Convair 240-1 accident at Daggett, California, 25 Jul 1957
On July 25, 1957, a Convair 240-1 operated by Western Airlines was involved in an aviation accident near Daggett, California. Investigators recorded the probable cause as: The Board determines that the probable cause of this accident was the act of a passenger in exploding dynamite in flight. This summary draws on records from the U.S. Civil Aeronautics Board (CAB) accident report collection at the National Transportation Library; 8 related events involving the same aircraft type or operator are linked below.
Probable cause
The Board determines that the probable cause of this accident was the act of a passenger in exploding dynamite in flight.
— NTSB Determination
Accident narrative
On July 25, 1957, an explosion occurred in the lavatory of Western Air Lines Flight 39 while flying near Daggett, California. The blast ruptured the fuselage shell, and outrushing air from the pressurized cabin enlarged the opening. A passenger, who the Civil Aeronautics Board concluded intentionally detonated dynamite, was blown out of the aircraft. The Convair 240-1 landed safely at George Air Force Base in Victorville, California, with no injuries to the remaining occupants.
### The flight
Western Air Lines Flight 39 was a scheduled passenger service originating in Rochester, Minnesota, for Los Angeles, California. Following a regular crew change at Salt Lake City, Captain Milton L. Shirk, First Officer Seth M. Oberg, and Stewardess Joan M. Hollinger took over the flight. Captain Shirk had 9,745 flying hours, including 3,092 in the Convair 240-1.
The aircraft arrived at Las Vegas, Nevada, at 0221 and departed at 0255 under visual flight rules. The takeoff weight was 35,300 pounds, well under the maximum allowable weight of 40,909 pounds, and the load was properly distributed. On board were 12 adult passengers and one infant. The crew was cleared to Los Angeles via Victor Airway 21, to maintain 12,000 feet.
### The explosion
At 0324, the flight reported leaving 12,000 feet to descend to 10,000 feet. At 0331, Flight 39 reported over Daggett at 10,000 feet. Captain Shirk informed the company that the aircraft and radio were operating normally, though the cabin cooling was not working properly; pressurization was at maximum and airflow was excellent, but warm.
About 0337, a loud noise came from the rear of the airplane. The first officer, who was flying, stated the explosion and explosive decompression sounded like someone had fired a double-barreled shotgun behind his head. He noted no fumes and stated the airplane continued to fly normally. Captain Shirk scanned the instruments, noting the altitude was exactly 10,000 feet, cabin pressurization was set to 4,000 feet (approximately 2.3 psi), and the airspeed was 185 knots. The engines and radios continued to operate normally. Neither pilot noticed any cabin pressure fluctuation just prior to the decompression.
A quick inspection by flashlight revealed a hole in the right side of the fuselage, just aft of seat 10-D and forward of the right stabilizer, in the area of the lavatory. The captain radioed the company, declared an emergency, and diverted to George Air Force Base, landing without further incident at 0348.
Stewardess Hollinger had been sitting in seat 10-D, just ahead of the lavatory well, having recently checked that all passenger seat belts were secured. She described hearing a horrible blast and a terrific gush of wind, after which the cabin filled with thick fog and an eerie light. The window on her right shattered. She moved the rear passengers forward and conducted a quick count, finding 11 adults and one infant. Passenger Saul F. Binstock, 62, who had boarded in Las Vegas, was missing.
Witnesses stated that about 15 minutes after takeoff, Binstock had left his seat on the left side of the cabin and entered the lavatory on the right. He remained there for approximately 20 minutes until the explosion occurred.
### What the investigation found
The Board ruled out mechanical or structural failure of the aircraft, as well as any crew action or inaction. A search along the flight path recovered missing aircraft parts and Binstock's body, distributed over an area approximately three miles long and half a mile wide.
The body showed pronounced effects of the fall and marked mutilation of the left hand, with finger ends missing. His coat was cut and perforated in the left arm and breast area, consistent with a blasting cap explosion.
Examination of the fuselage revealed a generally rectangular opening of about 40 square feet, approximately 7 by 6 feet. Partial reassembly of the damaged parts showed conclusively that the explosion was centered on the washbasin shelf along the outer wall of the lavatory, with the violence of the blast decreasing in all directions from the shelf. There was no evidence of metal fatigue.
Chemical analysis of smudge found on the damaged parts positively identified the explosive as dynamite. Investigators found a small copper fragment in the cabin lining with a chemical composition consistent with a blasting cap shell. Inside the lavatory toilet, they discovered an unexploded blasting cap, burned paper matches, and pieces of burned paper.
Investigation revealed that Binstock had procured dynamite and blasting caps several weeks before the incident. The Board noted that the burned matches and paper in the toilet made it evident that previous attempts to detonate the blasting cap had been made before it was successful. The Board concluded that the dynamite was intentionally detonated by Binstock, whose left hand was in close proximity to the explosive at the time of detonation.
### Probable cause
The Board determines that the probable cause of this accident was the act of a passenger in exploding dynamite in flight.