On April 15, 2000, about 1800 eastern daylight time, a New Standard D-25, N930V, registered to a private owner, and operated as Title 14 CFR Part 91 commercial sightseeing flight, lost control during the landing rollout at Lakeland, Florida. Visual meteorological conditions prevailed at the time, and no flight plan was filed. The airplane received substantial damage, and the airline transport-rated pilot and five passengers were not injured. The flight originated the same day, about 1750. The pilot was giving airplane rides at Sun n' Fun, and stated that he purposely landed long to give a helicopter which was on a taxiway, 100 yards from the approach end of the grass strip, plenty of room to maneuver. The pilot further stated that he landed with a tail wind, and did not slow the airplane down quickly enough, so upon applying the brakes, the airplane skidded on the wet grass, exited the runway and traversed a small berm, during which the left wing sustained damage. On May 3, 2000, an FAA inspector contacted the NTSB, stating that the pilot just reported the accident to him. The FAA inspector further stated that the airplane was not available, since the pilot had organized his own post accident examination and recovery of the accident airplane. The inspector said that the pilot had determined that the lower left wing spar had broken, recovered the airplane, and removed the wing, shipping it to a repair facility in Kentucky. A mechanic at the repair facility stated that the accident airplane's front wooden wing spar was cracked at the end strut attach point to the lower left wing, in the vicinity of the steel fitting.