United Airlines

On July 11, 1961, at 1136 M.S.T., a United Air Lines DC-8 crashed during its landing roll at Stapleton Airfield, Denver, Colorado. None of the 122 occupants was severely injured as an immediate result of the impact; however, there were 16 passenger fatalities as a result of carbon monoxide poisoning when the aircraft burned. One other passenger, an elderly woman, broke both ankles during evacuation of the airplane and later succumbed to shock. In addition, the driver of a panel truck, which the aircraft struck after leaving the runway, also suffered fatal injuries. After experiencing hydraulic difficulties following takeoff from Omaha, Nebraska, the crew of N8040U continued the flight to Denver, using procedures set forth in the flight manual for abnormal hydraulic situations. When the flight arrived in the Denver area, preparations were made for landing. The ejectors were extended hydraulically, however, when an attempt was made to extend flaps to 25 degrees the hydraulic pressure dropped to zero. The hydraulic system selector was then placed in the No. 3 position (flap and gear downlock), and the approach was continued. After touchdown, the throttles were placed in the idle reverse thrust position and when power was applied, an uncontrollable deviation from the runway occurred.

On December 16, 1960, at 1033 e.s.t., a collision between Trans World Airlines Model 1049A Constellation, N 6907C, and a United Air Lines DC-8, N 8013U, occurred near Miller Army Air Field, Staten Island, New York. Trans World Airlines Flight 266 originated at Dayton, Ohio. The destination was LaGuardia Airport, New York, with one en route stop at Columbus, Ohio United Air Lines Flight 826 was a non-stop service originating at O'Hare Airport, Chicago, Illinois, with its destination New York International Airport, New York. Both aircraft were operating under Instrument Flight Rules. Following the collision the Constellation fell on Miller Army Field, and the DC-8 continued in a northeasterly direction, crashing into Sterling place near Seventh Avenue in Brooklyn, New York. Both aircraft were totally destroyed. All 128 occupants of both aircraft and 6 persons on the ground in Brooklyn were fatally injured. There was considerable damage to property in the area of the ground impact of the DC-8. TWA Flight 266 departed Port Columbus Airport at 0900, operating routinely under Air Traffic Control into the New York area The New York Air Route Traffic Control Center (ARTCC) subsequently advised that radar contact had been established and cleared the flight to the Linden. Intersection, Control of the flight was subsequently transferred to LaGuardia Approach Control. When the flight was about over the Linden Intersection, LaGuardia Approach Control began vectoring TWA 266 by radar to the final approach course for a landing on runway 4 at LaGuardia. Shortly thereafter TWA 266 was cleared to descend to 5,000 feet, and was twice advised of traffic in the vicinity on a northeasterly heading. Following the transmission of this information the radar targets appeared to merge on the LaGuardia Approach Control radar scope, and communications with TWA 266 were lost.United Air Lines Flight 826 operated routinely between Chicago and the New York area, contacting the New York ARTCC at 1012 Shortly thereafter the New York Center cleared UAL 826 to proceed from the Allentown, Pa., very high frequency omni directional radio range station (VOR) direct to the Robbinsville, New Jersey, VOR, and thence to the Preston Intersection via Victor Airway 123. At approximately 1021, UAL 826 contacted Aeronautical Radio, Inc. (ARINC) to advise their company that the No. 2 receiver accessory unit was inoperative, which would indicate that one of the aircraft's two VHF radio navigational receivers was not functioning. A "fix" is established by the intersection of two radials from two separate radio range stations. With one unit inoperative the cross-bearings necessary can be taken by tuning the remaining receiver from one station to the other. This process consumes considerable time, however, and is not as accurate as the simultaneous display of information on two separate position deviation indicators While UAL 826 advised the company that one unit was inoperative, Air Traffic Control was not advised. At 1025 the New York ARTCC issued a clearance for a new routing which shortened the distance to Preston by approximately 11 miles. As a result, this reduced the amount of time available to the crew to retune the single radio receiver to either the Colt' s Neck, New Jersey, or Solberg, New Jersey, VOR in order to establish the cross-bearing with Victor 123, which would identify the Preston Intersection. In the event the crew would not attempt to retune the single VOR receiver, crossbearings on the Scotland Low Frequency Radiobeacon could be taken with the aircraft direction finding (ADF) equipment. This would be a means of identifying the Preston Intersection but, under the circumstances, would require rapid mental calculation in the interpretation of a display which could be easily misread. Several factors support the conclusion that this occurred. Instructions had been issued to UAL 826 for holding at the Preston Intersection the clearance limit, should holding be necessary. Clearance beyond Preston for an approach to Idlewild Airport would be received from Idlewild Approach Control and the transfer of control of the flight from the New York Center to Idlewild Approach Control would normally take place as the aircraft was approaching Preston. UAL 826 was not receiving radar vectors, but was providing its own navigation. After the flight reported passing through 6,000 feet the New York Center advised that radar service was terminated and instructed the flight to contact Idlewild Approach Control. UAL 826 then called Idlewild Approach Control, stating "United 826 approaching Preston at 5,000." This was the last known transmission from UAL 826. At the time UAL 826 advised it was approaching Preston it had in fact gone on by this clearance limit several seconds before and was several miles past the point at which it should have turned into the holding pattern. This is confirmed by the data obtained from the flight recorder which had been installed in the UAL DC-8, as well as by analysis of the communication tapes At a point approximately 11 miles past the Preston Intersection a collision occurred between TWA 266 and UAL 826. Weather at the altitude of the collision and at the time of the accident was such as to preclude flight by visual means.

