AD 94-20-05 ACTIVE

This amendment adopts a new airworthiness directive (AD) that applies to certain Beech Aircraft Corporation (Beech) 1900 series airplanes. This action requires inspecting the hot battery bus fuse assembly for proper wiring, correcting the wiring if incorrect, and modifying the wiring to add a redundant power source for the hot battery bus. This action results from a report of the hot battery bus bar wrongly installed on the lower (load) side of the hot battery bus fuse assembly on one of the affected airplanes. Correct installation is the upper (power) side of the circuit. The actions specified by this AD are intended to protect from overloads to either circuit connected to the hot battery bus from overloads, which, if not protected, could result in loss of certain emergency equipment.

Final rule; request for comments

94-20-05 BEECH AIRCRAFT CORPORATION: Amendment 39-9033; Docket No. 94-CE-19-AD.

Applicability: The following model and serial number airplanes, certificated in any category:

Model
Serial Numbers
1900 UA-2 and UA-3
1901
1900C
UB-1 through UB-74 and UC-1 through UC-174
1900D
UE-1 through UE-87
C-12J (Military)
UD-1 through UD-6

Compliance: Required within the next 50 hours time-in-service after the effective date of this AD, unless already accomplished.

To protect either circuit connected to the hot battery bus from overloads, which, if not protected, could result in loss of certain emergency equipment, accomplish the following:

(a) Visually inspect the hot battery bus fuse assembly to ensure that the hot battery bus bar is mounted on the row of terminals located on top of the hot battery bus fuse assembly in accordance with paragraphs 1 through 3 in the ACCOMPLISHMENT INSTRUCTIONS section of Beech Service Bulletin (SB) No. 2562, dated August1994. If not mounted correctly, prior to further flight, reinstall the hot battery bus bar and reattach the wire harness in accordance with Beech SB No. 2562.

(b) Modify the wiring to add a redundant power source for the hot battery bus by accomplishing paragraphs 1, 2, and 4 through 12 of the ACCOMPLISHMENT INSTRUCTIONS section of Beech SB No. 2562, dated August 1994.

(c) 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.

(d) An alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Wichita Aircraft Certification Office (ACO), FAA, 1801 Airport Road, Room 100, Wichita, Kansas 67209. The request should be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and sendit to the Manager, Wichita ACO.

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

(e) The inspection and modification required by this AD shall be done in accordance with the instructions to Beech Service Bulletin No. 2562, dated August 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 Beech Aircraft Corporation, P.O. Box 85, Wichita, Kansas 67201-0085. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) This amendment becomes effective on October 14, 1994.

The FAA has received a report that the hot battery bus bar was wrongly installed on the lower (load) side of the hot battery bus fuse assembly on a Beech 1900 series airplane. Correct installation is the upper (power) side of the circuit. With the reported configuration, a single five amp fuse supplies electrical power to all the systems connected to the bus instead of (under the correct wiring configuration) the hot battery bus supplying each essential load independently through a fuse for each load. In normal conditions, an airplane operator would not notice the miswired hot battery bus bar until the single fuse is blown. This condition, if not detected and corrected, could result in the loss of electrical power to all emergency equipment connected to the hot battery bus. This equipment includes the left and right engine fire extinguisher bottles, the left and right fire wall shutoff valves, the cockpit emergency lighting, and the engine fire extinguisher indicator lights.

In addition, these airplanes currently are not equipped with a redundant power source for the emergency equipment receiving power from the hot battery bus. Under the present scenario, an internal battery problem could prevent the use of the emergency equipment because of no backup power sources for this equipment connected to the hot battery bus.

Beech has issued Service Bulletin (SB) No. 2562, dated August 1994, which specifies procedures for (1) inspecting the hot battery bus fuse assembly for proper wiring and correcting the wiring if incorrect, and (2) modifying the wiring to add a redundant power source for the hot battery bus.

After examining the circumstances and reviewing all available information related to the incidents described above, the FAA has determined that AD action should be taken in order to protect either circuit connected to the hot battery bus from overloads, which, if not protected, could result in loss of certain emergencyequipment.

Since an unsafe condition has been identified that is likely to exist or develop in other Beech 1900 series airplanes of the same type design, this AD requires the inspection and modification specified in Beech SB No. 2562, dated August 1994.

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for public prior 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 immediate flight safety and, thus, was not preceded by notice and opportunity to 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 should identify the Rules Docket number and be submitted in triplicate to the address specifiedabove. 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 notice must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket No. 94-CE-19-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 and that must be issued immediately to correct an unsafe condition in aircraft, and 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 (otherwise, an evaluation is not required). A copy of it, if filed, may be obtained from the Rules Docket.

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.

Section 39.13 - [AMENDED]
2. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Central Region, Office of the Assistant Chief Counsel, Attention: Rules Docket 94-CE-19-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

Information that relates to this AD may be obtained from the Beech Aircraft Corporation, P.O. Box 85, Wichita, Kansas 67201-0085. This information may also be examined at the FAA at the address above; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Mr. Harvey E. Nero, Aerospace Engineer, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Wichita, Kansas 67209; telephone (316) 946-4137; facsimile (316) 946-4407.