Page:CAB Accident Report, Northwest Airlines Flight 5.pdf/15

 cate of public convenience and necessity and an air carrier operating certificate authorizing it to conduct the flight.

3.

Captain Bates and First Officer Orsgard were physically qualified and held proper certificates of competency to operate as air carrier pilots over the subject route.

4.

Aircraft NC 21712 was currently certificated as airworthy at the time of the accident.

5.

Trip 5 was cleared in accordance with company procedure from Minneapolis, Minnesota, to Bismarck, North Dakota, with clearance to land at Fargo, North Dakota, if weather conditions there would permit. The alternate designated for Fargo was Bismarck and the alternate designated for Bismarck was Dickinson, North Dakota.

6.

At the time of departure from Minneapolis, Minnesota, and at the time of the accident, the gross weight of the airplane did not exceed the permissible gross weight and its load was properly distributed.

7.

At the tire of departure from Minneapolis, Minnesota, the aircraft carried sufficient fuel to permit flight at normal cruising power to Fargo, North Dakota, or to Bismarck, North Dakota, and thereafter to permit it to proceed to its alternate airport with sufficient fuel still remaining in the tanks for about 3 hours of flight.

8.

Weather forecasts reported the existence of a cold front which had reached Fargo, North Dakota, and was moving eastward. Before Trip 5 departed Minneapolis, the ceiling at Fargo had been reported as varying between 100 and 300 feet. The terminal forecast for Fargo predicted that the ceiling would lift to 600-1200 feet about midnight.

9.

At the time the trip was being planned the ceiling at Bismarck, North Dakota, was reported as 1400 to 1600 feet with unlimited visibility. The terminal forecast for Bismarck predicted an overcast at 1000 to 2000 feet and visibility greater than 6 miles.

10.

Trip 5 proceeded normally from Minneapolis, Minnesota, to Fargo, North Dakota, accumulating light ice on the airplane upon approaching that point. Upon the arrival of Trip 5 in the vicinity of Fargo, North Dakota, the ceiling remained about 100 feet below the prescribed minimum for landing.

11.

After arriving in the vicinity of Fargo, North Dakota, and descending from cruising level to about 2000 feet above sea level, it was noticed that the airplane was taking on considerably more ice and the de-icer boots were turned on.

12

.Captain Bates made a normal descent to approximately 600 feet above the ground, at which point, while still on instruments, he leveled out. Immediately the airplane "started to act peculiarly", and Captain Bates applied full power. A severe buffeting condition commenced and the airplane began an uncontrolled descent, continuing until it struck the ground in an almost level attitude with a forward speed of approximately 90 m. p. h.

13.

There was no structural or power plant failure prior to the accident.

14.

The engines were functioning normally at the time the aircraft struck the ground.

15.

While icing conditions existed over the route, the dispatcher failed to recognize the seriousness of that condition at the base of the clouds in the Fargo area and as a re