Sig Kadet LT-25 Conversion to Electric

Review Donald D. Runnells size 63-inch span, 51 inches long.  4 lbs., 15 ounces ready to fly, including battery pack.  Wing area is 725 square inches, for a loading of 15.7 ounces per square foot.
Motor Model Electronics (MEC) Turbo 10 Plus motor Servos 3 Futaba S3004 standard-size servos and a standard-size Futaba 7-channel FP-R127DF receiver
Speed Controller MEC 80X Electronic Speed Controller/Battery Eliminator Circuit + MEC ESC/BEC throttle controller. Batteries MEC solderless 10-cell 3000 mAH Panasonic
Channels 3 + Motor Flight Time Maximum flight times of 12 to 14 minutes with throttle management.  Generally about 10 minutes.
Propeller 12/8 prop, either an APC nylon electric or a Master Airscrew wood electric. Gear Box MEC gear box, 6:1 ratio
Pictures Follow the link for Pictures Video  

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Wingspan   Length   Weight  
Wing Area   Wing load   CG location
from wing edge		  

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Building Designed for 0.25 to 0.35 glow engine.  I built it almost stock, straight out of the box.  No significant modifications except to use an electric motor instead of glow.  Covered in Monocote.  It is the first plane that I have built from a kit.
Minor modifications: Added one layer of 1/8-inch balsa to front third of the fuselage floor to help support weight of battery in location of fuel tank and to strengthen the landing-gear area.
I drilled three half-inch holes through the firewall for cooling to the battery, and two air scoops added behind firewall for additional cooling.  (Air scoops were made by cutting the bowls of plastic spoons in half.)  A hole (about 1.5 inches by 2 inches) was also cut in the top of the fuselage just behind the wing to allow warm air to exit during flight.
Battery lies on the fuselage floor in location of fuel tank.  Two small blocks of foam used to level the battery and center it in the former. Battery is inserted through the existing hatch behind the firewall. Battery is held in place by a small strip of Velcro on the supporting block of foam.
Motor is mounted using kit-supplied nylon mounts.  I beveled the edges of the support arms and added Velco strips to seat the motor.  A plastic strap and a strip of electrical tape hold the motor tight to the mounts.
Batteries are arranged side-by-side in one layer, to produce a long, narrow pack.
The CG balance came out perfectly with the front end of the battery situated about 2 inches behind the firewall.  No other weight adjustments were necessary.
Bench runs show 32 amps and 350 watts at full throttle, about 5500 rpm. Other motor/battery systems of similar power would certainly work just as well, but appropriate gearing and a large prop are essential.
Take-off Flying from a field at 5400 feet elevation in Colorado.  On a freshly charged battery the plane takes off in less than 50 feet.  Tail-dragger configuration allows good ground control during take-offs and smooth landings.
Flight behavior Does inside loops from level flight --- as many in succession as you wish. Barrel rolls and inverted flying are easy.  Can get 10 to 15 touch-and-go landings per battery charge.
Landing Lands gently and easily with the motor running slightly above idle. Dead-stick landings have been a bit hard. Stalls are rare, soft, and predictable.
Crash Results No crashes yet.  I have been flying park flyers and an ARF sport plane for about a year and find this airplane very easy to fly.
Repairing  
Other comments All in all, a great flying airplane.  Easy to build from the kit and an amazement and source of many compliments from pilots who have never flown an electric.
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