1950 — Mar 7, Northwest 307 hits flagpole, Twin Cities AP landing, crashes, Minneapolis, MN–15

Compiled by Wayne Blanchard, 8-29-2023, for upload to: http://www.usdeadlyevents.com/

–15  Aviation Safety Network.  Accident Description. Northwest Orient Airlines, 7 Mar 1950.

–15  CAB. AIR. Northwest Airlines, Inc., Minneapolis, Minn., March 7, 1950, p. 2.

–All 13 on NW 307

–Two children in bed in house which was destroyed – girl 10 and brother, 8.[1]

–15  National Fire Protection Assoc. “Large Loss Fires of 1950.” Quarterly, 44/3, Jan 1951, p. 249. 

Narrative Information

Civil Aeronautics Board. Accident Investigation Report:

“The Accident

“Northwest Airlines Flight 307, a Martin 202, aircraft N-93037, crashed 4-3/8 miles west of the Twin Cities Airport,  Minneapolis, Minn., at 2059, March 7, 1950. The 10 passengers and crew of three were killed. The aircraft was completely destroyed…

“History of the Flight

“Flight 307 originated in Washington, D. C., at 1230, March 7, 1950, destined for Winnipeg, Manitoba, Canada. Scheduled intermediate stops included Detroit, Mich., Madison, Wis., Rochester, Minn., and Minneapolis-St Paul. Donald B. Jones was captain, William T. McGuinn, copilot; and Mary Kennedy, stewardess….

“Flight 307 arrived over Rochester at 2023, and because there was light freezing rain, did not land. Twelve minutes later the flight made a routine report to company radio that it was over Stanton which is a radio beacon 30 miles south of the Twin Cities Airport at Minneapolis, and at 2041 contacted Minneapolis Approach Control for landing clearance.

“The tower advised Flight 307 of existing weather conditions. There was a precipitation ceiling of 900 feet, visibility was variable ½ to ¾ of a mile, and the wind was from the north 27 miles per hour with gusts up to 40 miles per hour. The tower informed the flight that there had been two electric power failures at the field, and that if no further communication were received from the tower, it would be in all probability the result of another power failure. The flight was also told that the ILS was serviceable, but that it had not been flight checked….

“Flight 307 was not seen from the tower during its approach, but it was heard to pass overhead at which time the controllers received the call, ‘I have got to get in.’ Clearance was again give to land, following which the flight advised that it would climb to 2,400 feet on the northwest course of the Minneapolis radio range. After a pause, the flight transmitted. ‘We are going in – we are going in.’

“After the aircraft had flown over the field, it was observed flying straight and level 3/8 miles northwest of the airport. A wing was seen to fall. Then, the aircraft was observed to dive almost vertically from an altitude of about 300 feet, and crash into a residence in the city of Minneapolis. Fire, which started immediately after the crash, consumed the house and much of the aircraft wreckage. All of the 13 occupants of the aircraft and two of the occupants of the house were killed.

Investigation

“The main body of the wreckage was located in the basement of the residence into which the aircraft crashed. This home was located 4 3/8 miles northwest of the field….

“A piece of the lower front spar cap from the left wing was found 300 feet north of a tapered steel flagpole which was located at the time of this accident near the entrance of the National Soldiers Cemetery. This pole was 4,180 feet south of the approach end of Runway 35 and 650 feet west of the center line of that runway. The top extended 70 feet above the ground, but it was 126 feet below the low limit line of the glide path. It was well marked by red neon lights, which were functioning at the time of the accident. The pole was eight inches in diameter at the base, and 3-5/8 inches in diameter at the top. Wall thickness was ¼ of an inch. Examination of the pole disclosed that the aluminum paint from two to four feet from the top had been scraped from the south curvature, and that the pole had been bent in an azimuth of 17 degrees true. A large ornamental American eagle which had been mounted on the top was found 20 feet south of the pole’s base while the red neon lights were found 40 feet to the north. It was apparent that Flight 307 had struck the pole during the attempted approach….

“….When the aircraft struck the flagpole it was 128 feet below the ILS glide path, 650 feet west of the center line of the runway, and it was flying a course 17 degrees to the right of the runway heading. From this point it turned left sufficiently to pass over the control tower which was located 1/6 miles north of the flagpole. The aircraft then flew northwesterly 3/8 miles where the left wing section…became totally separated from the aircraft and dropped to the foot of Washburn Park water tower. Then the aircraft progress westerly an additional 3,640 feet before striking the residence located at 1116 West Minnehaha Highway.

“An examination of the actuating mechanism for the landing gear and landing flaps showed that both were retracted at the time of the crash….

“Analysis

It is clear that no aircraft engine failure was involved in this accident since none was indicated by the investigation, and since the aircraft flew six miles after striking the flagpole. It is also indicated that the pilot was not using ILS throughout his landing approach, because wen he struck the flagpole he was 128 feet below the glide path and 650 feet to the left of the center line of the localizer….

“…other pilots were able to complete their landing approaches during the period of the accident by visual reference to the ground, since slant visibility was relatively good.

“Accordingly, it appears reasonable to conclude that the pilot of Flight 307 attempted to complete his landing approach visually, and did not use the ILS. Since the flight struck a flagpole which was clearly marked by red neon obstruction lights, it is also reasonable to conclude that visibility was restricted by blowing snow. It is possible that the propeller blasts from the Boeing 377 raised both the height and density of the snow condition. Then, the pilot without visual or instrument reference to the runway, and while in an area where heavy turbulence had been reported, flew too low and too far to the left, striking the flagpole.

“Probable Cause

“The Board determines that the probable cause of this accident was the attempt to complete a landing approach by visual means during which time visual reference to the ground was lost.

(CAB. AIR. Northwest Airlines, Inc., Minneapolis, Minn., March 7, 1950.)

 Sources

Aviation Safety Network. Accident Description. Northwest Orient Airlines Flight 307, 7 Mar 1950.  Accessed 2/9/2009 at: http://aviation-safety.net/database/record.php?id=19500307-0

Civil Aeronautics Board. Accident Investigation Report. Northwest Airlines, Inc., Minneapolis, Minn., March 7, 1950 (File No. 1-0031). Washington, DC: CAB, 12-4-1950. Accessed 8-29-2023 at: dot_33389_DS1.pdf

National Fire Protection Association. “Large Loss Fires of 1950.” The Quarterly, Vol. 44, No. 3, January 1951, p. 249. 

The News, Frederick,. MD. “Cemetery Flagpole Caused Plane Crash.” 3-9-1950. Accessed at:  http://www.newspaperarchive.com/freepdfviewer.aspx?img=14372685

[1] The News, Frederick. MD, “Cemetery Flagpole Caused Plane Crash.” March 9, 1950.

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