Undercarriage.

         The CL-28 undercarriage is based on the Britannia design. To achieve a considerable weight saving, American wheels and brakes are used and the bogie beam has been entirely redesigned.

        In addition, an arrangement utilizing the drag strut and torque scissor links has been developed so that the bogie beam is rotated mechanically as the gear retracts, thus eliminating the hydraulic jacks and sequence valves of the original arrangement.

        It is interesting to note that the large undercarriage forgings in the CL-28 were among the first aircraft applications for the new 7079S high aluminurn alloy.

        The electrical system of the CL-28 the pioneer category. It is an automatically paralleling constant frequency AC system with power being supplied by four 40-KVA alternators one driven from each engine through a constant speed gear box.

        Power is delivered through a main ring bus system to six distribution substations located at the forward and aft end of the fuselage and in each engine nacelle.

        Direct current power requirements are provided by selenium or silicon rectifiers. Because of the newness of this type of system, a good many of, the automatic control and protective devices had to be specially developed by the equipment manufacturers.

        In addition, the over-all electrical system so complex that it was necessary to construct a full-scale mockup of the system in the laboratory so that the operation of the system under similar conditions and the effect of the protective and control could be adequately checked.

Electronic Design.

         Much of the electrical power generated is required to operate the many different electronics devices. These units cover the whole spectrum of radio frequency and micro-wave regimes and require altogether 41 different antennae. Locating these antennae about the airplane so as to obtain satisfactory operation, and at the same time to avoid mutual interference, was a problem in itself.

        Most of the electronics development was, in fact, in the antenna field. In addition to the fin cap antenna mentioned before, a low silhouette (for low drag) compass antenna system was designed and one very large and several smaller radomes had to be designed and developed.

        To support this work, a 1/50th scale model was built to study antenna radiation patterns, a 115 scale model, covered in copper mesh, was used to measure impedances and snatch the antennae to the airplane and a number of full-scale mock-ups were required for wave guide development and specific transmission interference studies.

        In addition to all of the "black box" tactical equipment, the CL-28 is capable of carrying a variety of offensive stores. For tactical reasons these may be employed in a number of sequences and modes.

        The electrical stores selection and release system designed to meet these requirements is comparable to a small telephone exchange.

        Another interesting item in the armament field was the development of a pneumatic ejector for dispensing large stores. Stores of this type had previously only been dropped, but to conserve bomb bay space ejection was decided upon. To ensure that this approach was practical, a prototype installation was satisfactorily tested on an early stage in co-operation with the RCAF and RCN, under service conditions in another aircraft.

Crew Accommodation.

         From a tactical point of view, the crew of the airplane is of prime importance and a great deal of attention has been paid to the arrangement of the crew stations and the orientation of the various members to ensure maximum efficiency.

        The CL-28 is provided with a complete Flight Engineer's station, from which the engineer is capable of controlling power, monitoring engine condition and controlling the normal and emergency aircraft systems. Provision of the engineer's station allows the pilots to be relieved of many of the routine operating chores and leaves them free to concentrate on flying and tactical problems. As mentioned previously, particular attention has been paid to visibility from the cockpit to facilitate visual searching.

        Additional visual searching stations are provided in the nose and on each beam.

        Since the different tactical units in the airplane are linked in various ways, all of this equipment has been grouped together in one compartment so that the various operators can be in close contact with one another and can transfer readily from one mode of operation to another.

        All of the tactical jobs require close attention and concentration, and as a result crew fatigue is a major problem. To combat this problem, extensive crew rest facilities are provided in the airplane.

        The rest facilities which include a seated rest and dining area, an extensive galley with provisions for refrigerated storage and cooking of food, bunks, etc., are grouped together and isolated from the operating and tactical areas of the airplane. Even the color scheme in this area has been chosen to be conducive to rest.

        Another item which is normally a major cause of crew fatigue is noise. A great deal of effort has been expended in developing a sound-proofing treatment which will ensure an acceptable degree of comfort in the various compartments. Considerable laboratory work was done to determine the most effective and lightest means of sound-proofing.

        The treatment adopted consists of the use of adhesive aluminum foil for skin panel damping, and various amounts of fibreglass for sound absorption. To check the accuracy of soundproofing calculations a full-scale section of the fuselage was built and sound-proofed and internal noise measurements made while this test section was located adjacent to the ground test power unit.

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