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MOVIE FILES
SIG’s Kadet trainer was one of the first, and one of the best, RC trainers ever designed. Through the 30+ years it has been available, the .40-sized “Kadet” has taught the mysteries of airspeed control, proper attitude and basic aerobatics to tens of thousands of new RC pilots. The old Kadet still lives on in both the updated Kadet LT-40 kit and the Kadet LT-40 ARF. Both versions are still helping to train more RC pilots, as they are two of the easiest trainers to fly.
A few years ago SIG introduced a larger version of this proven airframe as the Kadet Senior ARF. The 70” wingspan of the .40-sized Kadet is increased to 80”. The wing area grows from 910 sq. in. to 1,200 sq. in. The larger airplane weighs 7.75 lbs, just 29 % more than the smaller, original version. The much larger wing and moderate weight increase result in a low “wing loading”, only 15 ounces per square foot of wing area. These are very good numbers for so large a plane.
The Kadet Senior’s low wing loading is just one reason it is well suited to the training roll. The very large tail surfaces, (302 sq. in. for the stabilizer and 105 sq. in. for the vertical fin) combine with the large fuselage area behind the wing to keep the Kadet Senior pointed straight ahead, even during “deep stalls”. This “yaw” stability at low speeds helps the student pilot to keep the nose pointed the right way during slow flight and landing approaches.
Because the Kadet Senior has good yaw stability, the ailerons can be made larger than is usual on a trainer plane. Large ailerons give more control response but can also cause an effect known as “adverse yaw”. Adverse yaw happens because the “down” aileron of a flat bottom wing has more air drag then the “up” aileron and this causes the plane’s nose to actually point AWAY from the direction of the turn at slow speeds. The Kadet Senior did not exhibit any trace of this condition except during post-stall recovery.
The Kadet Senior ARF builds along the standard ARF format. While it is not a Ready To Fly plane, it takes only about 30 hours to build. The builder must supply the .60 size engine and a four-channel radio with five servos (the ailerons use two servos).
 
Photo 1 Photo 2
Photo 3
As Photo 1 shows, the fuselage servos mount in the traditional ARF manner, using standard balsa pushrods. The aileron servos are mounted in each wing half just in front of the ailerons, (the dark wing areas in Photo 8). Each half of the two-piece wing slides onto a metal wing spar and a steel positioning rod (Photo 2). Front tabs lock into a notch in the fuselage (Photo 3), locking the wing halves together. Two nylon bolts lock the wing’s rear together and hold the wing onto the fuselage. The 80 “ wing transports as easily as a 40 “ wing because of this unique construction.
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