AD 97-04-15

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Pacific Scientific Company, HTL/Kin-Tech Division, fire extinguisher bottle cartridges (squibs), which may be installed on various transport category airplanes. This action requires a one-time inspection of the electrical receptacle of these fire extinguisher bottle cartridges and their mating connectors to detect the presence of aluminum foil in the area of the pins of the cartridges and the connectors, and removal of any aluminum foil that is present. This amendment is prompted by a report of failure of a fire extinguisher bottle cartridge to discharge as a result of the presence of aluminum foil in the cartridge, which caused electrical shorting of the pins. The actions specified in this AD are intended to prevent such shorting, which could result in failure of the fire extinguisher bottle to discharge when commanded.

Final rule; request for comments.

97-04-15 PACIFIC SCIENTIFIC COMPANY, HTL/KIN-TECH DIVISION: Amendment 39-9940. Docket 97-NM-27-AD.

Applicability: Fire extinguisher bottle cartridges (squibs) having part numbers (P/N) 13083-10 and -25; as installed in, but not limited to, the following airplane models, certificated in any category:

de Havilland Model DHC-7 series airplanes;

de Havilland Model DHC-8-100 and -300 series airplanes;

General Dynamics Convair Model 340, 440, and C-131 (military) series airplanes modified in accordance with Supplemental Type Certificate SA41100;

Lockheed Model 382 series airplanes; and

Sabreliner Model NA-265-60, -65, and -75A series airplanes.

NOTE 1: This AD applies to Pacific Scientific Company, HTL/Kin-Tech Division, fire extinguisher bottle cartridges having P/N's 13083-10 and -25, as installed on any airplane, regardless of whether the airplane has been otherwise 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 electrical shorting of the pins of the fire extinguisher bottle cartridge, which could result in failure of the fire extinguisher bottle to discharge when commanded, accomplish the following:

(a) Within 30 days after the effective date of this AD, accomplish the following:

(1) Pull the applicable circuit breakers and disconnect the electrical connector from any Pacific Scientific Company, HTL/Kin-Tech Division, fire extinguisher bottle cartridge (squib) having P/N 13083-10 or 13083-25. CAUTION: Prior to removing the electrical connector from the fire extinguisher bottle cartridge, ensure that the technician is grounded properly. Cartridges are electrostatic discharge (ESD) sensitive.

(2) Perform a one-time visual inspection of the electrical receptacle of the cartridge and its mating connector to detect the presence of aluminum foil in the area of the pins of the cartridge and the connector. The aluminum foil may have the appearance of solder. Remove any aluminum foil that is present.

(3) Reinstall the electrical connector, and reset the applicable circuit breakers.

NOTE 2: Inspections and removal of foil accomplished prior to the effective date of this AD in accordance with
Pacific Scientific Service Letter 97-018.BC, dated January 21, 1997, are considered acceptable for compliance with the requirements of this AD.

(b) As ofthe effective date of this AD, no person shall install on any airplane a Pacific Scientific Company, HTL/Kin-Tech Division, fire extinguisher bottle cartridge having P/N 13083-10 or 13083-25, unless the cartridge has been inspected in accordance with paragraph (a)(2) 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 3: 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) This amendment becomes effective on March 7, 1997.

The FAA received a report indicating that a Pacific Scientific Company, HTL/Kin-Tech Division, fire extinguisher bottle cartridge (squib) failed to discharge when commanded. Investigation revealed that aluminum foil was present in the cartridge, which caused electrical shorting of the pins. Aluminum foil is used to shunt the electrical pins of the cartridge for shipping purposes. The aluminum foil had not been removed properly prior to installation of the fire extinguisher bottle cartridge. Further investigation revealed that the electrical shorting condition existed on six other installed cartridges.

The affected cartridges are Pacific Scientific Company, HTL/Kin-Tech Division, fire extinguisher bottle cartridges having part numbers 13083-10 and 13083-25.

Electrical shorting of the pins in the fire extinguisher bottle cartridges, if not corrected, could result in failure of the fire extinguisher bottle to discharge when commanded.

FAA's Determination
The FAA has determined that, in order to ensure that the fire extinguisher bottle will discharge when commanded, Pacific Scientific Company, HTL/Kin-Tech Division, fire extinguisher bottle cartridges having part numbers 13083-10 and 13083-25 must be inspected to ensure that any aluminum foil is removed from the fire extinguisher bottle cartridges installed on the affected airplanes.

Explanation of the Requirements of the Rule
Since an unsafe condition has been identified that is likely to exist or develop on other components of the same type design installed on transport category airplanes, this AD is being issued to prevent electrical shorting of the pins of the fire extinguisher bottle cartridge, which could result in failure of the fire extinguisher bottle to discharge when commanded. This AD requires a one-time visual inspection of the electrical receptacle of certain Pacific Scientific Company, HTL/Kin-Tech Division, fire extinguisher bottle cartridges and their mating connectors to detect the presence of aluminum foil in the area of the pins of the cartridges and the connectors, and removal of any aluminum foil that is present.

Determination of Rule's Effective Date
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.

Comments Invited
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-27-AD." The postcard will be date stamped and returned to the commenter.

Regulatory Impact
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 thatthis 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."

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, 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. 106(g), 40113, 44701.

39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: