, Amendment 39-8791.

Applicability: Model CL-600-2B19 (Regional Jet Series 100) series airplanes having serial numbers 7003 through 7054 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 (c) 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 failure of lugs and/or pins, which may increase the likelihood of jamming or restricting movement of the elevator and the resultant adverse affect on 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 2: The restrictions described inthe AFM Temporary Revision (TR) RJ/30, dated December 16, 1993, 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.

NOTE 3: When TR RJ/30, dated December 16, 1993, has been incorporated into 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 TR RJ/30.

SINGLE HYDRAULIC SYSTEM FAILURE

Altitude Limit Airspeed 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 252 KIAS
and below
__________________________________________________

DOUBLE HYDRAULIC SYSTEM FAILURE

Altitude Limit Airspeed Limit
(Maximum) (Maximum)
10,000 feet 200 KIAS
________________________________________________

SINGLE HYDRAULIC SYSTEM FAILURE

Altitude Limit Airspeed 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 252 KIAS
and below
__________________________________________________

DOUBLE HYDRAULIC SYSTEM FAILURE

Altitude Limit Airspeed Limit
(Maximum) (Maximum)

10,000 feet 200 KIAS __________________________________________________

(b) Within 7 days after the effective date of this AD, accomplish the requirements of paragraphs (b)(1) and (b)(2) of this AD.

(1) Remove all elevator dampers in accordance with Canadair Regional Jet Alert Service Bulletin S.B. A601R-27-041, dated October 28, 1994.

(2) Revise the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to include the following, which advises the flight crew of daily checks to verify proper operation of the elevator control system. Revision of the AFM may be accomplished by inserting a copy of this AD in the AFM.

"Elevator, Before Engine Start (First Flight of Day)
(1)Elevator...................................Check Travel range (to approximately 1/2 travel) using each hydraulic system in turn, with the other hydraulic systems depressurized."

NOTE 4: The daily check described in TR RJ/40, dated October 28, 1994, meets the requirements of this paragraph. Therefore, inserting a copy of TR RJ/40 in lieu of this AD in the AFM is considered an acceptable means of compliance with this paragraph.

NOTE 5: When TR RJ/40, dated October 28, 1994, has been incorporated into 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 TR RJ/40.

(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, 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 6: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO.

(d) The removal shall be done in accordance with Canadair Regional Jet Alert Service Bulletin S.B. A601R-27-041, dated October 28, 1994. 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 Centre-ville, Montreal, Quebec H3C 3G9, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the New York Aircraft Certification Office, FAA, Engine and Propeller Directorate, 181 South Franklin Avenue, Room 202, Valley Stream, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(e) This amendment becomes effective on December 14, 1994.

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 Manaul (AFM) to restrict altitude and airspeed operations of the airplane under certain conditions of hydraulic system failure.

Since the issuance of that AD, Bombardier, Inc., developed a temporary repair, which involves removing the existing shear pins and installing new, stronger shear pins on the elevator flutter dampers, and replacing the shear pins at repetitive intervals. Consequently, on October 4, 1994, the FAA issued a notice of proposed rulemaking (NPRM) that proposed to supersede AD 94-01-09 and require the installation of the temporary repair developed by Bombardier, Inc. The proposed actions were intended to prevent reduced controllability of the airplane.

However, since the issuance of that NPRM, Transport Canada Aviation, which is the airworthiness authority for Canada, has notified the FAA that the shear pins and lugs of the elevator flutter damper sheared off of two Model CL-600-2B19 series airplanes. Investigation revealed that the shear pins installed in the incident airplanes were the stronger pins associated with the "temporary repair" developed previously by Bombardier. In light of this, the FAA has determined that the installation of stronger shear pins and lugs of the elevator flutter damper, as proposed by the NPRM, may jam or restrict movement of the elevator. Accordingly, the FAA intends to withdraw that NPRM in a separate rulemaking action.

Further investigation indicates that removal of the flutter dampers from those airplanes will eliminate the risk of jamming or restricting movement of the elevator. The FAA has determined that removal of the flutter dampers will not adversely affect controllability of the airplane, since AD 94- 01-09 requires a revision to the Limitations Sections of the FAA-approved Airplane Flight Manual (AFM) that restricts altitude and airspeed of the airplane. The FAA finds that those restrictions, which are retained in the requirements of this AD, will avert flutter conditions.

Failure of the lugs and/or shear pins of the elevator flutter damper, if not corrected, can result in the increased likelihood of jamming or restricting the movement of the elevator, which would adversely affect the controllability of the airplane.

Bombardier has issued Canadair "Regional Jet" Alert Service Bulletin S.B. A601R-27-041, dated October 28, 1994, which describes procedures for removal of the flutter dampers. Transport Canada Aviation classified this service bulletin as mandatory and issued Canadian Airworthiness Directive CF-94-21, dated October 28, 1994, in order to assure the continued airworthiness of these airplanes in Canada.

This airplane model is manufactured inCanada 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, this AD supersedes AD 94-01-09, to require removal of all elevator flutter dampers. This action is required to be accomplished in accordance with the alert service bulletin described previously.

This AD also requires a revision to the FAA-approvedAirplane Flight Manual (AFM) that advises the flight crew of the need to perform daily checks to verify proper operation of the elevator control system. This AD also retains the requirement from AD 94-01-09 to require a revision to the AFM that restricts altitude and airspeed operations under conditions of single or double hydraulic failure.

[NOTE: 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. Under these circumstances, at least one operator appears to have incorrectly assumed that its airplane was not subject to an AD. On the contrary, 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 areain 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 added to this final rule to clarify this 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 tothis rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 94-NM-219-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. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. 39.13 - [Amended]
2. Section 39.13 is amended by removing amendment 39-8791 (59 FR 1471, January 11, 1994), and adding the following new airworthiness directive (AD) to read as follows: