On February 10, 1999, about 1755 eastern standard time, a Piper PA-34-200T, N39531, landed hard on runway 09, at the Sanford Airport, Sanford, Florida, while on a Title 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed at the time and an IFR flight plan was filed. The aircraft received substantial damage. The private-rated pilot and four passengers reported no injuries. The flight originated from Key West, Florida, at 1600. The pilot reported that he was too fast on the landing touchdown, causing the airplane to porpoise, and land hard. Some parts fell off the airplane. Airport operations personnel picked up a briefcase and flight bag from the runway. The pilot stated, "...a late flare and too much speed resulted in a ballooning of the airplane and subsequent porpoising resulting in the damage. The impact was not violent and did not seem to be hard enough to produce the resulting damage. I was able to taxi off the runway with no problem...only upon engine stoppage did I notice the prop."