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.

Variants

 * Argus Mk 1 : Long-range maritime reconnaissance aircraft for the RCAF. This aircraft was fitted with an American APS-20 radar in a chin-mounted radome. (13 built)
 * Argus Mk 2 : Long-range maritime reconnaissance aircraft for the RCAF. This aircraft was fitted with a British ASV-21 radar in a chin-mounted radome. (20-built)

Operators

 * Royal Canadian Air Force
 * No. 404 Squadron RCAF
 * No. 405 Squadron RCAF
 * No. 407 Squadron RCAF
 * No. 415 Squadron RCAF
 * No. 449 Squadron RCAF
 * Canadian Forces
 * Canadian Forces

Survivors

 * 10717 at Greenwood Military Aviation Museum, Greenwood, Nova Scotia
 * 10718 at Comox Air Force Museum, British Columbia
 * 10732 at National Air Force Museum of Canada, Trenton, Ontario
 * 10739 at Summerside Airport, Prince Edward Island
 * 10742 at Canada Aviation and Space Museum, Ottawa