HISTORY OF FLIGHT: On November 10, 1993, at 1740 central standard time, a Piper PA- 24-250, N6651P, was destroyed near Longview, Texas, during an uncontrolled descent. The commercial pilot received fatal injuries. Visual meteorological conditions prevailed for the flight. Investigation and interviews conducted by the investigator-in- charge and the Federal Aviation Administration (FAA) inspector revealed the following information. Fuel receipts indicated that the pilot purchased nine gallons of fuel that morning and made several flights for a total of one hour in the vicinity of the Gregg County Airport, Longview, Texas. The fixed base operator records established that other airplanes had flown throughout the day after being fueled from the same source. The airplane was observed flying "no more than 150 feet to 200 feet above the ground." Witnesses were aware that the airplane was based at the airport and had observed the airplane flying several times that day and numerous times in the past. They did not recall having seen the airplane flying "continuously low in the vicinity of the airport." One witness said the airplane landed at Rusk County Airport (17 miles south of Gregg County Airport) at approximately 1100 and taxied into the grass in order to pass around an airplane with a student and his flight instructor. The flight instructor reported to the inspector that "he felt the taxi procedure was impulsive and not required." Investigation indicated the airplane departed Gregg County Airport runway 17 from intersection hotel at 1739. Witnesses observed the airplane in a right descending turn as the pilot radioed a distress call just prior to impacting the trees and terrain. One witness stated that the airplane "did not appear to stall" that "vertical descent rate was minimal" and that he would "guess that wings level, the airplane might have been able to maintain altitude." He further stated he believed "this lead to panic on the part of the pilot." However, he reported when he saw the airplane "a power off landing could be made on either of two roads, each with 45 degrees turn." Witnesses reported that they "did not hear any cut out in the engine power." During telephone interviews, relatives and friends reported they had flown with the pilot numerous times in this airplane. On several occasions they recalled emergency situations where the pilot remained calm and handled the difficulties. They also described several flights where the pilot had flown low to take pictures of his business; however, they said he never flew the airplane low in the vicinity of the airport. PERSONNEL INFORMATION: The Federal Aviation Administration (FAA) medical records application dated August 19, 1992, for the issuance of a second class medical certificate indicated a total flight time of 2,400 hours with 200 hours during the previous six months. On the medical application the pilot checked "NO" for mental disorder of depression or anxiety, "NO" for alcohol dependence or abuse, and "NO" for a history of convictions. Counseling documentation reported that the pilot "has not had the guts to follow through. I can't kill myself." Personal records indicated the pilot was currently enrolled in a substance abuse and alcohol program at Sabine Valley Center, Longview, Texas. The staff (enclosed records) at the center diagnosed him as suicidal which was alcohol related. Staff and associates indicated the pilot was also having ongoing physical difficulties in that he was experiencing shakes and tremors. Records indicate the pilot had joined Alcoholic Anonymous (AA). Historical medical records (copies enclosed) indicated a medical diagnosis of personality disorders. The pilot attended some crisis resolution counseling sessions. Records indicated a family history of depression and medication for depression had been prescribed for the pilot. A background review supported by interview documentation revealed that the pilot's personal life was also becoming a strain for him. He was faced with bankruptcy, "three failed marriages and affairs on impulse while in committed relationships," repossession of personal property, and continued criminal probation. COMMUNICATIONS: A review of the air traffic control tower data revealed the following information. Official sunset was 1742. Local officials reported that it was dark at 1800. Flight data strips (copies enclosed) indicated the airplane departed and landed at Gregg County Airport, Longview, Texas, several times on November 10, 1993. Air traffic control tower recordings (transcript enclosed) for the last departure indicated the pilot was "going to make some local passes around and take a look at the night sky get current again." The pilot said he would be below two thousand feet. The pilot was assigned a transponder squawk and the airplane was cleared for departure on runway 17 from the "hotel" intersection. At 1739:24 the controller heard the transmission "I'm losing it, I'm losing it, hea help me help me." WRECKAGE AND IMPACT INFORMATION: Located approximately 1,000 yards beyond and to the southwest of the departure end of runway 17 were seventy feet high trees with numerous broken limbs. The wreckage distribution was a measured magnetic heading of 225 degrees for 175 feet. A portion of the right flap was found at the base of the initial tree line and the right aileron was lodged in the top of the tree. Seventy feet beyond another portion of the right flap and right wing pieces were found under numerous tree branches. The left wing was found on the ground 135 feet from the initial tree line. The fuselage came to rest inverted on a measured magnetic heading of 040 degrees against the base of trees. For additional details refer to the enclosed diagram. Leading edge crushed areas of the wings were equal in diameter to the trees. Fuel bladder tank integrity was compromised; however, there was a lack of physical evidence of fuel in the area. The integrity of the hydraulic system was compromised and physical evidence of the fluid was found on the tree leaves. Flight control continuity was verified by the control cables. Flight controls, indicators and trim tabs were destroyed. Propeller blades were bent and curved aft with striations and gouges at the tips. Numerous tree trunks and branches were found along the wreckage distribution path and a branch measuring 5 inches in diameter was found slashed. Wood was jammed into the propeller hub. MEDICAL AND PATHOLOGICAL INFORMATION: An autopsy was performed by The Southwest Institute of Forensic Sciences at Dallas, Texas. The Office of the Regional Flight Surgeon reports that "in Dr. Canfield's opinion, the combination of the levels of ethanol and marijuana may have caused impairment." TEST AND RESEARCH: An examination of the engine on November 12, 1993, indicated continuity and there were no discrepancies that would have contributed to a loss of power. The throttle control at the carburetor was full open. The propeller examination on November 12, 1993, revealed a stuck pilot tube, and the propeller was forwarded to the manufacturer for further examination. The manufacturer representative reported that the wood jammed in the hub and the bent pilot tube was "indicative of impacting the tree head on at a high power setting and a high rate of speed." He reported the blade angle at 28 degrees with the maximum being 31 degrees. The fuel flow indicator P/N 912021 was forwarded to the manufacturer (enclosed report) for documentation of the non- volatile memory. Upon power up, the system functioned normally and indicated the initial fuel load programmed into the system was 58 gallons. The autopilot system was examined (enclosed report) on November 29, 1993, and all the components, except the altitude transducer (which was not located), were removed from the airplane. During a detailed specification test (enclosed report) on December 12, 1993, the manufacturer stated that "all autopilot components functioned normally." ADDITIONAL INFORMATION: The airplane was released to the owner's representative.