Kestrel (oz3719)

About this Plan

Kestrel (aka Kestral). Single channel radio control sailplane. Here is Dave Robelen's Kestrel from Model Airplane News issue 09-68.

Quote: "This soaring glider is simple to build yet clean and neat. It's almost impossible to pass by without serious consideration. Designed for single channel, but mini-propo will fit. The Kestrel is a model sailplane born of compromise. I have read many times about the thrills of soaring, but had never witnessed any R/C glider thermal soaring firsthand. The area in which I live, typical of many East Coast flying sites, has a fairly strong breeze most of the time. When the midday thermals are present, the breeze is normally above 10 mph, sometimes as high as 20.

The first requirement, therefore, was a fast but flat glide with some ability to slow down when the winds would drop off. The Kestrel meets this requirement with a flat-bottomed, low-drag airfoil combined with a fairly light wing loading.

Other requirements were as follows: scale-like appearance, strong, simple construction, high strength for some occasional slope soaring, ability to fly well with the many excellent rudder-only systems currently available, and an ability to be launched via the high-start system.

After surveying the above requirements. I decided to design my own plane to meet them. The fact that I met with some success is the reason for this article. I wished to share the fun.

If complex structures are the reason some of you may have avoided gliders, please look at Kestrel closely. It can be built in no more than a week of lazy evenings, and for the novice, the Kestrel has fewer difficult alignment chores than most models. Just imagine, no engine or mounts, landing gears, or even fuel tanks and plumbing, and the wings and tail are very simple to construct without warps or misalignments.

The novice will also find Kestrel very easy to fly and quite resistant to damage. As for the expert, the challenge is always there with a thermal riding glider. No two days are exactly alike and there is never the monotony of stunt flying. It probably will give your adrenalin glands quite a rest too. In fact, sometimes I find it difficult to enjoy a power model after watching Kestrel riding a thermal hundreds of feet high.

The Kestrel won't break your piggy-bank for equipment either. A single channel outfit is completely adequate. There are many on the market now and I don't want to promote any one line, but the radio system sold for the Testers Skyhawk has many good features.

The original Kestrel is equipped with an Adams actuator, a Citizenship RSH superhct, an Ace add on switcher, and three 500 mah pencell size nickle-cadmium cells..."

Direct submission to Outerzone.

Update 20/02/2017: Replaced this plan with a clearer copy, thanks to theshadow.

Scan from DBHL, cleanup by theshadow.

ref DBHL-516721.

Direct submission to Outerzone.

Supplementary file notes

Aticle pages, thanks to RalphB.
Previous scan version.

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