On November 2, 2004, at 1130 eastern standard time, a Cessna 120, N1811N, was substantially damaged during a ground loop and nose over at the Windham Airport (IJD), Willimantic, Connecticut. The certificated flight instructor and the certificated commercial pilot, who was rated only in helicopters, were not injured. Visual meteorological conditions prevailed for the local instructional flight that originated at Windham Airport, at 1055. No flight plan was filed for the flight conducted under 14 CFR Part 91. The instructor provided both a written statement and a telephone interview. He explained that his student was a commercial helicopter pilot with only 8 hours of experience in airplanes; all of which was in the accident airplane. The instructor had the pilot practice braking and turning on runway 27. After the pilot taxied for some distance, the instructor asked him to "head back." At the time, the airplane was traveling about 15 miles per hour. The pilot initiated an immediate right turn to reverse direction that oriented the tail into the wind. The tail rose up in the turn and the airplane continued around and over onto its nose. The instructor said he expected the pilot to slow the airplane prior to the turn. Instead, the application of brakes was "aggressive" and "uneven", and the airplane ground-looped to the right and continued directly into the nose over. During a telephone interview, the pilot concurred with the instructor's version of events. He said that he intended to slow the airplane before the turn, but that his braking was "uneven", and resulted in a "hard" right turn and the nose over. Both pilots reported there were no mechanical deficiencies with the airplane. The instructor reported 1,379 hours of flight experience, 75 hours of which were in the Cessna 120. The pilot held a commercial pilot certificate, with ratings for rotorcraft helicopter and instrument helicopter. He reported 6,500 hours of experience in helicopters, and 8 hours in airplanes; all of which was in the accident airplane. The weather reported at Windham Airport, at 1052, included an overcast ceiling at 5,500 feet and wind from 180 degrees at 3 knots. The instructor reported that, at the time of the accident, the wind was from the southwest about 8 knots.