62-26-04 LOCKHEED: Amdt. 514 Part 507 Federal Register December 5, 1962. Applies to All Model 188A and Model 188C Aircraft.
Compliance required as indicated.
To permit early detection of cracks in both the closed and open section type elevator balance weight arms and to assure rework of uncracked arms and replacement of cracked arms, the failure of which could cause jamming of the elevator or adversely affect protection against flutter, the following shall be accomplished:
(a) Unless already accomplished within the last 75 hours' time in service prior to the effective date of this AD, all elevator balance weight arms of the closed (square tube) type shall, within the next 100 hours' time in service following the effective date of this AD and at intervals thereafter not to exceed 175 hours' time in service from the last inspection, be inspected in the manner prescribed in (c). Any closed type arm found to be cracked shall be replaced prior to further flight with an uncracked closed type arm of the same part number, with an uncracked open type arm of the proper part number as prescribed by Lockheed Field Service Letter FS/249931L or with an FAA engineering approved replacement arm. The replacement shall be accomplished in accordance with Lockheed Service Bulletin 88/SB-567, Revision 1, or FAA engineering approved equivalent.
(b) Unless already accomplished within the last 250 hours' time in service prior to the effective date of this AD, all elevator balance weight arms of the open (C-section) type shall, within the next 100 hours' time in service following the effective date of this AD and at intervals thereafter not to exceed 350 hours' time in service from the last inspection, be inspected in the manner prescribed in (c). Any open type arm found to be cracked shall be replaced prior to further flight with an uncracked arm of the same part number or with an FAA engineering approved equivalent arm. The replacement shall be accomplished in accordance with Lockheed Service Bulletin 88/SB-567, Revision 1, or FAA engineering approved equivalent.
(c) Conduct close visual inspection of all external exposed surfaces of both types of arms and of the inner surfaces of open type arms in areas where external surfaces are hidden by clips. The close visual inspections shall be made with a magnifying glass or magnifying mirror of at least 3X magnification, with the elevator in full up position and with all elevator access doors at the trailing edge of the horizontal stabilizer, in the open position.
(d) Within 350 hours' time in service after the effective date of this AD, all balance weight arms inspected per (a) and (b) and found to be uncracked shall, unless already accomplished, be reworked in the manner described by paragraphs B(2) through B(6) of Lockheed Service Bulletin 88/SB-567, Revision 1, or in an FAA engineering approved equivalent manner.
(e) Closed type replacement arms installed per (a) and closed typeuncracked arms reworked per (d) are subject to the inspection for cracks in accordance with (c) at intervals not to exceed 175 hours' time in service. Open type replacement arms installed per (a) or (b) and open type uncracked arms reworked per (d) are subject to the inspection for cracks in accordance with (c) at intervals not to exceed 350 hours' time in service. (FAA engineering approved equivalent replacement arms installed per (a) or (b) will be subject to such special inspections as may be prescribed by FAA in conjunction with the approval of the use of such arms.)
(f) The periodic inspections of (a), (b), and (e) may be discontinued after compliance with either of the following:
(1) Modify elevator assembly in accordance with sections 2.A through 2.W of Lockheed Service Bulletin 88/SB-566C or later FAA-approved revision; or
(2) If elevator assembly has been modified before February 3, 1966 in accordance with sections 2.A through 2.S of Lockheed Service Bulletin 88/SB-567B, inspect the horizontal stabilizer throughout the elevator travel for interference.
(i) If interference exists, modify the elevator assembly in accordance with sections 2.A through 2.W of Lockheed Service Bulletin 88/SB-567C or later FAA-approved revision.
(ii) If no interference exists, no further action is necessary.
(g) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Aircraft Engineering Division, FAA Western Region, 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 increase for such operator.
(Lockheed Field Service Letters FS/249931L dated September 9, 1960, FS/250044L dated November 28, 1960, Lockheed Service Bulletins 88/SB-567, revision 1, and 88/SB-567B, cover this same subject.)
This supersedes the Airworthiness Directive on the same subject issued and made effective by telegram dated November 23, 1962.
This directive effective December 4, 1962.
Revised May 26, 1964.
Revised February 5, 1966.