83-24-04 BRITISH AEROSPACE: Amendment 39-4776. Applies to Model BAC 1-11 200 and 400 series airplanes, certificated in all categories. To prevent collapse of the nose landing gear, accomplish the following, unless previously accomplished:
A. For pre-modification PM5766 up/down lock jacks:
(1) Tonks spring discs - P/N AK43-1283.
(i) Must be replaced prior to the accumulation of 4,000 landings or within 500 landings after the effective date of this AD, whichever comes later.
(ii) Must be functionally tested in accordance with paragraphs 2.3 and 2.4 of Service Bulletin 32-A-PM5191, Issue 5, dated May 15, 1981, prior to the accumulation of 4,000 landings or within 100 landings after the effective date of this AD, whichever comes later.
(2) Terry discs - P/N AB43-2579 and Spring Master discs - P/N AB43-2745:
(i) Must be replaced prior to the accumulation of 8,000 landings or within 500 landings after the effective date of this AD, whichever comes later.
(ii) Must be functionally tested in accordance with paragraphs 2.3 and 2.4 of the service bulletin prior to the accumulation of 6,000 landings or within 500 landings after the effective date of this AD, whichever comes later; and thereafter at intervals not to exceed 500 landings, until replaced in accordance with paragraph A(2)(i), above.
B. For post-modification PM5766 up/down lock jacks:
(1) Tonks spring discs - P/N AK43-1283.
(i) Must be replaced prior to the accumulation of 8,000 landings or within 500 landings after the effective date of this AD, whichever comes later.
(ii) Must be functionally tested in accordance with paragraphs 2.3 and 2.4 of the service bulletin prior to the accumulation of 4,000 landings or within 500 landings after the effective date of this AD, whichever comes later; and thereafter at intervals not to exceed 500 landings, until replaced in accordance with paragraph B(1)(i), above.
(2) Terry discs - P/N AB43-2579 and Spring Master Discs - P/N AB43- 2745.
(i) Must be replaced prior to the accumulation of 10,000 landings or within 500 landings after the effective date of this AD, whichever comes later.
(ii) Must be functionally tested in accordance with paragraphs 2.3 and 2.4 of the service bulletin prior to the accumulation of 8,000 landings or within 500 landings after the effective date of this AD, whichever comes later; and thereafter at intervals not to exceed 500 landings, until replaced in accordance with paragraph B(2)(i), above.
C. Terminating action for this AD is accomplished by incorporation of helical coil springs into the up/down lock jack, BAe Modification 32-PM5191.
D. For the purpose of complying with this AD, subject to acceptance by the assigned FAA maintenance inspector, the number of landings may be determined by dividing each airplane's hours time in service by the operator's fleet average time from takeoff to landingfor the airplane type.
E. 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.
F. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD.
This amendment becomes effective January 9, 1984.