United Airlines Flight 736 departed Los Angeles International Airport at 0737 hours Pacific standard time with 42 passengers and 5 crew aboard. It was a scheduled passenger flight to New York, which was proceeding normally in accordance with an IFR flight plan along Victor Airway 16 to Ontario, California, and Victor Airway 8 to Denver. The aircraft was cleared to a cruising altitude of 21 000 ft msl and advised to climb in VFR weather conditions. At 0735 the flight reported to Aeronautical Radio that it was over Ontario at 12 000 ft and was climbing in VFR conditions. Then at 081 1 it reported over Daggett at its cruising altitude of 21 000 ft and estimated that it would reach Las Vegas (omni range station) at 0831, This was the last position report made by the flight. At approximately 0745 hours that morning F-100F, 56-3755, took off from Nellis Air Force Base, Las Vegas, Nevada on an instrument training flight carrying an instructor and a trainee pilot. The flight was in accordance with a VFR local flight plan filed with Nellis Operations and the local traffic control tower. At approximately 0823, 755 called Nellis VFR Control and reported that it was "inbound on KRAM" ( a local commercial radio broadcast station). The flight requested an altitude assignment from which it would conduct a simulated ADF instrument jet penetration utilizing KRAM. The VFR controller assigned 755, 28 000 ft and advised it to report over the radio station. At approximately 0828, the flight reported that it was over KRAM requesting a penetration. The VFR controller cleared it for an immediate penetration and requested that it report the penetration turn. 755 then reported leaving 28 000 ft. There were no &her reports from the flight in connection with this procedure. At 0830 the offices of Aeronautical Radio at Los Angeles, Denver and Salt Lake City heard an emergency message from the United flight.. . . . " United 736, Mayday, midair collision, over Las Vegas. " At the same time, as nearly as can be determined, there was an unrecorded emergency transmission from the F-1 00F. This message was heard by the VFR controller and by the two pilots of another F-100F. All were agreed that the first portion of the emergency transmission was "Mayday, Mayday, this is 755. " The last part of the message was either, "We've had a flameout" or 'We're bailing out." The aircraft collided at 21 000 ft over a position later determined to be about 9 miles southwest of the Las Vegas VOR station, on Victor Airway 8, approximately 1-3/4 miles to the right (southeast) of the centerline. Both aircraft fell out of control and crashed killing the 47 persons on board the DC-7 and both pilots of the F-100F.

United Air Lines Flight 718 was regularly scheduled from Los Angeles to Chicago, Illinois. On June 30, 1956, it took off from runway 25L (left) of the Los Angeles International Airport at 0904 (three minutes after TWA 2). Flight 718 was on an IFR flight plan to Chicago via Green Airway 5 Palm Springs inter-section, direct Needles, direct Painted Desert, direct Durango, direct Pueblo, direct St. Joseph. Victor Airway 116 Joliet, Victor Airway 84 Chicago Midway Airport. The flight plan proposed a .JPG"> airspeed of 288 knots., a cruising altitude of 21,000 feet, and a departure time of 0845. The flight crew consisted of Captain Robert F. Shirley, First Officer Robert W. Harms, Flight Engineer Gerard Flore, and Stewardesses Nancy L. Kemnitz and Margaret A. Shoudt. Flight preparations and dispatch of United 718 were routine and the aircraft departed with 3,850 gallons of fuel. The company load manifest showed the gross weight of the aircraft at takeoff to be 105,835 pounds, which was less than the maximum allowable of 114,060 pounds; the latter weight was restricted from a maximum of 122,200 pounds for the aircraft because of a landing limitation at Chicago. The load was properly distributed with respect to the center of gravity limitations of the aircraft. After takeoff the flight contacted the Los Angeles tower radar controller, who vectored it through the overcast over the same departure course as TWA 2. United 718 reported "on top" and changed to Los Angeles Center frequency for its en route clearance. This corresponded to the flight plan as filed; however, the controller specified that the climb to assigned altitude be in VER conditions. Flight 718 made position reports to Aeronautical Radio, Inc., which serves under contract as United company radio. It reported passing over Riverside and later over Palm Springs intersection. The latter report indicated that United 718 was still climbing to 21,000 and estimated it would reach Needles at 1000 and the Painted Desert at 1034. At approximately 0958 United 718 made a position report to the CAA communications station located at Needles. This report stated that the flight was over Needles at 0958, at 21,000 feet, and estimated the Painted Desert at 1031, with Durango next. At 1031 an unidentified radio transmission was heard by Aeronautical Radio communicators at Salt Lake City and San Francisco. They were not able to understand the message when it was received but it was later determined by playing back the recorded transmission that the message was from United 718. Context was interpreted as: "Salt Lake, United 718 . . . ah . . . we're going in."

