On March 16, 2004, at 1400 central standard time, a Piper PA-30 twin-engine airplane, N572AS, registered to and operated by Aerial Survey, Inc., of Galveston, Texas, was substantially damaged following a loss of directional control while landing at the Scholes International Airport (GLS), near Galveston, Texas. The commercial pilot and pilot-rated passenger were not injured. Visual meteorological conditions prevailed and a company visual flight rules (VFR) flight plan was filed for the Title 14 Code of Federal Regulations Part 91 personal flight. The local flight originated at 0945. The 580-hour pilot reported in the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) that the final approach was "normal." As the aircraft touched down on Runway 31, the main landing gear hit first, followed by the nose landing gear. After the nose wheel touched-down, the airplane immediately began to feel "squirrelly," and the inputs to the rudder "seemed" to be ineffective. The pilot stated that the brakes "locked up." The aircraft slid for approximately 350 feet and veered off the right side of the runway into an embankment. In a separate statement provided by the operator, the pilot-rated passenger stated that the pilot purchased a block of time from the operator to gain flight experience as a pilot in command of a twin-engine airplane and that he accompanied the pilot-in-command (PIC) as an observer. He reported that the PIC was the sole manipulator of the controls. The pattern entry was "normal," the downwind leg was "normal," and the pre-landing checks were completed. On the base leg, the PIC called for flaps and 10 degrees of flaps were deployed and visually verified. The final leg was "normal," and approach speed "appeared" to be correct, along with the alignment to the runway. Runway touchdown was "normal." During the rollout, the PIC lost directional control and applied "heavy" brake pressure, locking them up. As the airplane exited the runway, the pilot-rated passenger ensured that the throttles were closed. The airplane came to rest after skidding off the runway and into the grass. Runway 31 was 6,000 feet long by 150 feet wide. The runway surface was reported to be in fair condition, with the first 1,300 feet of the runway concrete, and the remaining runway surface asphalt. The reported winds at GLS at the time of the accident were from 130 degrees at 7 knots. Examination of the aircraft by a FAA airworthiness inspector, who responded to the accident site, revealed structural damage to the right wing spar, and the right main landing gear was collapsed. Flight control continuity was established and no anomalies were found.