This is preliminary information, subject to change, and may contain errors.
Any errors in this report will be corrected when the final report has been completed.

On May 12, 2003, about 1206 mountain standard time, a Hughes OH 6A, N6636H, collided with terrain near Pan Tak, Arizona. The helicopter was owned and operated by U.S. Border Patrol as a public-use aircraft under the provisions of 14 CFR Part 91. The commercial pilot sustained minor injuries. The second commercial pilot/observer sustained serious injuries; the helicopter was destroyed. The cross-country flight departed Ajo, Arizona, about 1130, en route to Tucson, Arizona. Day visual meteorological conditions prevailed, and no flight plan had been filed. The primary wreckage was at 32 degrees 02 minutes north latitude and 111 degrees 31 minutes west longitude.

The pilot reported that while flying about 300 feet above ground level (agl) he heard a loud bang followed by the helicopter becoming uncontrollable. The helicopter came to rest on mostly level desert terrain. Most of the major components to the helicopter were located in the area of the main wreckage. The tail rotor gearbox and tail rotor blade assembly were missing from its attachment point of the tail boom. A search of the area for the tail rotor assembly or other related pieces of the helicopter was negative.

During the search for the missing components, searchers found a U.S. Border Patrol flight jacket. The jacket was located approximately 0.7 miles west of the accident site. Examination of the flight jacket revealed that the jacket had been shredded. The jacket also had red and white colored paint transfers. The tail rotor blades on the accident helicopter reportedly were painted with red and white colored paint.