After a routine radio ramp check, Flight 629 taxied to runway 08R (80 degrees, right) and at 1844 the flight was in runup position where it was given ATC clearance for the flight to Portland, the first intended landing. The clearance, in part, included compulsory radio reports from the flight upon passing the Denver Omni and when climbing through 18,000 feet to its assigned flight altitude, 21,000 feet. Following takeoff the flight reported its "off time" to the company as 1852 and thereafter reported passing the Denver Omni at 1856. The latter communication was the last from the flight. About 1903 the Denver tower controllers saw two white lights, one brighter than the other, appear in the sky north-northwest of the airport and fall to the ground. Both lights were observed 30-45 seconds and seemed to fall with approximately the same speed. There was then a momentary flash originating at or near the ground which illuminated the base of the clouds, approximately 10,000 feet above. When the controllers observed the lights they initiated action to determine if any aircraft were in distress. Radio calls were made to all aircraft in the Denver area of responsibility and all except flight 629 were accounted for. It was soon learned that the flight had crashed and all 44 occupants had been killed. It was later confirmed that the disintegration of the aircraft in the air was caused by a bomb. Two weeks later, on November 15, investigators confirmed that an explosive device has been placed on board by John Gilbert Graham aged 23 who signed a US$ 37,500 life-insurance for his mother who was on board. Convicted guilty for murder and terrorism, he was sentenced to death penalty and executed on January 11, 1956.

Flight 409 originated at New York, New York, on October 5, 1955, destination San Francisco, California, with intermediate stops including Chicago, Illinois, Denver, Colorado, and Salt Lake City, Utah. The trip to Denver was routine except for traffic delays, caused principally by weather, and the flight arrived there at 0551, October 6, one hour and 11 minutes late. Routine crew changes were made at Chicago and Denver, the last crew consisting of 'Captain Clinton C. Cooks, Jr., First Officer Ralph D. Salisbury, Jr., and Stewardess Patricia D. Shuttleworth. No discrepancies were reported by the former crew and none were found at Denver. While at Denver the aircraft was refueled to a total of 1,000 gallons of gasoline. Prior to departure Captain Cooke was briefed by the company's dispatcher on the en route weather, based on both U. S. Weather Bureau sequence reports and forecasts and the company meteorologist's forecasts and analysis. Following this briefing the flight me dispatched to Salt Lake City via airways V-4, V-118, V-6, and V-32, to cruise at 10,000 feet, and to fly in accordance with Visual Right Rules (VFR). The estimated time en route was two hours and 33 minutes. The only obligatory reporting point along the route was Rock Springs, Wyoming. The flight departed Denver at 0633, with 63 passengers, including two infants. At takeoff, the gross weight of the aircraft was 64,147 pounds, 653 pounds under the allowable weight of 64,800 pounds; an error of 100 pounds in excess of the allowable rear baggage compartment weight 2 was made in loading. Flight 409 reported its time off to the company and this was the last known radio contact with the flight. When the flight failed to report at Rock Springs at 0811, its estimated reporting time, repeated efforts were wade to establish radio contact with it. These were unsuccessful and the company then declared an emergency. A widespread search was immediately coordinated by Air Search and Rescue, which included the Wyoming Air National Guard, the Civil Air Patrol, and United Air Lines. At approximately 1140 the same day the wreckage was sighted near Medicine Bow Peak, 33 miles west of Laramie, Wyoming. The Laramie weather at 0728 was; Scattered clouds, 5,500 feet; visibility 40 miles; wind west-northwest 13 knots; snow showers of unknown intensity over the mountains. The aircraft struck the almost vertical rock cliff of the east slope of Medicine Bow Peak (elevation 12,005 feet) located in the Medicine Bow Mountains. The crash occurred at an elevation of 11,570 feet, 60 feet below the top of that portion of the mountain directly above it. Two large smudge marks were apparent on the face of the mountain. In these marks were four scars, evenly spaced and in a horizontal line, the result of the engines and propellers of the aircraft striking the cliff. At impact the aircraft disintegrated and the wreckage me strewn over a wide area. Some parts were thrown to the mountain top above the crash site, others rested on ledges at various levels, and the remainder fell to the elope below. All 66 occupants have been killed.

