|
United Airlines Flight 736 was a daily U.S. transcontinental passenger flight operated by United Airlines that crashed on April21, 1958, following a mid-air collision. The aircraft assigned to Flight 736, a Douglas DC-7 airliner carrying 47 persons, was flying at cruise altitude above Clark County, Nevada, en route to a stopover at Denver, Colorado, when it was struck by a United States Air Force fighter jet crewed by two pilots. The collision occurred at 8:30 a.m. in clear weather within a major commercial airway; both aircraft fell out of control from and crashed into unpopulated desert terrain southwest of Las Vegas, Nevada. There were no survivors from either aircraft, and with 49 fatalities it remains the deadliest crash in the history of the Las Vegas Valley. Among the victims were a group of military personnel and civilian contractors involved with sensitive Department of Defense weapons systems. The loss of the group triggered new rules prohibiting similar groups engaged in critical projects from flying aboard the same aircraft. The official investigation stated that cockpit visibility limitations played a role in the accident, but also faulted military and civilian aviation authorities for not taking measures to reduce well-known collision risks that had existed for over a year within the confines of airways, despite numerous complaints from airline crews. The loss of United Airlines Flight 736—part of a series of 1950s mid-air collisions in American skies, including the well-publicized 1956 Grand Canyon mid-air collision—helped usher in widespread improvements in air traffic control within the United States. ==Events leading to the accident== Flight 736, a four-engined DC-7 propliner with registration departed Los Angeles International Airport at 7:37 a.m. on a flight to New York City with stops in Denver, Kansas City and Washington, D.C. On board were 42 passengers and five crew members; Captain Duane M. Ward, 44, First Officer Arlin Edward Sommers, 36, Flight Engineer Charles E. Woods, 43, and Stewardesses Pauline Mary Murray, 22, and Yvonne Marie Peterson, 27. Of the passengers on the flight, seven were military personnel and 35 were civilians. Soon after takeoff the airliner was directed into airway "Victor 8," on a route that took it east over Ontario, California, and then northeast toward Las Vegas. The crew flew the DC-7 under instrument flight rules, controlled by Civil Aeronautics Authority (CAA) ground stations, at an authorized altitude of toward the first stopover at Denver. Approximately 8 minutes after the DC-7 had departed Los Angeles, a U.S. Air Force F-100F-5-NA Super Sabre jet fighter, serial number 56-3755, took off from Nellis Air Force Base near Las Vegas at 7:45 a.m. on a training flight with two pilots on board. In the front seat of the tandem cockpit was flight instructor and safety pilot Capt. Thomas N. Coryell, 29, and behind him sat his student, 1st Lt. Gerald D. Moran, 24, who as part of his training would spend the flight under a hood that blocked his view outside the aircraft, but allowed him to see his instrument panel.〔 The instructor had two-way microphone communication with the student, and his duties were to instruct the student in the rear seat, monitor his performance and maintain a lookout for other aircraft. The F-100F had dual pilot control and the instructor could take over flying the jet at any time. The training flight involved a descent and approach to Nellis Air Force Base under simulated instrument meteorological conditions from an altitude of . The descent was to be a "teardrop pattern," with the Las Vegas commercial radio station KRAM as the navigational fix, a process that was referred to as the "KRAM procedure." The prescribed descent angle for the KRAM procedure was about five degrees. At 8:14 a.m. the United Airlines crew radioed a routine position report over the Mojave Desert to notify controllers that they expected to arrive over McCarran Field near Las Vegas at 8:31 a.m. Air Force pilot Moran radioed the control tower at Nellis Air Force Base at 8:28 a.m. to report that he would now begin a procedural "jet penetration" descent to . As the fighter descended, the airliner was approaching Las Vegas air space at about on a heading of 23degrees, flying straight-and-level within the confines of its designated airway.〔(【引用サイトリンク】 ASN Aircraft accident Douglas DC-7 N6328C Arden, NV )〕 The CAA stations controlling the airliner were unaware of the fighter jet; the Air Force controllers at Nellis Air Force Base directing the jet were unaware of the airliner.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「United Airlines Flight 736」の詳細全文を読む スポンサード リンク
|