92-15-10 BRITISH AEROSPACE: Amendment 39-8304. Docket No. 91-NM-278-AD. Supersedes AD 91-01-02, Amendment 39-6846.
Applicability: British Aerospace Model BAC 1-11 200 and 400 series airplanes, certificated in any category.
Compliance: Required as indicated, unless accomplished previously.
To prevent erroneous stick shake and stick push occurrences, which could adversely affect the controllability of the airplane, accomplish the following:
(a) Within 600 hours time-in-service or within 120 days after January 28, 1991 (the effective date of AD 91-01-02, Amendment 39-6846), whichever occurs first, measure the voltage and frequency outputs of Static Inverters No. 1 and No. 2, in accordance with the Accomplishment Instructions in British Aerospace Alert Service Bulletin 27-A-PM6005, Issue 1, dated March 28, 1990, or Issue 2, dated June 17, 1991. If the measured voltage and/or frequency do not conform with the tolerances as detailed in the Maintenance Manual, Paragraph E, "Stall Protection - Simulated Flight Condition Check," prior to further flight, remove the inverter from the airplane and recalibrate it in accordance with the service bulletin.
(b) Repeat the measurements required by paragraph (a) of this AD at the later of the times specified in subparagraphs (b)(1) and (b)(2) of this AD:
(1) Within 600 hours time-in-service or 4 months after performing the measurement required by paragraph (a) of this AD, whichever occurs first; or
(2) Within 100 hours time-in-service after the effective date of this AD.
(c) After performing the measurements required by paragraph (b) of this AD, repeat the measurements thereafter at intervals not to exceed 600 hours time-in-service or 4 months, whichever occurs first.
(d) Within 12 months after the effective date of this AD, install Modification PM6005 in the number 1 and 2 inverters, in accordance with British Aerospace Service Bulletin 27-PM6005, dated June 11, 1991. Installation of Modification No. PM6005 in the number 1 and 2 inverters constitutes terminating action for the requirements of this AD.
(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, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate.
NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch.
(f) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.
(g) The measurements and recalibrations shall be done in accordance with British Aerospace Alert Service Bulletin 27-A-PM6005, Issue 1, dated March 28, 1990, or British Aerospace Alert Service Bulletin 27-A-PM6005, Issue 2, dated June 17, 1991. The modifications shall be done in accordance with British Aerospace Alert Service Bulletin 27-PM6005, 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 British Aerospace, PLC, Librarian for Service Bulletins, P.O. Box 17414, Dulles International Airport, Washington, D.C. 20041-0414. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington; or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, DC.
(h) This amendment becomes effective on September 8, 1992.