April 21, 1958, United Air Lines / USAF, Douglas DC-7 (N6328C) / North American F-100F (56-3755) Mid-Air Collision near Las Vegas, NV
ACCIDENT SYNOPSIS:
United Air Lines Flight 736, a DC-7 (N6328C), departed with 47 passengers and crew from Los Angeles (LAX) at 7:37 AM. Flight 736 was on a transcontinental flight to New York City (Idlywild) with a planned cruising altitude of 21,000 feet.
At about 7:45 AM, a US Air Force North American F-100F-5-NA Super Sabre fighter (56-3755) took off from Nellis AFB on an instrument training flight. During the exercise the flight was executing a simulated jet penetration in the area of Las Vegas, NV. At 8:30 AM, the fighter plane pilot reported that they were descending from 28,000 feet near the KRAM radio station. At the same time, United flight 736 was approaching the Las Vegas VOR.
Both aircraft collided head-on at 21,000 feet, nine miles southwest of the Las Vegas VOR station on Victor Airway 8. Initial contact occurred between the leading edge of the DC-7's starboard wing and the leading edge of the F-100's starboard wing. It was determined during the Civil Aeronautics Board (CAB) accident investigation that the DC-7 was flying at about 312 knots on a 023 degree heading and the F-100 at 444 knots on a 145 degree heading. Assuming a small descent angle of the F-100, the closure speed was close to 700 knots.
Both planes crashed out of control with the DC-7 entering a steep spiral dive. During the dive, three of the DC-7's four radial engines separated prior to impact. All persons on board both aircraft were killed.
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HISTORICAL SUMMARY:
The collision created two aircraft impact sites separated by seven miles, in addition to a large debris field between the two sites. During 1995, after much research and an extensive ground search, the DC-7 engine impact site was located. This discovery along with the discovery of the F-100F crash site by Craig Fuller of AAIR allowed the triangulation of the DC-7 main impact site.
When we first examined the DC-7 impact site, it appeared to be undisturbed with little evidence that an impact even took place. Reviewing old aerial photos, we decided to dig some test pits which revealed that the site (burned impact area) had been covered with a layer of top soil after the initial recovery work had been completed in 1958. The top soil not only concealed the site, but also formed a protective barrier from exposure. In effect it was a time capsule. However, with the population of Las Vegas growing, it was inevitable that the DC-7 impact site was in the path of future development.
Working with the landowner, we adopted a plan to map, excavate, document, and preserve the wreckage material we could recover. Over the following three years we excavated an area about 40 feet by 30 feet using a series of grids to mark not only where we excavated but also help document where we located items of interest. As a result, we recovered and documented hundreds of historical items during the excavations. Within a few short years the crash site of United Air Lines Flight 736 would be replaced by several commercial buildings and homes.
**UPDATE** June 2008, I visited the impact site of UAL Flight 736. A backhoe tractor had excavated a series of utility line trenches in front of the auto-tire center that was under construction. Visible in the freshly cut trench walls were the burned remnants of the DC-7 still covered in the top soil from 1958. I returned the next day and the trenches had been filled in.
Read MoreUnited Air Lines Flight 736, a DC-7 (N6328C), departed with 47 passengers and crew from Los Angeles (LAX) at 7:37 AM. Flight 736 was on a transcontinental flight to New York City (Idlywild) with a planned cruising altitude of 21,000 feet.
At about 7:45 AM, a US Air Force North American F-100F-5-NA Super Sabre fighter (56-3755) took off from Nellis AFB on an instrument training flight. During the exercise the flight was executing a simulated jet penetration in the area of Las Vegas, NV. At 8:30 AM, the fighter plane pilot reported that they were descending from 28,000 feet near the KRAM radio station. At the same time, United flight 736 was approaching the Las Vegas VOR.
Both aircraft collided head-on at 21,000 feet, nine miles southwest of the Las Vegas VOR station on Victor Airway 8. Initial contact occurred between the leading edge of the DC-7's starboard wing and the leading edge of the F-100's starboard wing. It was determined during the Civil Aeronautics Board (CAB) accident investigation that the DC-7 was flying at about 312 knots on a 023 degree heading and the F-100 at 444 knots on a 145 degree heading. Assuming a small descent angle of the F-100, the closure speed was close to 700 knots.
Both planes crashed out of control with the DC-7 entering a steep spiral dive. During the dive, three of the DC-7's four radial engines separated prior to impact. All persons on board both aircraft were killed.
*****************************************************************************************************************************
HISTORICAL SUMMARY:
The collision created two aircraft impact sites separated by seven miles, in addition to a large debris field between the two sites. During 1995, after much research and an extensive ground search, the DC-7 engine impact site was located. This discovery along with the discovery of the F-100F crash site by Craig Fuller of AAIR allowed the triangulation of the DC-7 main impact site.
When we first examined the DC-7 impact site, it appeared to be undisturbed with little evidence that an impact even took place. Reviewing old aerial photos, we decided to dig some test pits which revealed that the site (burned impact area) had been covered with a layer of top soil after the initial recovery work had been completed in 1958. The top soil not only concealed the site, but also formed a protective barrier from exposure. In effect it was a time capsule. However, with the population of Las Vegas growing, it was inevitable that the DC-7 impact site was in the path of future development.
Working with the landowner, we adopted a plan to map, excavate, document, and preserve the wreckage material we could recover. Over the following three years we excavated an area about 40 feet by 30 feet using a series of grids to mark not only where we excavated but also help document where we located items of interest. As a result, we recovered and documented hundreds of historical items during the excavations. Within a few short years the crash site of United Air Lines Flight 736 would be replaced by several commercial buildings and homes.
**UPDATE** June 2008, I visited the impact site of UAL Flight 736. A backhoe tractor had excavated a series of utility line trenches in front of the auto-tire center that was under construction. Visible in the freshly cut trench walls were the burned remnants of the DC-7 still covered in the top soil from 1958. I returned the next day and the trenches had been filled in.