Page:CAB Accident Report, United Air Lines Flight 823.pdf/11

 1.14

This accident was non-survivable and no studies were made of the structure from that standpoint.

1.15

The passenger that fell from the aircraft exited through an emergency window over the left wing. Witnesses who saw him fall said he did not strike the empennage but fell nearly straight down. An aerodynamic study as well as the body injury pattern confirmed the witness observations. He died of injuries received on impact with the ground. He had received burns on the hands, face and neck before death but had only a few carbon particles in his trachea and a carbon monoxide level of five percent in his blood. The upper portions of his clothes were impregnated with soot. There was no evidence of ground fire where the body was recovered.

The Armed Forces Institute of Pathology (AFIP) performed a number of tests of specimens from both crewmembers and passengers for the Board. Tests for carbon monoxide were not done on the flight crew due to a lack of suitable specimens. Passenger toxicological examination results were negative; no elevated carbon monoxide levels were found; no significant amount of alcohol was found; and tests for methylbromide yielded negative results. Histological examination of the seven recovered respiratory tract specimens revealed only a small number of carbon particles in each.

Federal Bureau of Investigation laboratory tests were accomplished to verify evidence of heat and smoke deposits; analyze various deposits on aircraft parts and on the free-fall victim's clothing, and evaluate possible evidence of sabotage. No residues were found to indicate that an explosion occurred aboard the aircraft. The reports did describe evidence of considerable heat or fire damage sooting to various components within the cabin, cockpit, and under the cabin floor aft of the cargo pit and forward of the main spar.

With the Board's concurrence, British Aircraft Corporation laboratory tests were conducted on samples of aircraft structure, components, and the free-all victim's clothing. These examinations consisted of exposure of ultra-violet light, X-ray, infra-red and emission spectroscopy, microscopic and visual observation. Their test results indicated that there was evidence of cabin fire on seats, windows, forward bulkhead trim, and the carry-on luggage rack. The sidewalls of the carry-on luggage rack had been exposed to temperatures on the order of 122°F., and the plastic material from a soundproof window had been exposed to temperatures of 620°F. They were best able to duplicate the heat damage to the free-fall victim's clothes by burning and quenching a fire of lighter fluid in a sample of the material. They did note the presence of black deposits on the bottom of seat track samples, taken from an area over the electrical bay, with none on the top of the samples. They concluded, however, that the deposits had more the characteristics of lacquer than soot.