[Federal Register Volume 59, Number 217 (Thursday, November 10, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-26721]


[[Page Unknown]]

[Federal Register: November 10, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-NM-213-AD; Amendment 39-9055; AD 94-22-06]

 

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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Bombardier Model CL-600-2B19 series airplanes, 
that requires modification of the stall protection system (SPS) input 
wiring; a revision to the FAA-approved Airplane Flight Manual (AFM) to 
specify that a pre-flight check of the slip/skid indications must be 
conducted prior to engine start; and modification of the stall 
protection computer (SPC) to accept restored dual attitude and heading 
reference system (AHRS) input. This amendment is prompted by a report 
that the AHRS could send conflicting input to the SPC on the airplane. 
The actions specified by this AD are intended to prevent the loss of 
stall warning protection on the airplanes.

DATES: Effective December 12, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 12, 1994.

ADDRESSES: The service information referenced in this AD may be 
obtained from Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 
6087, Station Centreville, Montreal, Quebec H3C 3G9, Canada. This 
information may be examined at the Federal Aviation Administration 
(FAA), Transport Airplane Directorate, Rules Docket, 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; 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, 181 South Franklin 
Avenue, Room 202, Valley Stream, New York 11581; telephone (516) 791-
6427; fax (516) 791-9024.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Bombardier Model CL-600-
2B19 (Regional Jet Series 100) series airplanes was published in the 
Federal Register on March 4, 1994 (59 FR 10340). That action proposed 
to require modification of the stall protection system (SPS) input 
wiring; a revision to the Normal Procedures section of the FAA-approved 
Airplane Flight Manual (AFM) to specify that a pre-flight check of the 
slip/skid indications must be conducted prior to engine start; and 
modification of the attitude and heading reference system (AHRS) to 
restore the dual AHRS inputs to the SPC.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter requests that the FAA revise the final rule to 
indicate that it is not the AHRS that will be modified, but the stall 
protection computer (SPC). The FAA concurs, and has revised the 
preamble and paragraph (c) of the final rule to clarify its intent that 
the SPC be modified to restore the dual AHRS inputs to the SPC.
    The commenter also requests that the proposed compliance time of 6 
months for modification of the SPC, as specified in paragraph (c) of 
the proposed rule, be extended due to the complex nature of the SPC 
modification and the need to modify additional equipment to support the 
SPC change. The commenter proposes a target date of April 4, 1995, for 
accomplishment of the modification. As justification for this suggested 
extension, the commenter states that the SPC software will detect a 
loss of AHRS input to both SPC channels, and a ``STALL FAIL'' amber 
message will be displayed; additionally, the AFM defines abnormal 
procedures to be followed when loss of the SPS occurs. The commenter 
adds that there are several components in the SPS that can fail and 
cause the loss of stall protection on any one flight. The commenter 
believes that the loss of AHRS input is no worse than, and the system 
is just as reliable as, a system with two independent AHRS inputs.
    The FAA does not concur. Compliance times for AD's are normally 
based on a parameter related to failure of a particular component. The 
FAA has determined that there is no apparent direct relationship 
between the transmittal of conflicting input from the AHRS to the SPC 
(and subsequent loss of stall warning protection on the airplane) and a 
calendar date. Therefore, the FAA does not consider that the compliance 
time for modification of the SPC should be expressed in terms of a 
calendar date, as suggested by the commenter.
    Further, in developing a compliance time for this requirement of 
the rule, the FAA considered not only the safety implications, but the 
availability of required parts and the practical aspect of installing 
the required modification within a maximum interval of time allowable 
for all affected airplanes to continue to operate without compromising 
safety. In light of these items, the FAA finds that a compliance time 
of 6 months is appropriate. (Additionally, based on the effective date 
of this final rule, the compliance time for operators to perform the 
modification will fall close to the calendar date requested by the 
commenter.)
    A new paragraph (d) has been added to the final rule to clarify the 
FAA's intent that modification of the SPC constitutes terminating 
action for the AFM revision required by paragraph (b) of this AD. 
Therefore, once the SPC is modified, the AFM revision may be removed 
from the AFM.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    The FAA estimates that 9 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 2 work hours per 
airplane to accomplish the required actions, and that the average labor 
rate is $55 per work hour. The cost for required parts will be minimal. 
Based on these figures, the total cost impact of the AD on U.S. 
operators is estimated to be $990, or $110 per airplane.
    The total cost impact figure discussed above is based on 
assumptions that no operator has yet accomplished any of the 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.
    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.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it 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.


Sec. 39.13  [Amended]

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

94-22-06 Bombardier, Inc. (Formerly Canadair): Amendment 39-9055. 
Docket 93-NM-213-AD.

    Applicability: Model CL-600-2B19 (Regional Jet Series 100) 
series airplanes; serial numbers 7003 through 7026, inclusive; 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent the loss of stall warning protection on the airplane, 
accomplish the following:
    (a) Within 30 days after the effective date of this AD, modify 
the stall protection system (SPS) input wiring in accordance with 
Canadair Regional Jet Alert Service Bulletin A601R-34-028, Revision 
``A,'' dated October 22, 1993.
    (b) Prior to further flight after accomplishment of the 
modification required by paragraph (a) of this AD, revise the Normal 
Procedures section of the FAA-approved Airplane Flight Manual (AFM) 
by inserting the following into the AFM as facing page 04-20-13 
 to advise the flight crew that a pre-flight check of the slip/
skid indications must be accomplished as a ``Before Start'' item. 
This may be accomplished by inserting a copy of this AD into the 
AFM.
    ``Change step (4) within paragraph E, Before Start, to read as 
follows:

(4) EFIS
 Checked and Set

 Check that no annunciations are displayed on EFIS
 EFIS slip/skid indications
Normal
 Indications of a one-half (\1/2\) symbol width lateral 
deviation should be interpreted as an AHRS failure.

NOTE

 One-half (\1/2\) symbol width displacement corresponds to 
approximately one-half displacement on a conventional inclinometer.
 EFIS
 Set for Departure''

    Note 1: Insertion of Canadair Regional Jet Airplane Flight 
Manual CSP A-012, Temporary Revision RJ/26, dated October 21, 1993, 
in the Normal Procedures section of the AFM is an acceptable method 
of compliance with the requirements of paragraph (b) of this AD.

    (c) Within 9 months after the effective date of this AD, modify 
the stall protection computer (SPC) to accept restored dual attitude 
and heading reference system (AHRS) input, in accordance with a 
method approved by the Manager, New York Aircraft Certification 
Office (ACO), FAA, Engine and Propeller Directorate.
    (d) Modification of the SPC in accordance with paragraph (c) of 
this AD constitutes terminating action for the AFM revision required 
by paragraph (b) of this AD. Following accomplishment of that 
modification, the AFM revision may be removed from the FAA-approved 
AFM.
    (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 ACO. 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.

    (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 modification shall be done in accordance with Canadair 
Regional Jet Alert Service Bulletin A601R-34-028, Revision ``A,'' 
dated October 22, 1993. 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, 
Montreal, Quebec H3C 3G9, Canada. Copies may be inspected 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; or at the Office of the Federal Register, 
800 North Capitol Street, NW., suite 700, Washington, DC.
    (h) This amendment becomes effective on December 12, 1994.

    Issued in Renton, Washington, on October 24, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-26721; Filed 11-9-94; 8:45 am]
BILLING CODE 4910-13-U