80-12-05 R2 BRITISH AEROSPACE, INC. (formerly Hawker Siddeley Aviation, Ltd.): Amendment 39-3789 as amended by Amendment 39-4390 is further amended by Amendment 39- 4580. Applies to Models HS/DH/BH 125 airplanes, all series, certificated in all categories.
Compliance is required as indicated.
To detect and correct cracks in the bridge casting of the nose landing gear drag stay assembly and prevent possible nose landing gear collapse, accomplish the following:
(a) Upon the accumulation of 2000 landings on the bridge casting or within the next 100 landings after the effective date of this AD, whichever occurs later, and thereafter at intervals not to exceed 900 landings on the bridge casting from the last inspection or every two years, whichever occurs first, inspect and rework or replace as necessary the bridge casting P/N 25UN49A in accordance with Section 2A "Accomplishment Instructions" of British Aerospace Service Bulletin 32-184, Revision 2, dated October 20, 1980, or an FAA-approved equivalent.
(b) Prior to the installation of modified bridge casting P/N 25UN49AD held as spares or in store, accomplish the inspection and rework specified in paragraph (a) of this AD.
NOTE: British Aerospace Modification 252677 introduces a new production standard of bridge casting P/N 25UN49AD, which incorporates "radiusing," polishing, and special surface treatment of the bridge area.
(c) For modified bridge castings, P/N 25UN49AD, continue to inspect in accordance with paragraph 2.A., "Accomplishment Instructions," of British Aerospace Service Bulletin 32- 184, Revision 3, dated June 24, 1982, or an FAA-approved equivalent.
(d) For purposes of complying with this AD, for airplanes for which no records exist that indicate the number of landings the bridge casting has accumulated, the number of landings may be estimated by using the total airplane time in service in hours on a 1-to-1 ratio.
(e) Upon request of the operator, an FAA maintenance inspector may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increased inspection interval requested for that operator.
(f) Alternate means of compliance which provide an equivalent level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.
The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1).
Amendment 39-3789 became effective June 16, 1980.
Amendment 39-4390 became effective June 8, 1982.
This Amendment 39-4580 becomes effective March 16, 1983.