On February 21, 1999, about 1825 Eastern Standard Time, a Signature Flight Support employee was fatally injured when he came in contact with the rotating propeller of N3559U, a Piper PA-32R-301. The airplane was parked on the ramp area of Signature Flight Support at the Washington Dulles International Airport (IAD), Dulles, Virginia. The certificated airline transport pilot and four passengers were not injured. Visual meteorological conditions prevailed, and no flight plan was filed, for the personal flight conducted under 14 CFR part 91. The pilot stated that he performed a preflight examination of the airplane. He removed the chocks around the main wheel, and removed the chock in front of the nose wheel, by placing it in an "L" position. While the airplane was parked, with the engine operating, the pilot was transcribing the Automated Terminal Information Service (ATIS). He looked out the windscreen and noticed a Signature Flight Support employee approaching the airplane. As the employee walked closer to the airplane, the pilot thought that the he was too close to the propeller, so the pilot raised his arms in an attempt to signal the employee to stop. The employee walked into the propeller. The front seat passenger stated "...The pilot was waving off the flagman as he walked toward the nose of the plane. The pilot began shutting down the engine as he was stating something about the flagman getting too close to the prop." The passenger further stated that the Signature Flight Support employee bent down in front of the propeller, with one arm extended forward, focused on the nose wheel area of the airplane. The propeller struck the employee in the head. The employee was not accompanied by any other Signature Flight Support employees. A witness stated that he arrived at the airport approximately 10 minutes before the accident. He was watching arriving and departing airplanes, from his automobile, behind a security fence. The witness stated that the airplane was parked with the engine running for approximately 3-4 minutes. He observed a Signature Flight Support employee approach the airplane and lean into the propeller. The witness further stated that the employee seemed to be fixated on the front landing gear. He did not observe any other Signature Flight Support employees near the airplane before, or during the accident. A co-worker stated that he discussed the "marshalling" of the airplane with the employee. The employee said to the co-worker that chocks were not a factor as they were already removed from the main tires, and the chock around the front tire was in an "L" position. The employee started walking toward the airplane, and the co-worker walked back to his duty station. Later, the co-worker heard screaming, approximately 100 yards away from his position, but he did not witness the accident. Several co-workers reported that the employee was "not himself" the day of the accident. He seemed distant, smoked more cigarettes than usual, and had to have his name announced several times before he became attentive. The co-workers stated that he may have been distracted by several domestic issues. According to a Federal Aviation Administration (FAA) Inspector, the employee had worked at Signature Flight Support for approximately 3 weeks. He had no prior aviation experience. The toxicological testing report from the FAA Toxicology Accident Research Laboratory, Oklahoma City, Oklahoma, was negative for drugs and alcohol for the employee. An investigator from the Virginia Occupational Safety and Health Administration stated he was familiar with Signature Flight Support's operation. He had investigated the facility approximately 18 months earlier, and found that Signature Flight Support had an excellent training program. The training program consisted of 7 modules. This employee had completed module # 1, and was studying module # 2, which included the handling of propeller aircraft. Investigation by the Metropolitan Washington Airports Authority Police Department revealed that the ramp area was clean, dry, and clear of any debris. Visibility was "excellent," and "No unsafe conditions were noted at the accident scene." A review of Signature Flight Support's training module # 2 revealed that propeller safety is addressed in the text material.