Douglas DC-4 accident at Cheyenne, Wyoming, 8 Oct 1946

Accident narrative

On October 8, 1946, at 0433 MST, United Air Lines Flight 28 crashed during an approach to the Cheyenne, Wyoming, Airport. The Douglas DC-4 struck the ground on the Fort Warren Military Reservation, approximately half a mile northwest of the airport. The aircraft was demolished; two passengers were killed, and all other occupants were injured.

**The flight** Flight 28 of October 7 was scheduled from San Francisco, California, to Chicago, Illinois, with an intermediate stop at Cheyenne. Due to a late arrival, it departed San Francisco at 2220 PST. Aboard were 43 passengers, including three infants, and a crew of four.

Captain Leonard L. Smith had 12,573 flight hours, including 2,125 in DC-4s. First Officer Jerome L. Buchman had 3,551 hours, including 831 in four-engine aircraft. This was their first flight together. The aircraft carried 3,959 pounds of cargo and 1,600 gallons of fuel, and was cleared to cruise at 13,000 feet with Denver, Colorado, as the alternate.

**The approach** The flight proceeded uneventfully. Over Salt Lake City, the crew was informed that Denver had a zero ceiling, but that weather at Rock Springs, Wyoming, was good. Near Sinclair, Wyoming, the altimeters were set to the Cheyenne pressure of 29.96 inches. At 0357, the flight reported 55 miles from Cheyenne at 13,000 feet. Cheyenne broadcast its weather as an indefinite ceiling of 500 feet, visibility 5 miles, light fog, and clear to the west.

At 0105, the Cheyenne tower cleared the flight to land on Runway 26. The crew replied they would make an instrument let-down. The flight reported over the Cheyenne Range Station at 9,000 feet.

Following the company's let-down procedure, the Captain flew out the east leg and descended to 7,000 feet headed west. He did not receive the position identifying signal from the Archer Fan Marker, and when visual contact was established, the aircraft was too high to land. The Captain made a left turn, descending to about 6,500 feet (360 feet above the field), where he could occasionally see the ground. He proceeded out the east leg again, climbed to 7,000 feet, received the marker signal, and returned over the marker. Upon establishing visual contact, he was again too high. The Captain stated this was his last east-to-west attempt; however, the First Officer and ground witnesses testified that the aircraft circled left again and made another landing attempt.

The Captain then decided to approach from the west, where visibility had been fair. Cleared to land on Runway 12, he started a gradual left turn at the western boundary of the field, then entered a right turn to line up with the runway. This right turn was continued at an altitude of about 200 feet above the ground with wheels down, 15 degrees of flap, and an airspeed of approximately 120 mph.

The Captain instructed the First Officer, who occupied the right seat on the low side of the turn, to "sing out" when he saw the field. When the First Officer said, "There's the field at 2 o'clock," the Captain leaned to the right to see it himself. During this momentary diversion from the instruments, enough altitude was lost for the right wing tip to strike the ground.

At the instant of impact, the aircraft was in a 15-degree right bank and headed northeast. It came to rest about 700 feet beyond the point of first impact. A gasoline fire developed along the crash path and partly burned the separated right wing, but the main wreckage continued ahead of the fire and did not burn.

**What the investigation found** The Board found no evidence of malfunction in the aircraft, its engines, or the radio facilities. The flight instruments had recently been rearranged, but the Captain believed this did not impair his use of them. Both altimeters were set correctly.

Company weather minimums for night operations at Cheyenne were a 400-foot ceiling and two miles visibility. The officially reported weather at the time of the crash was an indefinite ceiling of 400 feet, visibility 5 miles, and light fog. The Board noted that due to fog, visibility decreased with elevation, and the actual ceiling encountered must have been lower than reported, as both pilots testified they could not maintain visual contact while no higher than 300 feet above the runway.

The company's operations manual allowed descent to 400 feet above the airport when the ceiling was "indefinite." If visual contact was made, the pilot could descend another 50 feet during maneuvering. The Captain testified that his altimeter showed he was less than 400 feet above the ground during the passes and the final turn. He stated to investigators, "...I made the fatal mistake of not making the turn with my eyes on the instruments..."

The Board noted that the approved missed-approach procedure was not instituted at any time. Furthermore, Rock Springs, 231 miles away, had a 6,500-foot ceiling and 40-mile visibility, and the aircraft had ample fuel to proceed there. Following the accident, the Board amended the Civil Air Regulations to eliminate any qualification of the word "ceiling" to prevent the practice of descending below minimums to take a look.

**Probable cause** The Board determined that the probable cause of this accident was "a loss of altitude during a turn preparatory to a final approach while the pilot was maneuvering in an attempt to land."