Firebaby Twin & Super Stunter

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These two very special Firebabys are from Frank Macy's collection. Frank shares some backround information on these one-of-a-kind models and their respective builders.

Firebaby Twin
by Johnny Knepper

Twin engine Firebaby used Anderson Baby Spitfire engines

Johnny Knepper was one of those innovative multi-talented modelers that often developed ideas or products for American Junior Aircraft.

He was also one of those terrific tinkerers that was responsible for the development of the Firebaby.

Besides being an exquisite model builder, Johnny was a Tool & Die Maker, and accomplished Machinist who could perform a symphony on a Lathe.

Jojnny Knepper with his 1910 Wakefield rubber powered plane
Johnny Knepper with his 1910 Wakefield

Shortly after they produced the Firebaby, Johnny got the idea of making it a twin engine job for racing. Not for production, but to satisfy his own curiosity and that of his son, who had volunteered to be the pilot in this daring venture. At the time, the North American F-82 Twin Mustang was still in service, and basically that's where he got the idea.

They powered the Twin Firebaby with Anderson Baby Spitfire engines of .045 cu. inch displacement and won many races with it. Several others in the the Portland area also built the Twin Firebaby, but the famous Knepper Team had to show them how to do it.

Johnny Knepper passed away in June, 2004.

Twin engines of the special firebaby by Johnny Knepper


Firebaby Super Stunter
by Billy McDow

Firebaby Super Stunt U-Control by Billy McDow

Sometime in the mid-fifties Billy McDow mentioned to Jim Walker that he was going to make a Super Stunter out of the Firebaby. Bill was one of the better model builders in the neighborhood and test flew many planes for Jim.

The first thing he did was to discard the standard wing. He then built an entirely new wing with ribs in a symmetrical airfoil section. It was unique in that he used 1/16 inch balsa sheet for the base, upon which the longitudinal half ribs were glued to make the symmetrical wing. The wing was then covered with colored tissue, top and bottom, then clear doped and fuel proofed. In addition, the elevator area was enlarged by 100%
(notice extension of the trailing edge of the elevator in photo). Mounting a new
Cox .049 engine up front, it became a hot 1/2A stunt machine.

Although Jim was impressed with its performance, and he admired Bill's talent, it was never to be a production item. Bill McDow later donated the Firebaby Super Stunter to Frank Macy's American Junior Collection.

Symetrical wing of the Firebaby Super Stunt U-Control plane by Billy McDow

Wing plan for the Firebaby Super Stunt - Billy McDow original drawing

Billy McDow's original wing plan for the Firebaby Super Stunter.


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