55-22-04 VICKERS-ARMSTRONG: Applies to All Viscount Model 745D Aircraft.
Compliance required as indicated.
Cracks have been found in the tailplane center section main spar extending along the lines of rivets attaching the web plate.
Accordingly, Vickers-Armstrong (Aircraft) Ltd. issued Preliminary Technical Leaflet No. 52 dated August 19, 1955, covering this subject. The British Air Registration Board considers Modification D.1384, the initial and repetitive inspections recommended therein mandatory in which the FAA concurs.
Aircraft complying with the limitations specified in PTL No. 52 will be considered serviceable.