Classic Remote Control Airplanes Kits Reviews – Kadet LT-25

by Shon Cioffi


  • Wing Span: 63 in (160 cm)
  • Wing Area: 724 sq in (4671 cm²)
  • Length: 40.4 in (103 cm)
  • Weight: 4.0 lbs (1.9 kg)
  • Engine:
    • .25 – .32 2 – cycle
    • (4.1 cc – 5.2 cc 2 – cycle)
    • .20 – .26 4 – cycle
    • (3.3 cc – 4.3 cc 2 – cycle)
  • 4 Servos required

The LT-25 was a project for me and my 7 year old son, Westlee. A very generous flyer gave my son a .25 two-stroke engine. I had promised to build a plane with Westlee for the past year so guided his decision away from a .25 size mustang to the Kadet LT-25. I had just finished building a Sig Somtin’ Extra and thought it was the greatest. I was wrong. The LT-25 is the best building experience I have ever had. To summarize the LT-25 it is the best kit I have ever seen, built, or owned. If my 7 year old can build it with supervision of dad with no difficulties, anybody can. WARNING! Do not buy this kit if you enjoy the challange of figuring out how to make all the pieces fit, enjoy building from bad plans with little or now instructions, and enjoy re-engineering poorly designed stuff.

Open the box and be careful taking out the parts as they will fall out. The LT-25 is all laser cut. Just for fun, they let you cut the center wing sheeting and trim the sticks. Other than that, all the parts fit perfectly with no trimming. We inventoried the kit and dug out the plans and instructions. For the next night or two Westlee and I read the instructions cover to cover like a bed time story. Westlee would allow no deviation from the plans so we built this LT-25 stock with no modifications. This was very hard on Dad as I have a tendency to want to “improve” things. I was able to get him to let me make the wing a bolt on instead of rubber bands but we had to follow the instructions from my 4 Star 40 to do that.

The construction section will be brief, as the instruction book is a photo-tutorial on how to build models and repeating it here would serve no purpose. I will cover the highlights. One note on glue, I used thin CA for everything except the landing gear block and firewall. These were glued in using yellow aliphatic resin. I used a very small tip so Westlee and I were careful not to use too much glue. The LT-25 is very light and has very little plywood. Avoid the temptation to add tri-stock or other strengthening measures. These will only add extra weight. The first month of flying, including one cartwheel, has shown that the stock version is more than strong enough.

We started with the wing. Layout the spars and notched trailing edge. Cut and glue the wing center sheeting to the spars. Set the notched sheer webs above the spars. The sheer webs are one piece, notched for each rib and run the full length of the wing. Slip all the ribs into the slots of the sheer webs. Add the diagonal wing braces between the ribs. The wing is now square, as there is no way to make a crooked wing with all the perfectly fit laser cut pieces in place. Even with no glue the wing is solid. Except the root rib glue all the ribs, trailing edge, sheer webs, and braces with thin CA. Glue the top spar and the leading edge in place. Use the dihedral gauge to angle the root rib and ca it in place. Sheet the center section, add the tip (some big gaps because of it’s angle appear but the instructions say don’t worry about them so we didn’t.). Glue in the forward spars and remove it from the board your ready for the other half. It tool longer to help Westlee read the instructions than for us to build the wing half. I think he had as much fun learning to read the big words and checking off the instructions as he did building. The leading edge sheeting on the bottom is not completed until the wing halves are joined. Before joining the wing halves we decided to make them bolt on so we added some half ribs next to the root rib from 3/8″ balsa, This made the root rib a full 1/2″ thick for each half from the spar to the leading edge. This 1″ of balsa laminate was used to hold the wing dowel. The wing panels were joined per the instructions and after Westlee went to bed Dad added the aileron torque rods and a piece of 1/16″ plywood over the trailing edge to anchor the trailing edge blocks and make a stronger attachment for the 1/4″ hold down screws. The center section is reinforced with a 1″ piece of fiberglass tape CA’d per the instructions. The ailerons are pre-shaped and only needed to be trimmed to length and have a hole drilled to accept the torque rods. Everything was sanded and ready for covering.

The fuselage was next, because that is the order it was in the plans and Westlee would not let me do anything out of order. The fuselage is built from 1/8″ balsa. There are 4 pieces of plywood in the fuselage; the firewall, landing gear block, tail wheel support and F-2D ply former that goes to the top of F2. This is where the wing dowel will go. Although the LT-25 is designed for rubber band attachment of the wing, all that was necessary to add to make the wing bolt on was two 1/4″ plywood blocks glued where the trailing edge meets the fuselage to accept 1/4″ nylon bolts. The people at Sig did a great job as the LT-25 was obviously designed with this modification in mind. I prepared the firewall and motor mounts per the instructions then glued in the firewall and second former. The next day we assembled the fuselage like a jigsaw puzzle. After all the pieces were in place with a couple of rubber bands around them, the fuselage was completely assembled with no glue. All the laser cut fuselage pieces fit perfectly into their respective tabs. It is perfectly square and you cannot twist or flex it even without glue. Westlee decided we needed to glue it anyway, and proceeded to put drops of CA where dad pointed. It was time for bed so we glued in the landing gear block, put a weight on it and went to bed. The next session, I wanted to add some tri-stock to beef up the landing gear but since it was not in the plans, Westlee said we did not need it. After 25 or so flights, Westlee was right the landing gear have been rock solid, even with Westlee’s big brother’s landings. Spencer is 9 and did some of the LT-25’s test flights. After Westlee went to bed I installed the controls. The rudder and elevator use nylon rods. The formers of the fuselage have a front and back and if you put them in wrong the rods have a snake like appearance which does not affect how they work. The instructions are very good and make it very clear on how to put the formers in so that the control rods are strait but I did after all let a 7 year old do most of the building. The tail wheel uses a pull-pull system that is very easy to install and setup, especially when your 7 year old is in bed.

