AD 96-18-20

This amendment adopts a new airworthiness directive (AD), applicable to certain Piaggio Model P-180 airplanes, that requires replacement of outflow/safety valves with serviceable valves. This amendment is prompted by a report of cracking and subsequent failure of outflow safety valves in the pressurization system. The actions specified by this AD are intended to prevent such cracking and subsequent failure of the outflow/safety valves, which could result in rapid decompression of the airplane.

Final rule.

96-18-20 I.A.M. RINALDO PIAGGIO S.P.A.: Amendment 39-9747. Docket 95-NM-256-AD.

Applicability: Model P-180 airplanes; equipped with Allied Signal outflow/safety valves, as specified in Allied Signal Aerospace Service Bulletins 103742-21-4059 and 103744-21-4060, both dated March 31, 1995; 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 cracking and subsequent failure of the outflow/safety valves, which would result in rapid decompression of the airplanes, accomplish the following:

(a) Within 18 months after the effective date of this AD, replace the outflow/safety valve in accordance with Allied Signal Aerospace Service Bulletin 103742-21-4059 (for airplanes equipped with valves having part number 103742), or 103744-21-4060 (for airplanes equipped with valves having part number 103744), both dated March 31, 1995, as applicable.

(b) As of the effective date of this AD, no person shall install an outflow/safety valve having a part number and serial number identified in Allied Signal Aerospace Service Bulletin 103742-21-4059 (for airplanes equipped with valves having part number 103742) or 103744-21-4060 (for airplanes equipped with valves having part number 103744), both dated March 31, 1995, on any airplane unless that valve is considered to be serviceable in accordance with the applicable service bulletin.

(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) Thereplacement shall be done in accordance with Allied Signal Aerospace Service Bulletin 103742-21-4059, dated March 31, 1995; or Allied Signal Aerospace Service Bulletin 103744-21-4060, dated March 31, 1995; as applicable. 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 Allied Signal Aerospace, Technical Publications, Dept. 65-70, P.O. Box 52170, Phoenix, Arizona 85072-2170. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, 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 October 15, 1996.

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 Piaggio Model P-180 airplanes was published in the Federal Register on March 13, 1996 (61 FR 10292). That action proposed to require replacement of certain discrepant outflow/safety valves with serviceable valves.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Conclusion
The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact
The FAA estimates that 10 Model P-180 airplanes of U.S. registry will be affected by this AD, that it will take approximately 12 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. The parts manufacturer has advised that it will provide replacement parts at no cost to operators. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $7,200, or $720 per airplane.

The 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.

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.

For the reasons discussed above, I certify that this action (1) is nota "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. 106(g), 40113, 44701.

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