On November 4, 2004, about 0900 eastern standard time, a Robinson R-22, N7188N, registered to Brentone LTD and operated by Lunsford Air Inc, as a Title 14 CFR Part 91 instructional flight, had substantial damage discovered during a preflight inspection at Spruce Creek Airport, Daytona Beach, Florida. Visual meteorological conditions prevailed and no flight plan was filed. The flight was originating at the time of the accident. During a preflight inspection, damage was discovered to the tailcone assembly of the helicopter. Upon further examination and consulting with the manufacturer of the helicopter by the operator, it was determined that a major repair was required to return the helicopter to airworthiness condition. The forward bulkhead, forward bulkhead skin, and doublers for that area of the tailcone had to be replaced. The questionnaire submitted to the manufacturer by the operator to aid in assessing the type of repair required stated, "damage was sustained during a hovering autorotation." On December 3, 2004, an inspector from the FAA notified the NTSB of the damage. On December 8, 2004 a completed Pilot/Operator Aircraft Accident Report was provided by the instructor pilot, who flew the helicopter the day before the damage was discovered. He stated he had not seen the damage and does not know when or how it occurred. He only assumes the cause was from a hard set down during a practice hovering autorotation.