On October 19, 1959, four crew members are killed and four passengers are injured when a new Boeing 707 jet transport on a demonstration flight for Braniff International Airways crash-lands in the North Fork Stillaguamish River near the small community of Oso, 12 miles northeast of Arlington in Snohomish County. An investigation by the Civil Aeronautics Board will determine the accident was the result of a violent Dutch Roll maneuver during the flight which caused structural failures and the loss of three of the plane's four jet engines.
An Ill-Fated Training Flight
The Boeing 707 was the first truly successful commercial jet transport. It was a big aircraft for its time -- 144 feet, six inches long with a wing span of 130 feet, 10 inches and weighing 120 tons. It was powered by four 13,500-pound thrust Pratt & Whitney JT3C-6 turbojet engines. At a cruising speed of 600 mph, the plane had a range of 3,000 miles with accommodations for up to 181 passengers. Between 1957 and 1978, the Boeing Company produced 725 Model 707s and custom-designed variants for commercial use.
At 2:51 p.m. on Monday, October 19, 1959, a Boeing 707-227 jet airliner, registration No. N7071, departed Boeing Field (now King County International Airport) for a demonstration and acceptance flight prior to the aircraft being delivered to Braniff International Airways, Inc. The estimated flying time for this training mission was four hours and 15 minutes.
The crew for the flight consisted of Russell H. Baum, Boeing test pilot/instructor; John A Berke and Manliff F. "Frank" Staley, Braniff pilots; and George C. Hagen, Boeing flight engineer. Listed as passengers were William J. Allsopp, Boeing test pilot; William H. Huebner Jr., Federal Aviation Administration Air Carrier Operations Inspector; Albert C Krause, Braniff flight engineer; and Fred Symmank, Braniff maintenance instructor. During the flight all eight men were present on the flight deck.
After takeoff, Baum demonstrated several maneuvers, which were duplicated by Captain Berke, who was making his first flight in a Boeing 707. Baum initiated a series of Dutch Rolls at cruising speed in clean configuration, i.e., with flaps retracted, to demonstrate the proper method for recovery. (A Dutch Roll is an alternating yawing and rolling motion, characteristic of large swept-wing aircraft, and can be caused by air turbulence or lateral over-control.) Braniff Captain Berke then executed several satisfactory Dutch Roll recoveries from the left-hand (pilot's) seat. Baum then slowed the aircraft to 155 knots and lowered the flaps 40 degrees and had Captain Berke make a series of recoveries from this configuration. Afterwards, they traded positions so that Berke could practice recoveries from the right-hand seat.
Pushed Too Far
During these maneuvers, Baum allowed the 707 to bank more than 25 degrees, in excess of the maximum limitation imposed by the Boeing safety manual. Allsopp cautioned Baum about banking too steeply during the Dutch Roll maneuver but Baum ignored the warning. Baum then initiated another Dutch Roll in which the aircraft's angle-of-bank reached from 40 to 60 degrees. Captain Berke allowed the plane to complete several oscillations and then began recovery. Due to his misapplication of the controls, however, the plane rolled to the right past 90 degrees, then abruptly to the left and went into a spin.
The emergency took place over north Snohomish County at an altitude of 12,000 feet. Baum quickly took the controls and restored the aircraft to level flight, but three of the plane's four jet engines had been torn away during the uncontrolled gyrations. The areas where the engine pylons had been attached to the wings were on fire and the plane was losing altitude.
After a quick damage assessment, the four passengers moved to the tail section and took positions for a wheels-up emergency landing. Unable to reach the airport at Arlington or Paine Air Force Base at Everett, Baum selected a large open pasture between the Arlington-Darrington Highway (State Route 530) and the North Fork Stillaguamish River, approximately one mile west of the small farming community of Oso. In order to keep the wings level, Baum had to prematurely shut down the remaining jet engine. During the dead-stick landing, the crippled 707 clipped a grove of tall trees just shy of the pasture, plunged abruptly onto the bank of the Stillaguamish River, and exploded.
The impact and an ensuing fire completely destroyed the forward section of the fuselage, and wreckage was strewn over several acres. The tail section broke away just aft of the wings and landed crosswise in the middle of the river. Although badly damaged, the empennage (rear section) of the airplane remained intact, and its four occupants survived the mishap without serious injuries. They crawled out of the wreckage into the water and were helped up the riverbank by two men working nearby.
