FOR IMMEDIATE USE

FOR IMMEDIATE USE January 9, 1935

DEPARTMENT OF COMMERCE

BUREAU OF AIR COMMERCE

Washington

7237-//

STATEMENT OF PROBABLE CAUSE CONCERNING AN AIRCRAFT ACCIDENT WHICH OCCURRED TO A PLANE OF NORTHWEST AIRLINES ON AUGUST 7, 1934 AT MILWAUKEE, WISCONSIN

To the Secretary of Commerce.

On August 7, 1934 at about 11.tif:56 p.m., at Milwaukee, Wisconsin, an airplane of United States registry, piloted by a licensed airman, while being operated in scheduled flight, carrying passengers and, by special request, one pouch of mail, crashed with resultant serious injuring to the crew and several passengers and the complete destruction of the aircraft.

The plane, a Lockheed Electra, modal 10-M bearing Department of Commerce license number NC-l443, was being operated between St. Paul, Minnesota, and Chicago, Illinois by Northwest Airlines, Incorporated. The pilot, Joseph Ohrbeck, held Department of Commerce transport pilot's license No. 2233 and a scheduled air transport rating. The co-pilot, John Woodhead, held Department of Commerce transport pilot's license No, 22344. The pay passengers carried were George Merkos, Frank Cooper, Donald Couture Les Edge, William R. P. Clark and A. G. Callahan. Another passenger, G. Boe, was an employee of the company.

This trip was scheduled to leave at 8 p.m. However, due to delay, the actual takeoff from St. Paul was made at 9.25 p.m. One stop was made at Minneapolis and the plane arrived at Milwaukee, Wisconsin, at 11.tif:45 p.m. with a total flying tine of 2 hours.

The pilot states that the plane's two fuel tonics were filled to capacity (100 gal. each) at the start of the flight. For the first 1-1/4 hours of flying the selector valve was set so that fuel could be used from both tanks, simultaneously. At the end of this period however, his gauges indicated a full left tank and a 5/8-full right tank. He then changed the selector valve to left tonic only and the remaining hour of flying was done on this tank. After landing at Milwaukee, his fuel gauges indicated a 5/8 full right tank and a 1/2 full left tank.

The takeoff from Milwaukee was made using the left fuel tank only. When at an altitude of about twenty feet, the fuel warning lights came on and the left engine stopped. The pilot immediately switched the fuel valve to feed from both tanks and the co-pilot used the wobble pump. The plane settled to the ground with enough force to blow the right tire and break the right hub and wheel structure. At the time of impact, the left engine started again and, under power of beta engines, the plane rose to an altitude of fifty to seventy-five feet. At this time, the right engine stopped, throwing the plane slightly to the right. The pilot immediately switched back, to the left tank and the co-pilot continued to use the wobble pump but did not feel that any fuel was getting through. As the plane started to settle, the left engine slowly lost speed and the plane slid off on the right wing and nose, cartwheeling some seventy-five feet and coming to rest in an upright position.

From our investigation and public hearing, it appears that the airplane had just recently been received from the factory and had been put into service without anyone haying a definite knowledge of the amount of fuel it consumed per hour of normal flying. This trip was Pilot Ohrbeck's first flight in this particular plane, and he took off on the general assumption that its fuel consumption was about forty-three gallons per hour. Although the fuel gauge readings after 1 1/4 hours of flying (right tank 5/8 full; left tank full) indicated that something wasn't just right when fuel should have been draining from both tanks, the gauge readings after landing at Milwaukee (right tank 5/8 full; left tank 1/2 full) indicated a fuel consumption reasonably close to the general assumption of 43 gal. per hour.

However, an inspection of the fuel system after the accident disclosed that the right tank contained from fifty to sixty gallons of fuel and that the feed lines from this tank were full. The left tank was found to contain about one gallon and the feed lines were dry. Both carburetors contained a few drops of fuel. This indicated an actual fuel consumption of approximately 63 gal. per hour and although his left gauge indicated a tank one-half full, actually the tank was practically empty at time of takeoff from Milwaukee.

It is the opinion of the Accident Board that the probable causes of this accident were

Failure of the Supervisory Personnel to definitely determine the actual fuel consumption of a new airplane before placing it in scheduled operation.

Failure of the fuel gauge on the left tank to function accurately.

Pilot error for failing to attempt to use the right fuel tank after the instrument board warning light had indicated that the task which he was using was about empty.

Respectfully submitted,

Eugene L. Vidal

Director of Air Commerce

The plane was held on the ground at St. Joseph from 7.tif:10 p.m. until 10.tif:27 p.m., pending more favorable weather reports ahead. At 10.tif:15 p.m., after a study of available reports from Omaha and Tarkio, a point approximately midway between Kansas City and Omaha, Pilot Bontrager decided to take off, check conditions along the route and if too unfavorable, return to St. Joseph. The actual take off from St. Joseph was made at about 10.tif:27 p.m. and the accident occurred approximately fourteen minutes later.

Our investigation indicates that Pilot Bontrager was proceeding at a low altitude, doing visual beacon to beacon contact flying. Shortly after passing No. 6 beacon on the Kansas City-Omaha route, he suddenly encountered a torrential downpour of rain and attempted to make a turn to return to St. Joseph. At this point it can be seen where the plane first struck a group of trees and then collided head-on into a road bank while still waking the turn. Fire followed immediately. The ground at this point is considerably higher than at St. Joseph and an examination of the wreckage and the adjacent territory suggests strongly that, due to the combination of darkness and blinding rain, the pilot had no idea of his nearness to the ground. Unquestionably, everyone on board was killed by the force of impact and a watch recovered from the wreckage fixed the time of the accident at 10.tif:41 p.m.

The Board finds that the probable causes of this accident were.tif:

Dangerous and unusual weather conditions encountered.

That the pilot committed an error of judgment in taking off in the fact of dangerous and threatening weather, about which he did not have sufficient information.

That the ground control of operations was inadequate to meet the emergency created by this unusual weather.

Respectfully submitted,

Eugene L. Vidal,

Director of Air Commerce