The Edmonds Deltie is one of the most popular boost gliders, and with good reason. The glider is well designed, and it has a nice style to it. It can be assembled and ready to fly in a very short period of time. Considering the fact that the glider only weighs around five grams, it is capable of staying in the air for a long time.

Construction

When you finish putting the glider together, I recommend using some very fine sandpaper in order to sand the balsa wood smooth and to round the edges of all parts. This will make it more aerodynamic. Again, remember that this is fragile balsa wood. Handle it carefully.

The glider is boosted into the air with a motor pod that is 13 mm in diameter. The parts for this pod are supplied in the kit. The only flaw of this kit was found here. There was no motor block for the pod. However, this problem is easily fixed since 13 mm motor blocks are available from Estes or Apogee Components.

The pod has a small streamer attached to a Kevlar® shock cord as its recovery system. When working with it, I recommend installing it and preparing it according to the instructions. Many people tend to add a longer shock cord or a longer streamer. If you do that, you may encounter a pod/separation failure in flight known as a "Red Baron." The glider gets tangled in the recovery device of the pod, and the two fall to the ground together. This may or may not damage the glider, but in competition, a Red Baron is an automatic flight disqualification (I speak from experience) whether it is damaged or not.

Flight

Before you launch your glider into the air, you will need to trim it. The instructions have you mark where the center of gravity should be located on the glider when it is completely built. Use the trimming clay supplied to add any mass at the front or the back of the glider in order to get the glider to balance at the mark that you made before you built the glider. Test fly it by throwing it with your hand several times until the glider flies straight. You will also want to add mass with the clay to one side of the glider so that it will turn in circles when glides down. Otherwise, the glider will fly straight from a high altitude and you will not get it back, no matter how far you go to chase it.

When you load the glider with the pod attached onto the pad, you will need to clip a cloths pin onto the launch rod so that the pod can rest on it. Then hook the glider onto it so that it fits loosely, but securely rests on the hook of the pod. Another cause of Red Barons is the glider hooking onto the pod too tightly, so check this before you go up.

The pod will take any 13 mm motor. However, I would not recommend using an Estes A10 or an Apogee B7. Those two motors have too much thrust, and would probably shred the glider. The Apogee A2 and B2 10.5 mm motors are great for this glider. They allow a long burn which provides lower amounts of thrust and a smooth boost to a higher altitude. Depending on how well you trimmed the glider, it should stay up for a long time. It's a good idea to have two people recover this thing, with one person watching the pod and the other watching the glider.

Grades

Design: A+
Construction: A+
Flight: A+

A fun to build and fly glider with perfect A+ ratings. Don't let this kit ever pass you by.