61-21-03 DOUGLAS: Amdt. 346 Part 507 Federal Register October 13, 1961. Applies to All DC-8 Series Aircraft. \n\n\tCompliance required within the next 150 hours' time in service after the effective date of this AD. \n\n\tAs a result of recent incidents which have shown the need for effective quantity indication of "reserve" hydraulic fluid in the system reservoir, the following must be accomplished: \n\n\tUnless already accomplished in accordance with FAA approved technical data, replace or modify in accordance with Douglas Service Bulletin No. DC-8 A29-40 (Reissue No. 1 or later) or FAA approved equivalent, the existing hydraulic quantity gage in the cockpit and the quantity transmitter in the fluid reservoir, to provide a system which will indicate the quantity of reserve hydraulic fluid in the reservoir down to approximately one gallon. The system indication error shall not exceed 10 percent. The dial on the quantity gage shall be marked in a manner which divides the total indicator range into three segments and identifies the three segments, as follows: \n\n\nSegment\nReserve Fluid Quantity in Reservoir\nNORMAL\nFull (11.5 gal.) to 4.9 gal.\nAUX.\n4.9 gal. to 1.5 gal.\nEMER.\n1.5 gal. to approx. 1.0 gal.\n\t\n\tThe exact quantities in gallons need not be marked on the quality indicator. "EMER." need not be shown provided that this segment is otherwise marked in a manner distinctly different from the other segments. \n\n\t(Douglas Service Bulletin No. DC-8 A29-40 (Reissue No. 1 or later) pertains to this same subject.) \n\n\tThis directive effective October 13, 1961.