Page:CAB Accident Report, Boeing Test Flight Crash on 19 October 1959.pdf/5

- 5 - The section of the left wing tip, severed by contact with the trees on the north side of the river, came to rest across the river approximately 50 feet before the first of the gouges which were dug in the ground by the remaining wing structure. The wing, from the point at which the tip was severed inboard to the landing gear beaver tail strap, was broken up and sections were scattered along the ground path. Most of these pieces received damage from ground fire and large areas were consumed completely. Inboard of the beaver tail the box section was nearly intact but partially consumed by ground fire, as was the center box section and inboard 30 feet of the right wing. The remainder of this wing was broken into two major pieces which were partially consumed in ground fire.

There was extensive inflight fire damage to the left wing in the area of the No. 2 engine, to the entire left side of the aft fuselage, and to the left side of the empennage.

The wing upper skin from the area of the aft end of the over wing pylon strap was identified. This skin was badly wrinkled by heat over each fuel vent channel and the skin over one was ruptured for a length of three feet. The edges of the rupture were curled outward, were very fibrous, and were heavily sooted, indicating that an explosion had occurred. In addition, rivets in the area which attached the skin to the vent were failed in tension.

From the rear spar aft, the wing trailing edge and flight controls were severely burned. The left inboard aileron and the entire trailing edge structure nearby were consumed except for small fragments. The inboard half of the No. 2 and the outboard half of the No. 3 spoilers were partly consumed. The outboard two feet of the No. 2 flap cove lip door was heavily sooted and a few small holes were burned in the skin. The internal structure in this area was consumed. The lower trailing edge just forward of the door was burned through and blackened.

The outer closing rib on the No. 2 flap was heat wrinkled. The flap lower surface was lightly sooted and the upper surface was heavily sooted. The inboard corner of the No. 1 flap was badly burned and three feet of its upper surface was consumed. It was determined that the flaps were extended approximately 28 degrees at impact. The left inboard spoiler valve fell from the aircraft about one mile from the crash site. It had large deposits of "runback" (solidified) aluminum on its lower side. The aileron trim mechanism and the aileron bellcranks also had these runback deposits on them. All control components in the area and even the rear wing spar web vertical stiffeners were badly burned by inflight fire.

The left side of the aft fuselage was heavily sooted and all of the windows were heat checked. In addition, paint on the rear loading door and on the fuselage aft to the stabilizer was blistered. Just forward of the vertical fin, light sooting angled across the fuselage top centerline and back along the upper right side of the tail cone and lower third of the right side of the vertical fin.

The lower half of the left side of the vertical fin was lightly sooted and paint was blistered and scorched. The lower balance panel covers were heat wrinkled. The lower half of the rudder was severely heat wrinkled. The left side of the tab was also heat wrinkled and heavily sooted. The right side of the rudder tab was lightly sooted from smoke which was drawn through the tab hinge, indicating right rudder trim during the fire.