On September 18, 1999, about 1200 Eastern Daylight Time, a Cessna 305A, N86WM, was substantially damaged during a banner pickup at Skylark Airport (7B6), Warehouse Point, Connecticut. The certificated commercial pilot was uninjured, and visual meteorological conditions prevailed at the time of the accident. No flight plan was filed for the local banner-towing flight, conducted under 14 CFR Part 91. According to the pilot, the banner became hooked on the airplane's right main landing gear during the pickup. The airplane became difficult to control, so the pilot opted to land it on the grass, about 20 degrees to the left of Runway 28. After touchdown, the banner and the wet grass caused the airplane to rapidly decelerate, and as it did so, it slowly nosed over on its back, just before coming to a complete stop. About 9 minutes before the accident, winds were recorded at an airport 5 nautical miles to the west, as being from 340 degrees magnetic, at 9 knots.