AD 97-25-11 R1

This amendment revises an existing airworthiness directive (AD), applicable to certain Bombardier Model CL-600-2B16 series airplanes, that currently requires disabling the remote fuel/defuel panel in the cockpit; and provides for an optional modification of the remote fuel/defuel panel, which would terminate the requirement to disable the panel. This amendment reduces the applicability of the existing AD. This amendment is prompted by reports of in-flight failure of the panel that resulted when a circuit breaker on a battery bus opened due to insufficient current flow capacity. The actions specified in this AD are intended to prevent the circuit breakers from opening during flight, which could result in irreversible loss of engine indicating and fuel quantity systems in the cockpit.

Direct final rule; confirmation of effective date

97-25-11 R1 BOMBARDIER, INC. (Formerly Canadair): Amendment 39-10425. Docket
98-NM-21-AD. Revises AD 97-25-11, Amendment 39-10235.
Applicability: Model CL-600-2B16 series airplanes, serial numbers 5113, 5117, 5127, 5134,
5136, 5144, 5150, 5151, 5166, 5174, 5175, 5176, 5179, and 5188; 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 request approval
for an alternative method of compliance in accordance with paragraph (c) of this AD. The request
should include an assessment of the effect of the modification, alteration, or repair on the unsafe
condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request
should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent the circuit breakers on the battery bus from opening during flight, which could
result in irreversible loss of engine indicating and fuel quantity systems in the cockpit, accomplish
the following:

(a) Within 5 days after December 23, 1997 (the effective date of AD 97-25-11, amendment
39-10235), disable the remote fuel/defuel panel, in accordance with Bombardier Service Bulletin
SB TUS-28-20-02-1, dated November 13, 1997.

(b) Modification of the remote fuel/defuel panel in accordance with Bombardier Service
Bulletin SB TUS-28-20-02, dated November 13, 1997, permits the remote fuel-defuel panel to be
enabled, and constitutes terminating action for the requirements of paragraph (a) of this AD.

(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, Los Angeles Aircraft
Certification Office (ACO), 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, Los Angeles ACO.

NOTE 2: Information concerning the existence of approved alternative methods of compliance
with this AD, if any, may be obtained from the Los Angeles ACO.

(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.

(e) The actions shall be done in accordance with Bombardier Service Bulletin
SB TUS-28-20-02-1, dated November 13, 1997; or Bombardier Service Bulletin SB TUS-28-20-02,
dated November 13, 1997. This incorporation by reference was approved previously by the Director
of the Federal Register as of December 23, 1997 (62 FR 64519, December 8, 1997). Copies may be
obtained from Bombardier Aviation Services, 1255 East Aeropark Boulevard, Tucson, Arizona
85706. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue,
SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft
Certification Office, 3960 Paramount Boulevard, Lakewood, California; or at the Office of the Federal
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) This amendment becomes effective on June 25, 1998.

The FAA published this direct final rule with request for comments in the Federal Register on March 27, 1998 (63 FR 14804). The FAA uses the direct final rulemaking procedure for a non-controversial rule where the FAA anticipates that there will be no adverse public comment. This direct final rule advised the public that no adverse comments were anticipated, and that unless a written adverse comment, or a written notice of intent to submit such an adverse comment, was received within the comment period, the regulation would become effective on June 25, 1998. No adverse comments were received, and thus this notice confirms that this final rule will become effective on that date. Issued in Renton, Washington, on May 5, 1998.