On December 3, 1994, about 1730 eastern standard time, a Sikorsky UH-60A, serial number 23321, registered to U.S. Army Aviation Command, operated by the U.S. Customs Service, on a public-use positioning flight, collided with a hangar while ground taxiing into a parking area at the St. Petersburg-Clearwater International Airport, St. Petersburg, Florida. The helicopter sustained substantial damage. The airline transport-rated pilot, commercial pilot, copilot, air interdiction officer, and two occupants were not injured. Visual meteorological conditions prevailed and an agency flight plan was filed. The flight originated from Jacksonville Naval Air Station, Jacksonville, Florida, about 1 hour before the accident. The airline transport-rated pilot-in-command (PIC), and copilot stated after landing they taxied to the U.S. Customs ramp where they were met by maintenance personnel. The PIC was asked to park in a grassy area. They informed the maintenance employee that they had night vision goggles and weapons on board the helicopter, and needed to park in a secure area between the two hangers. No request was made by the PIC, nor was he asked by maintenance personnel if he wanted marshalling support while taxiing the helicopter. He taxied into the unmarked parking area along the northwest corner of the ramp, made a right turn towards the south, and continued towards the southeast corner of the ramp. As they started the final right turn, a crewmember stated, "we are getting close," and the main rotor blades collided with the hanger. Information pertaining to aircraft information is contained in NTSB Form 6120.1/2 and NTSB Form 6120.4. Toxicology studies of specimens from the pilot-in-command, and copilot were negative for neutral, acidic, and basic drugs. Review of written procedures at the Jacksonville Air Branch, Tampa Air Unit, SERV-AIR Inc., Standard Operating Procedures, and the Aviation Operations Handbook for U.S. Customs, revealed there are no written procedures concerning designated parking areas, marking of parking areas, and marshalling of aircraft.