Page:CAB Accident Report, Northwest Airlines Flight 5.pdf/5

This page has been proofread, but needs to be validated.

- 4 -

The terminal forecast for Fargo predicted low ceilings of from 200 to 400 feet during the early part of the period covered by the forecast but lifting to 600 to 1200 feet about midnight and to about 1500 by 5 a.m. Visibility was forecast to be from 2 to 4 miles, improving to 6 or more by 1:30 a.m.

In addition, Captain Bates discussed the weather conditions over his proposed route with Captain DeLong of Northwest's Trip 2, who had arrived in Minneapolis while Captain Bates was preparing his flight plan. Captain DeLong stated that he had encountered light ice at 7000 feet above sea level over Fargo and had increased his altitude to 9000 feet above sea level in order to avoid it. Therefore, according to the testimony of Captain Bates and the Minneapolis dispatcher, they planned the flight to operate at lower altitudes than usual in order to avoid the possibility of icing conditions. The flight plan for the trip provided for operation between Minneapolis and Alexandria (about 100 miles southeast of Fargo) at 2500 feet above sea level and the remainder of the flight to Fargo at 2700 feet above sea level. The altitude usually flown along this route, westbound, is 4000 to 6000 feet above sea level.

Another problem involved in the planning of the trip resulted from the fact that the weather conditions reported from Fargo at the time the trip was being planned, were well below the company minimums for that point, i.e., 600 feet ceiling and one mile visibility. References to the reported weather observations from the United States Weather Bureau Station at Fargo indicated that for several hours the ceiling at Fargo had been reported as 100 feet with visibility of half a mile. It had improved, however, until about 11:30 the weather was reported as 300 feet ceiling with 2 miles visibility.

In view of this improvement in weather conditions at Fargo and the indication in the Weather Bureau forecast that ceiling and visibility conditions would continue to improve, Captain Bates and the Minneapolis dispatcher agreed that it might be possible for the trip to land at Fargo. Because of the uncertainty as to whether the weather at Fargo would improve sufficiently to allow the trip to land, it was cleared by the Minneapolis dispatcher to land at Fargo upon condition that weather conditions would permit. The trip was also cleared to land at Bismarck, North Dakota, a stop not usually scheduled on Trip 5, in order that necessary arrangements could be made to provide for Fargo passengers and cargo in the event that no landing could be made at the latter place. The alternate designated for Fargo was Bismarck and the alternate designated for Bismarck was Dickinson, North Dakota. At the time the trip was being planned the ceiling at Bismarck was reported at 1400 to 1600 feet with unlimited visibility, while the reports for Dickinson indicated a ceiling of 800 to 900 feet and 7 miles visibility. The terminal forecast for Bismarck predicted an overcast at 1000 to 2000 feet and visibility greater than 6 miles.

The trip took off from Minneapolis for Fargo at 12:13 a.m. with 620 gallons of fuel, 44 gallons of oil, 12 passengers, a crew of 3, and certain cargo on board. The total weight of the airplane at the time of take-off was 25,008 pounds, and thus within the provisional weight[1]. From the evidence it appears that the airplane was loaded so that the center of gravity was well within the limitations prescribed by the Civil Aeronautics Administration.

After leaving Minneapolis Trip 5 proceeded toward Fargo on instruments at the assigned altitudes. According to Contain Bates' testimony, he anticipated ice constantly during the20635

  1. See Footnote 2, page 3. It was anticipated that approximately 135 gallons of gasoline would be consumed between Minneapolis and Fargo, thus reducing the total weight of the aircraft at the time of the anticipated landing by 810 pounds. The airplane would therefore be brought well within the standard weight by the time it reached Fargo.