United Airlines Flight 608


United Airlines Flight 608 was a Douglas DC-6 airliner, registration NC37510, on a scheduled passenger flight from Los Angeles to Chicago when it crashed at 12:29 pm on October 24, 1947 about southeast of Bryce Canyon Airport, Utah, United States. There were no survivors among the 5 crew members and 47 passengers on board. It was the first crash of a DC-6, and at the time it was the second deadliest air crash in the United States, surpassed by Eastern Air Lines Flight 605 by only one fatality.

Accident sequence

United Flight 608 departed from Los Angeles, California, at 10:23 a.m. on a routine flight to Chicago, Illinois. At 12:21 p.m. the airplane's pilot, Capt. Everett L. McMillen, radioed that there was a fire in the baggage compartment which they could not control, with smoke entering the passenger cabin. The flight requested an emergency clearance to Bryce Canyon Airport, Utah, which was granted.
As the aircraft descended, pieces of the airplane, including portions of the right wing, started to fall off and one of the emergency flares on the wing ignited. At 12:27 p.m., the last radio transmission was heard from the airplane: "We may make it - approaching a strip." Accounts from observers state the airplane passed over the canyon mesa, approximately from the airstrip. With gusts from the canyon floor flowing down the side of the mesa, the crippled aircraft, only off the ground, was pulled out of control and crashed.
Ground observers reported that occupants of the airliner, prior to the impact, were throwing various items out of the cabin door in an attempt to lighten the load as the DC-6 descended over the canyon. The airliner crashed onto National Park Service land, killing all 52 passengers and crew on board.
The October 25, 1947, edition of The Bridgeport Post reported the incident thus:

Cause of the crash

Just over three weeks later, on November 11, 1947, a similar in-flight incident almost claimed a second commercial DC-6 airliner.
An American Airlines DC-6, on a flight from San Francisco to Chicago with 25 crew and passengers aboard, reported an on-board fire over Arizona and managed to make an emergency landing in flames at the airport at Gallup, New Mexico. All 25 occupants escaped the burning plane, and the fire was extinguished. Unlike the Bryce Canyon crash a month earlier, investigators now had a damaged, but intact aircraft to examine and study.
The cause of both the Bryce Canyon crash and the near-fatal Gallup incident was eventually traced to a design flaw. A cabin heater intake scoop was positioned too close to the number 3 alternate fuel tank air vent. If flightcrews allowed a fuel tank to be overfilled during a routine fuel transfer between wing tanks, it could lead to several gallons of excess fuel flowing out of the tank vent and then being sucked into the cabin heater system, which then ignited the fuel. This caused the fire which destroyed the United aircraft at Bryce Canyon and severely damaged the American aircraft that landed in flames at Gallup.
In the Bryce Canyon crash, the Civil Aeronautics Board found the causes to be the design flaw, inadequate training of the crew about the danger, and the failure of the crew to halt the fuel transfer before the tank overflowed.

Aftermath

The procedures developed as a result of this disaster make this crash historically important. It was the first time an airplane was reconstructed from its wreckage to help determine the cause of the crash. This is now a standard procedure.
Wreckage was loaded onto trucks and moved to Douglas Aircraft Company in California where the airplane was reassembled.
As a result of the disaster the entire fleet of 80 Douglas DC-6 aircraft, including the U.S. President's aircraft, were ordered grounded and recalled. Design changes that were made thereafter still stand today.