On June 18, 1995, about 1545 mountain daylight time, N1967M, a Boeing A75N1 Stearman, operated by the owner/pilot, groundlooped on landing and was substantially damaged in Helena, Montana. The airline transport pilot and the private pilot were not injured. Visual meteorological conditions prevailed and no flight plan had been filed. The local flight was conducted under 14 CFR 91. According to an FAA aviation safety inspector from Helena, and statements provided by both pilots, the owner of the airplane (a rated private pilot) was receiving a flight familiarization by the airline transport pilot. The airline transport pilot was not instructor rated. The pilots were conducting touch-and-go landings on runway 27 at the Helena Regional Airport. The airline transport pilot stated that the aircraft, with the private pilot at the controls, flared and touched down left gear first in a crosswind, then veered sharply to the left. According to the airline transport pilot: "Realizing the owner was not correcting quickly and appropriately enough, I took full control, applied full right aileron and right rudder with maximum available braking." The aircraft continued veering left as the tailwheel lock disengaged. The lower right wing and aileron then contacted the runway. No preimpact mechanical malfunctions were reported, and gusting wind conditions prevailed. The private pilot stated that both pilots applied opposite aileron and brake at the time of the groundloop.