N37512, under the command of Captain S. C. Hoyt, UAL New York area flight manager, departed New York International Airport at 1428 on a Visual Flight Rules flight plan for an estimated two-hour flight in the vicinity of MacArthur Field, Islip. The aircraft was properly dispatched on a routine check flight, and Captains V. H. Webb and H. M. Dozier were aboard for the purpose of receiving their periodic instrument proficiency check. Upon completion of the checks, the flight was scheduled to return to LaGuardia Airport. At 1501 the flight reported to the company by radio that they were “doing air work around Hempstead.” Another message was received by the company at 1527 reporting that the flight was going to make an ILS (Instrument Landing System) approach at Islip (MacArthur Field). Shortly thereafter, the flight contacted the MacArthur tower, requesting approval for an ILS approach and landing. Permission was granted by the tower, and a normal landing was made on runway 32. The aircraft was taxied to the intersection of runways 28 and 32 and the crew prepared for takeoff. The 1532 MacArthur weather observation showed scattered clouds at 20,000 feet, broken clouds at 25,000; visibility over 15 miles; temperature 53; dew-point 30; wind NNW at 20 knots, gusts to 30 knots. When the flight departed New York International Airport, weather was approximately the same and the forecast for the New York area indicated that it would be similar over the area for the duration of the flight. At 1548, the MacArthur controller cleared the flight to take position on runway 32 and take off. The aircraft took position on the runway but did not immediately take off, hence a second takeoff clearance was transmitted at 1550. The gross weight of the aircraft at takeoff from MacArthur Field was approximately 61,050 pounds, which was well below the maximum allowable. The load was correctly distributed with respect to center of gravity limits. The aircraft became airborne approximately, 1,500 to 1,800 feet down the runway. The takeoff appeared normal, as did the initial portion of the climb, and the aircraft remained on the runway heading. When about 50 feet high, the right wing lowered and the aircraft started turning to the right, at which time the landing gear was retracting. The aircraft continued a climbing turn and the degree of bank increased to approximately vertical by the time the heading changed about 90 degrees and the aircraft had attained an estimated altitude of 150 feet. The nose dropped sharply and the aircraft dived into the ground, striking on the right wing and nose. It then cartwheeled and came to rest right side up. An intense fire started and consumed a large portion of the wreckage in spite of the prompt arrival of fire fighting equipment on the field.

Flight 329 departed Des Moines on a VFR (Visual Flight Reed) night plan at 1608 for Omaha, Nebraska. The gross weight of the aircraft was 45,215 pounds 1,685 pounds less than the allowable 46,900 pounds. According to company records, the load was properly distributed with respect to the canter of gravity of the aircraft. The climb to 5,000 feet was uneventful but at that altitude the crew noticed vibration and a slight fore-and-aft movement of the control column. The climb was continued to 6,000 feet, where the aircraft was leveled off and power was reduced. As the vibration was still present at this time, the captain attempted to dampen it by engaging the autopilot; however, this was unsuccessful and it was immediately disengaged. The first officer next lowered the flaps, first to 5 degrees and then to 15 degrees, without any noticeable effect. The “Fasten Seat Belt" sign was turned on and the captain told the first officer to advise the company of their difficulty via radio. About this time a sudden failure in the control system was felt and it was with extreme difficulty that any semblance of elevator control was maintained. The first officer again tried lowering the flaps, this time to the 24-degree position, but as this did not help to maintain control he returned them to the 15-degree position, where it was found the most favorable results were attained. Accordingly, the first officer transmitted "Mayday” (distress call) on the radio and said that they were attempting to return to Des Moines but were experiencing control trouble. The buffeting became so severe it was then necessary for the copilot to help the can hold the control column. However, the buffeting lessened and the captain advised the first officer to depressurize the aircraft and tell the stewardess to prepare the passengers for an emergency landing. This was done. By that time the aircraft had descended below 3,000 feet. Both throttles were retarded in turn to see if the trouble could possibly be caused by one of the engines. This also proved to no avail. The vibration built up to high level and suddenly another failure in the control system was felt and the air-plane went into a steep climb. As it seemed that a stall was imminent, the captain quickly moved the propellers to a high r. p. m. and pushed the throttles forward until about 50 inches of manifold pressure was seen on the gauges. The airplane then nosed over and began to dive at a very steep angle. During this rapid descent the captain reduced power and headed toward open country to his right. When the aircraft reached 500 feet above the ground the captain was successful in flaring the aircraft and it struck the ground in a flat attitude. All occupants were quickly deplaned as soon as the aircraft stopped.

