[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