Cause of 1955 Boulevard Pk. plane crash revealed
Tue, 06/11/2013
By Harland Eastwood
SPECIAL TO THE HIGHLINE TIMES
Here’s the conclusion of our story about the DC-4 military transport plane N-88852 that crashed near Boulevard Park in 1955:
What really happened? The editor recalls that speculation about the cause of the crash was plentiful in the days and weeks following the crash. It seems as if everyone you talked to had an idea of what had happened, but that no one really knew. Many of these theories have persisted to this day. One of the more prevalent theories advanced was overloading.
While doing research on this story the editor interviewed Merrill Kleinmann who was renting a room from Sam and Florence Montgomery at the time of the crash. Near the end of my interview, Mr. Kleinmann presented me with a copy of the Accident Investigation Report conducted by the Civil Aeronautics Board. This 19-page report was extremely detailed, thorough, and covered every aspect of the accident.
The following are portions of that report.
Civil Aeronautics Board accident investigation report: The Accident at approximately midnight, November 17, 1955, a Douglas C-54-DC, (DC-4), N88852, operated by Peninsular Air Transport, crashed in a residential area of Seattle, Washington. The accident occurred immediately following takeoff from Boeing Field. Of the 74 persons aboard, 28, including a third pilot, were fatally injured. The remaining 46, including other crew members, received injuries of varying degrees. Although there were no injuries to persons on the ground, the accident caused substantial property damage. The major portion of the aircraft was destroyed by impact and fire.
History of flight: Peninsular Air Transport Common Carriage Flight 17K was scheduled to originate at Boeing Field and terminate at Newark, New Jersey, with intermediate refueling stops. The assigned crew consisted of Captain W. J. McDougall, First Officer Fred C. Hall, and steward J. O. Adams. The third pilot, Edward McGrath, deadheading to Miami, Florida, occupied the jump seat with no crew duties.
The flight, scheduled to depart at 8:30 p.m., was delayed because of heavy snowfall during the afternoon and early evening of November 17, which delayed the aircraft before departure.
At 11:32 p.m. the flight taxied to runway 13, holding off the runway waiting its turn behind other flights to take off. During this time the crew completed pre-takeoff checks and received an IFR (Instrument Flight Rules) clearance. This, in part, instructed them to turn right after takeoff and climb on a northwest course of the Seattle Range to 5,000 feet m.s.l. (mean sea level.)
The takeoff was started at 11:58 p.m. and appeared normal as the landing gear retracted and a right turn was begun. When approximately 300-400 feet above the ground the first reduction of power, from takeoff to normal rated power, was made about five of the 15 degrees of flaps extended, were retracted. At this time the No. 4 propeller surged and engine r.p.m. increased to about 2,800. Unable to reduce the r.p.m. of No. 4 by reducing its power, an attempt was made to feather the propeller; this was also unsuccessful.
As the aircraft then began to descend, takeoff power was reapplied to Nos. 1, 2, and 3 engines and the power from No. 4 was further reduced. This action did not reduce the r.p.m. of No. 4 which surged again and increased to more than 3,000. The aircraft veered to the right and continued to descend.
Realizing that a crash-landing was imminent, Captain McDougall reduced the airspeed until the aircraft was nearly stalled and applied full power to all four engines. The aircraft continued to settle. It then struck a telephone pole and several trees before crash landing in a nose–high attitude.
Fire and rescue equipment were dispatched to the scene from both Seattle Fire Department and the Seattle-Tacoma Airport. The units arrived promptly and gave first aid to the survivors. Fire which followed the crash was quickly extinguished but not before extensive property was burned and the aircraft nearly consumed.
Investigation: The accident scene was located approximately 2 1/2 miles from and 300 feet higher than the take-off position of the flight. Evidence showed that the aircraft was banked to the right when it initially struck the telephone pole with its right wing and horizontal stabilizer. Continuing along the impact heading of 210 degrees it came to rest approximately 650 feet beyond the pole.
Along this path the aircraft struck several buildings, trees, and another pole, causing separation of both wings and tail and severe damage to the fuselage.