The Boeing 707 crash-landed on the farm of Anton and Ada Ostler. The couple ran down to the river when the accident happened but were unable to approach the wreckage because of the raging fire and recurrent explosions. While Anton stood watch, Ada Ostler hastened to the farmhouse and telephoned the Snohomish County Sheriff's Department. The call brought an immediate response from the state patrol, police and fire departments, ambulance services, and volunteers from surrounding communities. First to reach the scene was a detachment of sailors with fire-fighting equipment from the Jim Creek Naval Radio Station, six miles south of Oso. They brought the fire under control and kept it from spreading until additional help arrived.
The survivors, suffering from shock and hypothermia, were rushed by ambulance to Arlington General Hospital. Search parties recovered the bodies of the four victims, burned almost beyond recognition, during the night. Three were found in the smoldering wreckage of the cockpit and the fourth was pulled from the river. Their remains were transported to the Snohomish County Medical Examiner's Office in Everett for official identification and issuance of death certificates.
The following day, one jet engine was found in woodlands approximately one mile northwest of the crash site. A second engine was found one-half mile beyond that in the same direction. And on Monday, October 26, 1959, a helicopter pilot spotted the third engine in the same general area. An examination revealed the three power plants, with major portions of their pylons still attached, had been wrenched from the wings during the exceptionally violent Dutch Roll maneuver. The fourth engine remained attached to the plane until the crash landing. None showed evidence of fire or malfunction prior to impact with the ground.
The Bonnie-Watson Mortuary of Seattle shipped the remains of the two Braniff Airways pilots to their families in Dallas, Texas, for funeral services and interment. Captain Berke was buried at Grove Hill Memorial Park and Captain Staley at Restland Memorial Park. A funeral service for Captain Baum was held at Sunset Hills Funeral Home, 1215 145th Place SE in Bellevue, Washington. His ashes were interred in the Garden of Devotion columbarium at Sunset Hills Memorial Park. Stokes Mortuary of Renton sent the remains of Flight Engineer Hagen to Savannah, Georgia, for burial.
The Civil Aeronautics Board (CAB) was notified of the accident at 6:00 p.m. on Monday, October 19, 1959, and immediately initiated an investigation. The flight recorder, marking time, altitude, attitude, air speed, course, and vertical-gravity forces, was recovered from the wreckage. However, it had not been activated for the demonstration flight. The CAB relied mostly upon expert testimony from the four survivors and witnesses on the ground to tell the story.
On Monday, June 20, 1959, the CAB released its Aircraft Accident Report about the mishap. The board determined that the probable cause of the accident was the structural failures of three of the four engine pylons caused by an improper recovery attempt from a Dutch Roll maneuver that exceeded the angle-of-bank limits specified by the Boeing training manual. In its press release, the CAB said it could find "no valid reason for Mr. Baum's initiating the final Dutch Roll so violently. No training advantage could be gained by conducting these maneuvers at the extreme angles of bank reached. Baum certainly should have been aware of this, and he was admittedly aware of the company's restrictions" ("Instructor Blamed for 707 Crash").
This was the second accident involving a Boeing 707 since the jet transports were put into commercial service with Pan American Airlines in October 1958. The first mishap occurred on Saturday, August 15, 1959, when five crew members were killed on a training flight aboard an American Airlines Boeing 707-123 near the Peconic River Airport at Calverton, New York. According to the CAB Aircraft Accident Report, the crash was caused by "an unintentional rolling maneuver at an altitude too low to permit a complete recovery" ("Accident Investigation Report").
Those killed in the Snohomish County crash were:
Russell Harry Baum, (1927-1959), age 32, Boeing test pilot/flight instructor
John Anton Berke, (1910-1959), age 49, Braniff pilot
George Charles Hagen, (1931-1959), age 28, Boeing flight test analyst
Manliff Franklin Staley, (1916-1959),age 43, Braniff pilot
William J. Allsopp, age 41, Boeing test pilot
William H. Huebner, Jr., age 35, FAA air carrier pperations inspector
Albert C Krause, age 28, Braniff flight engineer
Fred Symmank, age 39, Braniff technical instructor