Building the tail feathers is absurdly simple. You do have to cut some 3/8 square balsa sticks but the way they are notched into the laser cut perimeter pieces even if they are 1/16″ short they will still work. Westlee cut all his right on the money. I only needed to get two extra 3/8″ sticks from the hobby shop. Westlee likes using the razor saw so did not mind having to re-make several pieces just so he could “practice”.

Everything was sanded, the leading edges of tail feather rounded off and the rudder and elevator punched out. The firewall and engine compartment were painted with black fuel proof dope. I covered the entire model with transparent red Monokote and put on the window stickers from the LT-25 Kit and some unused stickers from a Four Star 40. We then glued on the tail feathers and attached the control rods. Radio, fuel tank, and engine installation are straight forward. Just follow the instructions and you cannot go wrong.

The finished product looked very good and performed way better than I expected. I used an old OS-25SF for power and a full 8 ounce fuel tank. The model balanced on the spar with just a slight movement of the battery. Westlee’s Kadet LT-25 when complete weighed just under 4 pounds. And the all transparent plane attracted a lot of attention at the field.

The first flight was uneventful and dull. I was unimpressed with the takeoff as it took almost 200 feet to get in the air. Once airborne it performed very well. It needed about 4 clicks of down elevator to fly strait and level at 1/2 throttle. I overshot the first landing. The Kadet was at a high idle about 10 feet in the air over the end of the runway and was still 3 feet in the air at the far end 400 feet away. I went around and decreased the throttle trim. The next approach was dead stick as I killed the engine I was 20 feet in the air and circled the field before landing. The Kadet LT-25’s 12 ounce wing loading makes it float and fly slower than any plane I have ever seen. First post-flight inspection showed that the tail wheel would not turn and both main wheels were rubbing on there wheel collars. I loosened the wheel collars and the next flight takeoff distance was a much more respectable 5 feet instead of 200. It is amazing what happens when you turn off the brakes. The second flight included big loops, tight little loops, rolls, split-s, cuban-8’s rolling circles (sloppy), tail slides, stall turns, tail wheel only touch and goes, and some other un-named stuff all at 1/2 throttle or less. At full throttle the response is crisp and it can climb in knife edge flight. Its top speed is comparable to most 40 size trainers. The Kadet will fly inverted but requires quite a bit of down elevator and is always trying to roll back over. If it were built with only a little dihedral it would be awesome. In a light breeze, zero air speed landings are easy. The 8 ounce tank allows for 30 minute flights. We hooked up the buddy box and let both sons fly it. Westlee enjoyed flying his new model for about 5 minutes, but had met a new friend and had to get back to the tire swing. Spencer, my 9 year old son, said if flew OK but snapped too slow, handled like a pig inverted and was hard to do outside loops. He prefers the Four Star on high rates.

In the first month of flying this plane I have used it training my sons, and about 1/2 dozen other students. The plane is amazing in the air. Iit does almost any maneuver you want. I have been unable to get a tumble but I am sure it would if I moved the CG back. You can move the throttle trim up and do horizontal 8’s at a fast idle and never get more than 5 feet off the runway or more than 40 feet away from you. Letting some of our clubs better pilots fly it and you have to take the controller away. I have let a dozen or so people fly it, the one thing in common weather just putting around the sky or twisting and gyrating is the smile. Everybody who flys the Kadet LT just cannot stop grinning.

Comparing the LT-25 to 40 size trainers, the LT-25 is miles ahead. The LT-25 flys circles around most 40 size trainers, including other Sig Kadets. It is lighter and more nimble. It is slower and more stable. It is less expensive to build and fly. You can putt around the sky at 1/4 throttle that is about 1/4 the cruising speed of most trainers. It lands slower than any 40 size trainer. It is only mildly self corrects and even at slow speed the controls are crisp and immediate. A plane that does not hesitate when control inputs are made and flys very slow is a great combination for training.

The Sig Kadet is by far the best model airplane kit I have ever experienced. The flying characteristics although tame are fun. It makes a great primary trainer and is surprisingly aerobatic. I am having as much fun with this plane as with my fun-fly and speed demons. I would recommend this as a first kit to newcomer. The instruction book is a virtual tutorial on how to build model airplanes. I would recommend it to old-timers if they want a model that builds better than any kit they have ever had and is a blast to fly.

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