COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Oxygen Systems AD/OXY/16 Puritan-Bennett Oxygen Mask 11/97 Applicability: Puritan-Bennett sweep-on crew oxygen masks with the following part numbers: 114321-01 114321-15 114321-16 114322-01 114322-02 114322-03 114322-05 114323-01 114622-01 114622-02 114623-01 114623-02 These items may have Puritan-Bennett cone and seal assemblies, part numbers 210543 and 210543-01 manufactured or repaired from 1 August 1996 to 31 July 1997 inclusive, fitted. Note: This equipment may be fitted to any aircraft. Requirement: 1. Replace any cone and seal assembly referenced in this airworthiness directive (AD) with an approved assembly not covered by this AD. 2. As of the effective date of this AD no aircraft may be equipped with any Puritan- Bennett oxygen mask that has the cone and seal assembly, part numbers 210543 and 210543-01, manufactured or repaired between 1 August 1996 and 31 July 1997 inclusive, fitted. Note: 1. FAA AD 97-18-03 Amdt 39-10113 refers. Note: 2. Puritan-Bennett Service Bulletin 3500-97-14, dated 7 August 1997, specifies identification and replacement of the part numbers 210543 and 210543-01. Compliance: Within 7 days after effective date of this directive. This airworthiness directive becomes effective on 9 October 1997. Background: FAA has advised that there may be a risk of failure of the ultrasonic weld on the cone and seal assembly of the oxygen mask with consequent reduced oxygen flow through the mask, which could result in the crew not being able to obtain oxygen in an emergency situation. This AD is intended to prevent that occurrence.