Article: A Tutorial on a Truly Canadian Airplane for Training Jet Pilots

  • Image of Canadair Tutor, CL-41

    Altitude, Winter, 2015

    The origin of the Tutor jet trainer dates back to 1956, when Canadair, on its own initiative, undertook an ambitious plan to design an airplane from concept to finished product.

    Canadair called this airplane the CL-41, adding the word “Tutor” to its model description to emphasize its pilot training role.

    The Royal Canadian Air Force followed through with an order for 190 airplanes once it was convinced that the CL-41 Tutor would meet its requirements for a jet trainer. The CL-41 Tutor made its prototype debut flight in 1960. The first production Tutor was completed at Canadair’s Montreal factory and delivered to the RCAF in December, 1963. The RCAF took delivery of its last Tutor in September, 1966. Canadair built another 20 Tutors for the Malaysian air force before ending production in 1967.

    The RCAF gave its Tutors the model designation of CT-114, and it is this term that will be used in the remainder of this article.

    CT-114 Tutors served as the RCAF’s elementary jet trainer for almost four decades until 2000, when they were replaced by the CT-156 Harvard IIs (built by Raytheon) and CT-155 Hawks (built by British Aerospace Systems).

    At present, 24 Tutors remain in service. The Snowbirds Air Demonstration Team of 431 Squadron at Moose Jaw flies nine Tutors in a typical air show.

    The first Tutors were modified for aerobatic service in the late 1960s. These modifications included a smoke generating device, a paint scheme to enhance the spectator experience, and engine adjustments to enhance response in low-level flying.

    Canadair’s challenge was to design an airplane that excelled in its teaching role. According to Ron Pickler and Larry Mulberry in their 1995 history, Canadair: The First 50 Years, the challenge was to design an aircraft with forgiving spin characteristics, “because it is vital that a pilot learn why an aircraft spins and how to recover from an unplanned spin, a training airplane must be able to get into a spin easily, and always spin predictably, and be able to recover easily.”

    The Canadair design team made scale models and evaluated their spin characteristics in wind tunnel tests. These tests showed that “fore and aft movement of the vertical fin was critical to good spin entry and recovery. If the fin was too far forward, the model wouldn’t enter the spin; too far back and it would not recover. When they got the correct position, they moved the tailplane up the fin until they got the best spin mode. Then they cut off the fin above the tailplane and this gave the aircraft its distinctive ‘T’ tail.”

    Image of Canadair Tutors, CL-41

    The CT-114 Tutor is described as a conventional all-metal, low-wing, single-engine, turbojet airplane designed for training pilots. It has side-by-side ejection seats for instructor and student in a pressurized and air conditioned cockpit. Most of the services are electrically operated, but the landing gear, wing flaps, speed brakes, nose wheel steering and wheel brakes are hydraulically operated. The Tutor was certified for Instrument Flight Rule (IFR) conditions and is equipped with instrumentation for navigation, instrument and night flying instruction. The CT-114 is powered by a single Orenda J-85 CAN-40 turbojet with 2,950 lbs of thrust, providing the airplane with a service ceiling of 42,200 feet and a fuel range of 2.5 hours.

    The CT-114 in its trainer role was designed to the needs of both the beginner and the advanced student. The Tutor, according to a 1967 brochure published by Canadair, “has a performance that ranges from a stalling speed of 70 knots – thus being a safe slow machine for the early training stages, to a maximum level speed of 416 knots (Mach .72) at 20,000 feet–which is fast enough to provide the advanced student with experience in the effects of compressibility and training in high-speed navigation.”

    Canadair emphasized that this range of instructional performance was achieved without undermining safety, which consisted of “an automatic escape system which permits ejection at zero altitude and 90 knots; a bird-proof windshield; longitudinal beams incorporated in the lower fuselage which provide the cockpit area with strength capable of resisting vertical crash loads of up to 8G; a seating installation capable of withstanding crash loads of 32G; and fuselage-mounted, crash-resistant fuel cells located near the centre of gravity so that the aircraft has consistent spin and recovery characteristics in all fuel weights.” In essence, the Tutor was a plane designed to survive wear and tear from being handled by trainee pilots.

    During the early stages of design, there was considerable discussion whether the instructor and student should be positioned in tandem or side-by-side; the side-by-side configuration was ultimately chosen. In 2014, the spring edition of the CAHS Journal published a retrospective article written by Bill Upton, a former Canadair staff member and aviation historian, on the CT-114 Tutor. Upton made the following observation about the cockpit layout: “The side-by-side seating configuration … provided an ideal and efficient instructional environment … the student would sit on the left side of the cockpit with the instructor occupying the right seat. The obvious advantages to this seating arrangement permitted the instructor to effortlessly observe and assess the student’s actions and reactions during all phases of training, and the student could learn by directly observing the actions of the instructor. All flying controls and basic flight instruments were duplicated, and unobstructed vision was available to each pilot under all conditions.”

    The CAHS article went on to say that “a long wheel base and wide-track landing gear was provided for in the initial design to provide good directional stability during take-off, landing and taxiing, an important consideration for the inexperienced student pilot.”

    Upton’s article also said that the Tutor crew “accessed the cockpit via a jettisonable, rear-sliding, multi-framed canopy, and sat upon the same type of ejection seats used in the F-86 Sabre. This trainer was to provide the student with all he needed to operate the Canadair-built Sabre; all instruments and controls on both sides of the cockpit were similar to those fitted in the famed RCAF day fighter.”

    How much did the CT-114 cost? In the CAHS Journal article, Upton stated that the “initial basic price for the airframe, less engine, to prospective customers was set at approximately $160,000 with an all-up, fly-away airplane costing somewhere in the range of $195,000 to $200,000.” This was a price estimate that applied to the Tutor in the three years before the prototype made its debut flight in 1960 and when the project was still a private venture of Canadair’s own initiative.

    Image of Canadair Tutor, CL-41, being presented to Aviation Museum at ceremony

    This article originally appeared in the Winter, 2015 edition of Altitude.

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