On April 17, 2004, about 1230 eastern daylight time, a Cessna 172S, N5280D, registered to I72 Inc., and operated by a private individual as a Title 14 CFR Part 91 personal flight, veered during landing in Key West, Florida. Visual meteorological conditions prevailed, and no flight plan was filed. The private-rated pilot and 4 passengers were not injured, and the airplane incurred substantial damage. The flight originated in Fort Lauderdale, Florida, the same day, about 1125. The pilot stated that during the final approach to land he did not experience any turbulence, but he noticed that the indicated airspeed was fluctuating between 75 and 80 knots. Once over the touchdown area, he said that he experienced strong gusts which caused a hard landing, and as the right main landing gear touched the runway during the hard landing the airplane bounced back in the air a few feet. He said the nose of the airplane was still over the centerline of the runway, so he reduced power and allowed the airplane to glide to a touchdown, but as the airplane touched the runway, it immediately skidded to the left, and the right main landing gear impacted one of the fixed distance signs. Prior to the accident the pilot stated there were mechanical failures or malfunction to the airplane or any of its systems.