Canadair CP - 107 Argus The Canadair CP - 107 Argus ( CL - 28 ) was a marine reconnaissance aircraft designed and manufactured by Canadair for the Royal Canadian Air Force ( RCAF ) and Canadian Forces ( CF ) . In its early years , the Argus was reputedly the finest anti - submarine patrol bomber in the world . The Argus served throughout the Cold War in the RCAF ' s Maritime Air Command and later the CF ' s Maritime Air Group and Air Command . Design and development . Canadair began work on the CL - 28 in April 1954 and at the time it was the largest aircraft built in Canada . The hybrid design was derived from the Bristol Britannia transport , having the same wings , tail surfaces and landing gear except for being " Americanized " - meaning that it used the same general design , but changing the British materials and standard parts for North American ones . The fuselage was completely redesigned by Canadair , going from the pressure cabin of the Britannia to a non - pressurised one with bomb bays fore and aft of the wings . The powerplant was also changed from the Bristol Proteus turbo - prop engines to Wright R - 3350 compound ( piston ) engines , which had lower fuel consumption necessary for extended missions at low level . Testing . From July 1960 , a CP - 107 Argus underwent hot weather testing at Eglin AFB , Florida . Since the Canadian climate is comparatively cool , even in mid - summer , a team of 35 RCAF officers and airmen have come to Eglin for six weeks to evaluate the performance of their four - engined Argus patrol craft in a hot - weather environment . Squadron Leader Garnet W . Ovans pointed out they could have tested the Argus in a much warmer location , ' but we picked Eglin because it also had the necessary humidity range , and especially because of the extensive testing facilities here . The APGC project officer for the test of the Argus is Major Charles E . Dougan , of the Directorate of Strategic Systems Test . While at Eglin , the 35 - man RCAF crew will collect high - temperature performance data on the Argus , including fuel consumption rates , takeoff and landing distances , maintenance techniques , and functional checks of the armament systems . Operational history . The Argus replaced the RCAF Lancaster and Neptune aircraft types previously flown in the maritime roles . One of the most effective anti - submarine warfare ( ASW ) aircraft of its day , the Argus was a mainstay for the RCAF . A large amount of equipment was carried , including : search radar , sonobuoys , electronic counter measures ( ECM ) , explosive echo ranging ( EER ) and magnetic anomaly detector ( MAD ) . Up to 8 , 000 lb ( 3 , 632 kg ) of weapons could be carried in the bomb bays , including torpedoes , bombs , mines and depth charges . A flight crew of fifteen consisting of three pilots , three navigators ( Observer Long range ) , two flight engineers and 6 radio officers ( observer rad ) until the early sixties when the crew included both commissioned officers ( tactical navigator / radio navigator and non commissioned officers ( observers ) , the number of which was dependent on the mission . Four crew bunks and a galley were provided to extend the efficiency of the crew on long patrols ( average 18 hrs ) . The CL - 28 had an endurance of approximately 26½ hours with full armament . An Argus flown by 407 Maritime Patrol Squadron held the Canadian military record of slightly over 31 hours for the longest flight by an unrefuelled aircraft . This record stood for almost 20 years until broken by the Rutan Voyager experimental aircraft which circled the globe unrefuelled . The principal difference between the Mark I and Mark II was primarily in the different navigation , communication and tactical electronic equipment fitted internally . Externally , the Mk II exhibited a redesigned smaller nose radome and additional ECM antenna above the fuselage . The Argus flew its last service mission on 24 July 1981 , and was replaced by the CP - 140 Aurora .