In the air, tundra tires clearly had an adverse effect, reducing the aircraft's top speed, rate of climb, angle of climb, range, useful load and stall warning (buffet) margin. Data from the tests did not, however, validate the theory that oversize tires raised the PA-18's stall speed. In fact, stall characteristics were found to be normal in level flight and in a turning stall, as the airplane generally rolled to a wings-level attitude. But in maneuvering flight, the nose tends to drop as bank angle is increased. If the pilot uses "top rudder" to counter this effect and stalls the aircraft while cross-controlled in this manner, the airplane tends to roll rapidly over the top and enter an incipient spin.