The 2 meter concept was introduced in the mid 90s as another way of setting aircraft and engine requirements. Prior to that there was a limitation on engine displacements - .61 cu in 2 strokes or 1.20 cu in 4 strokes. The factor of 2 difference was because in the beginning of 4 stroke development these two sizes were about equal in power output. But as the 4 strokes developed it became clear that some other method of limiting the models would be needed. The 2 meter concept was the answer - limit the size and weight of the airframe and remove any limitation on the engine. The limits were 2 meters or less in wingspan, 2 meters or less in fuselage length and a weight of 11 lb (actually 5 kg) or less. This resulted in larger airframes (obviously) and the use of carbon fiber, kevlar, titanium hardware, etc in order to keep the weight down. Engine technology (and cost) went up dramatically. This is an interesting example of designs evolving to meet new rules - something that is standard in most any type of competition.

By this time the use of the box and turnaround pattern had become standard and airspeeds were reduced compared to the ballistic days. The speed advantage of retracts was gone. More emphasis was placed on vertical performance and snap roll maneuvers were introduced. Greater side are was needed to optimize performance. As the patterns became more complex you watch the evolution of the designs over the past 15 years or so. The early turnaround planes were recognizable extensions of models from the 80s, but today's models have evolved to the point that there is little resemblance to the style of plane flown then.

The evolution of pattern designs makes sense when viewed in the context of the rules that existed at any given time period. Unfortunately, the evolution has resulted in increased size and cost. I still enjoy flying the classic pattern planes and can fit them into my car and also my Cessna Skylane for longer trips. I would be hard pressed to fit my Hydeout in the Cessna!

Jeff