The fire, which broke out after final impact, consumed major portions of the structure. Examination of the remaining portions of the wings, fuselage, and tail disclosed no evidence that indicated structural failure or malfunction prior to impact. Both pilots stated they had experienced no difficulty except that associated with the No. 4 engine and propeller.
The four power plants, including their accessories, were located within a relatively small area. Each had been separated from its mount and its nose case torn off. All had been exposed to the resultant fire, which consumed their rear magnesium cases.
The propellers were found attached to their respective propeller shafts and Nos. 1 and 4 were not damaged by fire. Teardown inspection of Nos. 1, 2, and 3 engines and propellers disclosed no evidence to indicate they were factors in the accident.
No. 4 propeller, attached to the engine nose section, was located about 25 feet from the main wreckage. There was oil covering its barrel, the face sides of all propeller blades, and the engine nose section.
Examination disclosed that the propeller dome retaining nut protruded approximately one-eighth of an inch above the barrel dome bore and the safety cap screw was pressed against the corner of the safety recess. The lock screw was safetied.
The screw was removed and its examination showed no evidence of binding or mutilation. After the nut and barrel were marked to show their original positions, a check was made for tightness. The result showed the nut could be moved with comparative ease with a small drift and hammer for at least 4 1/2 inches of tightening direction.
The nut was then unscrewed and the dome removed to check the propeller blade pitch settings as indicated by the cam gear position. This revealed the cam gear lug was against the low pitch stop, or the normal low pitch blade angle setting. The blade segment gears were marked to show their positions in relationship to each other and to the cam gear.
The propeller assembly was then further disassembled and examined, after which it was removed from the accident scene for continued examination and testing.
With the exception of the findings and probable cause contained in the investigation, the remainder of the report has been omitted due to its considerable length and the abundance of technical terms.
Findings:
On the basis of the available evidence the Board finds that:
1. The carrier, the aircraft, and the crew were currently certificated.
2. The aircraft was loaded within allowable weight limits and the load was properly distributed with respect to the center of gravity of the aircraft.
3. Weather conditions at takeoff were above minimums with respect to ceiling and visibility.
4. There was no snow or ice on the aircraft when it took off.
5. During the first power reduction the No. 4 engine r.p.m. fluctuated, became uncontrollable, and shortly thereafter increased to more than 3,000.
6. Efforts to reduce the r.p.m. and feather the malfunctioning propeller were unsuccessful.
7. The propeller dome retaining nut was not tightened sufficiently, permitting oil to leak around the dome seal.
8. The leaking oil resulted in a lack of oil for reducing the r.p.m. or feathering the No. 4 propeller.
9. Poor maintenance procedures, omissions during maintenance work performed by Seattle Aircraft Repair, Inc.
10. Improper indexing of the No. 4 propeller blades occurred during work at Seattle.
11. Propeller drag from the over-speeding propeller greatly increased by the incorrect indexing of the blades made flight difficult if not impossible.
12. The aircraft was unairworthy following the Seattle maintenance work.
Probable cause:
The board determines that the probable cause of this accident was the excessively high drag resulting from the improperly indexed propeller blades and the inability to feather. These conditions were the result of a series of maintenance errors and omissions. The Civil Aeronautics Board did not release their report until April 30, 1956, some five months after the accident. It is not known whether the results of this investigation were made public or not, but it is probably safe to conclude that many of those who remember the crash were not aware of the real reasons that Peninsular Air Transport’s N-88852 slowly fell from the sky at Boulevard Park on the night of November 17, 1955.
This is certainly true for your editor. I suspect that many of our readers will also identify with me when I say, “After all these years I never knew what really happened, but now I do.”
The editor wishes to thank all those who contacted the editor, provided information and or sent photographs pertaining to this story. The list is long and it is hoped that no one has been left out. They are Merrill Kleinmann, Judy Billings Reano, Greg Rathbone, Bill Starr, Dave Curts, Chuck Sting, Janet Kraft Pierson, Joe Gaunt, Larry Watters, Bea Kuenstle, Alice Takashima, Reed Anderson, Leona Strickler Hardin, Chris Thorsen and Eric Thorsen. Harland Eastwood cam be reached care of Ken Robinson at kenr@robinsonnews.com.