EAA 732 The Northwest Arkansas Chapter

Jim Younkin is known by many for his creation of the air racing replicas, the Travelair Mystery Ship, and Mr. Mulligan, as well as the super Stearman "Goliath", the Mystery Pacer, and more recently the Mullicoupes. He is also known for his G Model Staggerwing production line which saw three D models converted to G Models and then upgraded with a number of engineering improvements. Finally, he is also known by some for his activity in the art of forming compound aluminum aircraft parts. All these activities were accomplished in his retirement years. Prior to these, his professional career as an electronic engineer was in the field of designing gyro instruments and autopilots for general aviation. In the late 1950's he developed the first miniaturized solid-state gyro slaving system which he sold to AIM (Aviation Instrument Mfg Co.) From AIM, Mr. Younkin went to Mitchell Industries where he designed autopilots and related instrumentation. During that period he invented the low-friction heading selector (bug) into the three-inch vertical card DG. This basic design concept is used today in all autopilot directional gyros. Mr. Younkin's primary accomplishment at Mitchell was autopilot design, and Jim was the sole designer of the Century III, the first attitude position autopilot to fly without feedback sensors on the servos. Mr. Younkin also developed the Century I and Century IV, and contributed to the design of the Century Forty-one, which evolved into the present-day Century 2000. Another product, the NSD-360 horizontal situation indicator (HSI) is Mr. Younkin's design. This unit is probably in greater use today than any other HSI, and it is still being produced. As could be expected, Mr. Younkin holds numerous autopilot patents. Jim spends his time now developing and marketing solid-state digital autopilots for the experimental aircraft market.