99-08-21  PURITAN-BENNETT AERO SYSTEMS COMPANY: Amendment 39-11130; Docket No. 98-CE-29-AD.

Applicability: Puritan-Bennett C351-2000 series passenger oxygen masks and portable oxygen masks, part numbers as listed below, that (1) have elastomer cure dates between September 1993 and March 1997; and (2) are installed in aircraft that are certificated in any category:

NOTE 1: This AD applies to each aircraft equipped with an oxygen mask 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 aircraft 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 (d) 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 in the body of this AD, unless already accomplished.

To prevent reduced oxygen consumption when passengers are required to use defective oxygen masks, which could result in passenger injury, accomplish the following:

(a) Within the next 6 calendar months after the effective date of this AD, inspect the passenger or portable oxygen masks for any tear in the face cushion in accordance with the ACCOMPLISHMENT INSTRUCTIONS section in Nellcor Puritan-Bennett Service Bulletin No. C351-2000-35-1, Revision 2, date of original issue: July, 1996; date of first revision: February, 1997; date of current revision: February, 1998. The face cushion is adjacent to the inner mask housing. If a tear is found, prior to further flight, replace or repair the mask in accordance with the service bulletin.

(b) As of the effective date of this AD, no person may install, in any aircraft, Puritan-Bennett C351-2000 series passenger oxygen masks and portable oxygen masks that are specified in the Applicability section of this AD, unless they have been inspected and found airworthy in accordance with paragraph (a) of this AD.

(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 aircraft to a location where the requirements of this AD can be accomplished.

NOTE 2: 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 replacement or repair required by this AD shall be done in accordance with Nellcor Puritan-Bennett Service Bulletin No. C351-2000-35-1, Revision 2, date of original issue: July, 1996; date of first revision: February, 1997; date of current revision: February, 1998. 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 Puritan-Bennett Aero Systems Company, 10800 Pflumm Road, Lenexa, Kansas 66215. Copies may be inspected at the FAA, Central Region, Office of the Regional 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 June 2, 1999.

FOR FURTHER INFORMATION CONTACT: Michael Imbler, Aerospace Engineer, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone: (316) 946-4147; facsimile: (316) 946-4407.