Page:CAB Accident Report, Pan Am Flight 102.pdf/3

 The foaming operation was completed by about 2325 and the emergency vehicles were recharged with foam and water. By 0010 the emergency equipment was made ready and positioned for the landing. A final check was made to make certain that the runway was clear of personnel. After insuring that all unauthorized persons were north of taxiway Q, which is 850 feet north of runway 13R, the control tower was notified that preparations were complete.

The captain, after receiving landing clearance from the tower, made his final preparations for the landing. Based on the gross weight of the aircraft, which was estimated to be 155,000 to 158,000 pounds, reference speed was calculated to be 130 knots and the approach was made.

Flaps were fully extended and touchdown was made within the first 1,000 feet of the runway with the right main gear. Spoilers were raised immediately and as the left main gear and nose wheels made contact full reverse thrust was applied. It was possible to hold the aircraft straight using differential reverse thrust until the full weight settled on the left gear and the left strut began to drag on the runway. Right brake was sufficient to maintain directional control and at 0029 the aircraft came to a stop on the runway about 1,200 feet short of the foamed area.

Although the strut and scraping on the runway generated heavy sparking throughout the landing roll, no fire occurred. Immediately after the aircraft stopped, the exit door were opened and emergency slide chutes were released.

The Port Authority emergency vehicles surrounded the aircraft to assist in evacuating the passengers. Several people left the aircraft via the chutes; however, within a short period of time the chutes were cut away and the remaining passengers were evacuated via emergency stairs placed in position by Port Authority personnel. All 102 passengers were out of the aircraft in approximately three minutes. It was estimated that approximately 400 to 600 people surrounded the aircraft after it stopped. Most of the persons were the curious whose presence seriously hampered the efforts of the rescue workers. As there was no danger of tires blowing out or the collapse of the damaged landing gear, the sightseers were repeatedly asked to "move out of the danger area." These warnings were ignored and finally a Port Authority fire truck sprayed the crowed and cleared the area.

Examination of the forward section of the hollow steel truck beam for the left landing gear revealed the presence of a flat peen mark on its top face 7-1/2 inches forward of the truck fulcrum. A crack extending longitudinally approximately 1-1/2 inches each way from the peen mark was evident. Although the clamshells and polishing normally associated with metal fatigue were not present, there were the well-defined lines of a fatigue-like crack which started at the inside surface of the truck beam. The end lines and the lack of ductility indicate the probability of more than one cycle of loading. Beyond these end lines the longitudinal crack was extended in instantaneous fractures 3-1/2 inches forward and 1-3/8 inches behind.

A second less well-defined peen mark was found about one-half inch forward of the above described peen mark. Although this second mark appeared to have been make by a sharper edge, no evidence of fatigue was present. A peripheral