United Air Lines operates a Flight Training Center at Denver, Colorado, to train applicants for first officer positions with the company. The crew of United Trainer 16 consisted of Senior First Officer Jordan D. Kocher, who had been designated by United Air Lines as captain and instructor, and Trainee First Officers Laurence G. Wilson and Wayne C. Moen. The flight departed Stapleton Airfield at 0655LT. The 0628 weather conditions, upon which the crew had been briefed, were ceiling measured 15,000 feet, visibility 25 miles, and wind northwest 14 knots Ceiling and visibility were unlimited at the time of the accident, with the wind northwest 16 knots. No radio contacts were made by United Trainer 16 after reporting departure time. It was cleared for a training flight of four hours’ duration within a 25-mile radius of Denver Captain Kocher occupied the left pilot’s seat at takeoff. Upon departure, the aircraft load, in addition to the crew, was 820 gallons of gasoline, full oil tanks, and 650 pounds of sand ballast tied down in the rear baggage pit. The load was properly distributed with relation to the aircraft’s center of gravity, and the 22,910-pound gross weight at takeoff was within allowable limits. Witnesses reported that at between 0720 and 0725 the aircraft was seen to stall, enter a spin, and strike the ground in a diving attitude before recovery was effected.

The flight departed San Francisco at 1042, operating as "United Trainer 7030." Flight Manager Frederick S. Angstadt was captain and was being given his semi-annual instrument check by Assistant Flight Manager Hugh C. Worthington, who served as copilot. Flight Engineer Charles K. Brogden was the third crew member. In addition to the foregoing instrument check, consideration had been given to investigating the feasibility of using the Oakland, California, Municipal Airport for certain phases of crew training in this type aircraft for a new class of pilots and flight engineers which was to convene that afternoon. Captains Angstadt and Worthington were to supervise this training. United Air Lines' officials stated that Captains Angstadt and Worthington intended to make this determination during the flight. Captain Angstadt was given the 0928 sequence weather reports for the local area prior to completing a clearance form at the UAL dispatcher's office. Pertinent weather was as follows: stratus clouds in the Bay area with tops at approximately 1,600 feet; San Francisco and Oakland - 800 foot ceiling, overcast, visibility three miles, haze and smoke; ceiling and visibility at Fresno and Sacramento unlimited. The forecast for the Bay area indicated scattered clouds by 1100 PST. Clearance was issued for local flight under Visual Flight Rules (VFR), confined to a 100-mile radius from San Francisco and under 10,000 feet. The load was properly distributed with respect to permissible center of gravity limits. Gross weight of the aircraft at takeoff was 114,886 pounds with 4,700 gallons of fuel, well under the maximum permissible gross takeoff weight. After reporting on top of the broken scattered clouds to the San Francisco tower at 1046, the flight proceeded to Oakland. The Oakland tower approved a simulated Instrument Landing System approach; this and a missed approach procedure were performed. The flight again reported on top at 1136. Another simulated ILS approach was requested of the Oakland tower but the flight was advised that there would be a delay due to other traffic. In view of this, the pilot decided to return to San Francisco. The flight changed frequency from the Oakland tower to San Francisco Approach Control at 1137. At 1139, the flight was cleared for an ILS approach to the San Francisco Airport, but did not acknowledge the clearance on the 119.1 megacycle Approach Control frequency. Following two attempts to contact the flight, the controller heard the aircraft make an unreadable call on 121.9 megacycles, and instructed the flight to listen on 119.1. This transmission was followed by further instruction for the flight to hold VFR, and stand by. The frequency change was apparently accomplished by the flight and the pilot again requested permission to make a simulated ILS approach. The request was granted, with instructions to report upon leaving the ILS outer marker inbound. This message and one other were not acknowledged by the flight. No emergency call was received from the aircraft. The crash was reported to the U. S. Coast Guard Air Station at 1046 by the manager of a nearby airport.