61-21-04 DOUGLAS: Amdt. 347 Part 507 Federal Register October 13, 1961. Applies to All DC-8 Aircraft Equipped With JT3C, JT4 and Conway Engine Installations (Models DC-8-11, -12, -31, -32, -33, -41, -42 and -43). \n\n\tCompliance required as soon as the installation of available parts can be scheduled but not later than the next 600 hours' time in service after October 13, 1961, unless an operator has obtained approval from the Chief, Engineering and Manufacturing Branch, Federal Aviation Agency Western Region for an alternative compliance program. \n\n\tAs a result of numerous recent failures of the flexible hoses in the discharge lines of the engine-driven hydraulic pumps, unless already accomplished, certain hoses and clamps approved as part of the basic type design must be removed and replaced as follows: \n\n\t(a) Replace hoses an indicated or with FAA approved equivalents: \n\n\nAirplane Serial Nos. \nRemove Hose P/N\nInstall Hose P/N\n\n\n\nAll DC-8-11 and -12 aircraft(JT3-C engines)\n5654402-10-6129\n5765665-10-6129\nAll DC-8-21, -31, -32 and -33 aircraft (JT4 engines) except S/N 45422-45431, 45433 and 45602-45606\n5654402-10-6724\n5765665-10-6824\n45422-45431, 45433 and 45602-45606\n618-10-0676\n624663-10-0676\nAll DC-8-41, -42 and -43 aircraft (Conway engines)\n5654402-10-5700\n5765665-10-5700\n\n\t(b) Replace clamps, P/N 4365431D21C, as used with hoses removed per (a), with clamps listed in Douglas DC-8 Service Bulletin No. 29-37, Revision No. 4, dated November 6, 1961 (or later issue), or with equivalent FAA-engineering approved clamps. The replacement clamps shall be installed in the manner and positions described in Service Bulletin No. 29-37. \n\n\t(Douglas DC-8 Service Bulletin No. 29-37, pertains to this same subject.) \n\n\tThis directive effective October 13, 1961. \n\n\tRevised December 6, 1961.