60-11-10: Tab Nuisance Bracket

60-11-10 VICKERS: Amdt. 148 Part 507 Federal Register May 10, 1960. Applies to All Viscount Model 745D Aircraft (Pre-modification D.2013 Parts (C), (J), (D), and (K) Standard) and All Viscount 810 Series Aircraft (Pre-modification FG.237 Parts (D) an (K) Standard). Compliance required at next removal of rudder trim tab and/or elevator spring tab, but not later than June 1, 1961. To preclude the possibility of inadvertent interchange of Pre-mod. D.2013 and FG. 237 rudder trim tab and elevator spring tab torque tube assemblies, Vickers Modification D.2918 (700 Series) and FG.1671 (800/810 Series) must be incorporated. This modification insures that the upper rudder trim tab torque tube assembly cannot be connected to the elevator spring tab and the elevator spring tab torque assembly cannot be connected to the rudder trim tab in the upper position. Incorporation of this modification on 700 Series aircraft is accomplished by installation of a nuissance bracket, P/N 70123-359 or equivalent, fitted to the tabs at the point of attachment of the relevant short (Pre-mod. D.2013) skewbars. On Model 810 Series aircraft, the long skewbar introduced by Mod. FG.237 is incorporated in the basic design of the right elevator trim tab. The left elevator anti-balance tab and the spring tab are operated by an external rod system to which Mod. FG.237 is not applicable. Since the rudder tab has a short skewbar, of Pre-mod. FG.237 standard, fitted at the upper position, it is required that installation of the nuissance bracket of Mod. FG.1671 or equivalent be made as a positive safeguard against incorrect assembly. (Vickers-Armstrongs Modification Bulletins D.2918 (700 Series) and FG.1671 (800/810 Series) cover this subject.)