AD 91-15-11

91-15-11 BOEING: Amendment 39-7075. Docket No. 91-NM-128-AD. Supersedes AD 91-11-08.

Applicability: Model 767-200 and 767-300 series airplanes, listed in Boeing Alert Service Bulletin 767- 28A0036, dated May 3, 1991, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent, during dry pump operation, a potential ignition source in the center wing tanks due to a broken pumping unit diffuser ring, accomplish the following:

(a) Within the next 30 days after June 30, 1991 (the effective date of Amendment 39-7005), inspect the center wing tank pumping units, part number 5006286, in accordance with the procedures of Boeing Alert Service Bulletin 767-28A0036, dated May 3, 1991.

(1) If diffuser assembly brazed joints are found to be acceptable, reidentify and reinstall the pumping unit in accordance with the service bulletin.

(2) If the brazed joints are determined to be discrepant as indicated by the inspection procedure, repair or replace the diffuser assembly in accordance with the service bulletin prior to reinstallation of the pumping unit.

(b) Except for center wing tank pumping units that are inspected and found to be acceptable in accordance with paragraph (a)(1) of this AD, within 30 days after the effective date of this AD, inspect the airplane or airplane records to determine if the center wing tank pumping units are suspect, in accordance with Boeing Alert Service Bulletin 767-28A0036, Revision 1, dated June 11, 1991.

(1) If a pumping unit is suspect, prior to further flight, inspect the diffuser assembly brazed joints in accordance with the service bulletin.

(i) If the diffuser assembly brazed joints are found to be acceptable, reidentify and reinstall the pumping unit in accordance with the service bulletin.

(ii) If the brazed joints are determined to be discrepant as indicated by the inspection procedure, repair or replace the diffuser assemblyin accordance with the service bulletin prior to reinstallation of the pumping unit.

(2) If the pumping unit is not one listed as suspect, no further action is required.

(c) In lieu of performing the inspection, repair, and/or replacement described in paragraphs (a) and (b) of this AD, deactivate the center wing fuel tank in accordance with Boeing Alert Service Bulletin 767-28A0036, dated May 3, 1991, or Revision 1, dated June 11, 1991. The tank may be reactivated only following completion of the inspections, repairs, and/or replacement required by paragraphs (a) and (b) of this AD.

(d) Within 45 days after the effective date of this AD, submit a report of findings of discrepancies detected by the inspection required by paragraphs (a) and (b) of this AD, to the Manager, Seattle Manufacturing Inspection District Office, ANM-108S, FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington 98055-4056; fax (206) 227-1181. Include the pump serial numberand affected airplane line or serial number in the report. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (P.L. 96- 511) and have been assigned OMB Control Number 2120-0056.

(e) An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Seattle ACO.

(f) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

(g) The inspection, repair, and replacement requirements shall be done in accordance withBoeing Alert Service Bulletin 767-28A0036, Revision 1, dated June 11, 1991. 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 Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. Copies may be inspected at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington, or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, D.C.

Airworthiness Directive 91-15-11, supersedes AD 91-11-08, Amendment 39-7005. This amendment (39-7075, AD 91-15-11) becomes effective on August 2, 1991.