Folkerts SK-3 Peanut

The Air Racers of the 1930s are perhaps my favorite aircraft type of all time. I'm drawn to many of the aircraft of this period, but some of the most appealing are the slim machines designed by Clayton Folkerts. While searching for free flight plans of the SK series I discovered the Peanut SK-3 designed by Kurt Enkenhus and published in the January 1978 issue of Model Builder. Unfortunately the full-sized plan had been suspended from the great resource that is Outerzone, so I looked elsewhere, but in vain. I then was able to find a copy of the magazine but the plan was not full size, nearer to 50% at 6.5" wingspan.

The article attached to the plan is remarkable. It contains Kurt's performance calculations based on weight, available power, drag and propeller efficiency. The completed model performed essentially identically to the prediction.

A work colleague (thanks Michael!) happened to know that the collection of Model Builder/Bill Northrop plans were now in the hands of the Academy of Model Aeronautics. An email to them resulted in a print being made available for a moderate number of shekels. Great service from Greg Prater at the AMA and a happy end to the day.

I doubt I will build this as a Peanut. My intention is to enlarge it somewhat, perhaps as much as 400%. I'll figure that out later. In the meantime I have the Ralph Kuenz SK-2 plan, and the SK-4 short kit coming from Volare.