HISTORY OF FLIGHT On May 12, 1994, at 2106 central daylight time, a Cessna 172P, N98723, was destroyed when it collided with the ground in Arlington, Texas. The airplane, owned by an individual, leased to a fixed base operator (FBO), and rented by an ATP rated pilot, was on a local personal flight. There was no flight plan filed and dark night visual meteorological conditions prevailed. Both the pilot and the one female passenger received fatal injuries. According to FBO personnel, the pilot called just prior to closing time and requested a rental airplane. As the pilot was known to the personnel, they agreed to stay late and make the rental. It was estimated by witnesses that the flight departed the Arlington Municipal Airport, sometime between 2045 and 2100. FBO and other personnel who observed the pilot and passenger, prior to departure, stated that both acted normally and appeared in good spirits. Several witnesses, who lived below the airport traffic pattern, stated that the airplane appeared to be traveling in an easterly to southeasterly direction at altitudes that they estimated varied from 1,000 to 1,500 feet AGL, flying straight and level with the engine sounding "normal." They further stated that they observed the airplane enter a maneuver that was variously described as an attempted loop or roll and subsequently descend below their line of sight. While some of the witnesses described the maneuver as a loop, they were all in agreement that the airplane initially entered a right bank and then dove toward the ground. They then heard the sounds of impact. WITNESSES In addition to the FBO personnel, there were three ground eyewitnesses and several ear witnesses who heard the airplane and impact while they were inside a building adjacent to the accident site. Written witness statements were obtained from all of the ground witnesses. None of the witnesses recalled seeing or hearing another aircraft in the area at the time of the accident. PERSONNEL INFORMATION The pilot was a corporate pilot who flew a Piper PA-31T that was based out of the Arlington airport. In addition, he was a part time instructor at the airport. He had successfully completed a biennial flight review in the PA-31T, on February 4, 1993. A review of the pilot's personal log book revealed that the last entry had been made on November 30, 1993. As a result, no determination as to his currency could be made. AIRCRAFT INFORMATION The airplane's total airframe and engine time was not determined during the investigation; however, an annual inspection had been performed on April 29, 1994, at a total airframe time of 6,819.8 hours. On the same date, hail damage to one window, the left wing tip, and a landing light lens was completed. The required altimeter, pitot static, and transponder checks had last been performed on February 2, 1993. COMMUNICATIONS The FAA had no record of the pilot receiving a weather briefing or filing a flight plan, nor did they have a record of any ATC communications with the airplane. Likewise, there were no reports of any distress calls from the pilot during the flight. Analysis of the recorded radar data, received from Dallas/Fort Worth Departure Control was inconclusive due to the lack of sufficient target hits during the time of the accident and the inability to distinguish the accident airplane. WRECKAGE AND IMPACT INFORMATION The airplane impacted in an open, grassy field about 2.5 miles southwest of the Arlington Municipal Airport. The measured heading on initial impact was 260 degrees. The wreckage was distributed along a path of 255 degrees for a distance of 290 feet. A complete frontal imprint of the airplane was left at the initial impact point. This included imprints from the engine, both wings, both struts, and all three landing gear. The main impact crater was about 18 inches deep. The battery and the separated propeller were found immediately adjacent to the main crater. In addition, pieces of appropriately colored navigation lens were found in the imprint of each wing tip, consistent with the airplane being upright at impact. The airplane was found disintegrated into five major pieces at the accident site. These consisted of the wings with a broken center section spar, the engine, the fire wall, the empennage and the horizontal and vertical tail planes, with the flight controls attached. All of the flight controls were accounted for at the accident site. Flight control continuity could not be established due to numerous breaks in the cable system. All of the breaks appeared to be overload in nature. The cockpit/cabin area was found disintegrated and the instrument panel separated with the fire wall. Destroyed instrumentation was found throughout the debris field. Both the front seats were found separated from their attachments. Both sides of the lap belt anchors were found pulled out of their respective floor attachments. The vacuum pump remained attached to the engine via the coupling; however, it exhibited impact damage. Both the left and right wings were compression damaged from front to rear throughout their span and chord. The propeller had separated at the bolt attachments. Both blades exhibited bending, twist, and chordwise striations and nicks. Several inches of one blade were missing and not found; however, the separation fracture appeared to be overload. Following removal from the field, rotational continuity was established from front to rear on the engine and compression was established on all of the cylinders. No evidence of pre-impact mechanical failure or malfunction was found during the examination. No evidence of inflight or post-crash fire was found during the investigation. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was ordered on the pilot and was performed by the Chief Medical Examiner's Office of Tarrant County. There were no significant findings on the autopsy. Toxicology studies were ordered on both occupants and performed by the Armed Forces Institute of Pathology for the FAA Civil Aeromedical Institute. The pilot's blood was positive for 0.3 mg/L of Diphenhydramine (antihistamine), which was in the therapeutic range. The FAA Southwest Region's Flight Surgeon wrote in his opinion that "The pilot should not have been taking Diphenhydramine for two reasons: (1) Definitely for the medication, most antihistamines can cause drowsiness, (2) Possibly for the underlying condition that was being treated." Standard precautionary notes for antihistamines, found in the Physician's Desk Reference, state that they may cause drowsiness or dizziness and that patients should observe caution while driving or performing tasks requiring alertness, coordination, or physical dexterity. The FAA regional flight surgeon stated that in addition to being contraindicated for flying, the use of antihistamines may mask the underlying condition being treated and induce vertigo. The toxicology studies on the passenger were positive for 26 mg/dL for Ethanol in the kidney sample. It was the flight surgeon's opinion that the finding was a result of postmortem ethanol production. ADDITIONAL INFORMATION Wreckage Release: The wreckage was released to the owner's representative on July 26, 1994. All of the retained records were released on that date.