AD 97-25-11

Effective December 23, 1997.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of December 23, 1997.

Comments for inclusion in the Rules Docket must be received on or before January 7, 1998.

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 97-NM-286-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

The service information referenced in this AD may be obtained from Bombardier Aviation Services, 1255 East Aeropark Boulevard, Tucson, Arizona 85706. This information may be examined 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.

Brett Portwood, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone (562) 627-5350; fax (562) 627-5210.

The FAA has received reports of three in-flight occurrences of loss of all engine indicating and fuel quantity systems in the cockpit on certain Bombardier Model CL-600-2B16 series airplanes. In each case, the internal fuel/defuel panel had been left in the ``ON'' position for an extended period of time. When the panel was switched off, all engine and fuel quantity indications were lost; subsequent attempts to cycle the panel power back on were unsuccessful. Investigation revealed an opened circuit breaker. It was determined that, if power to the remote fuel/defuel panel is left on for up to approximately one hour, the controlling circuit breaker on the battery bus will have insufficient capacity to hold the current flow and, as a result, may open during flight. This condition, if not corrected, could result in irreversible loss of engine indicating and fuel quantity systems in the cockpit.

Bombardier has issued Service Bulletin SB TUS-28-20-02-1, dated November 13, 1997, which describes procedures for disabling the remote fuel/defuel panel in the cockpit. Bombardier also has issued Service Bulletin SB TUS-28-20-02, dated November 13, 1997, which describes procedures for modifying the remote fuel/defuel panel; accomplishment of this modification eliminates the need to disable the panel. The modification involves replacing certain circuit breakers for the fuel/ defuel power and fuel quantity displays with new circuit breakers, and adding three 4-pole relays to allow switching of fuel quantity when the internal fuel panel is selected.

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.

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 is being issued to prevent loss of engine indicating and fuel quantity systems in the cockpit in the event a circuit breaker opens during flight. This AD requires disabling the remote fuel/defuel panel in the cockpit. This AD also provides for an optional modification of this panel, which would terminate the requirement to disable the panel. The actions are required to be accomplished in accordance with the service bulletins described previously.

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.

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 to this rule must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 97-NM-286-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.

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

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:

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.