He stated that during the approach and the beginning of his landing run, he had no difficulty compensating for the cross-wind condition and preventing drift; that only after he had lost speed and used an appreciable amount of runway did the plane encounter the sustained gust of great strength which forced him off the runway and onto the wet clay field. It appears that long familiarity with difficult conditions encountered along their regular run has accustomed Northwest's personnel to accept as normal, conditions which elsewhere might be considered marginal. Prior to this accident there were no definite limitations as to wind velocities in which a landing could be made.[1] Subsequent to the accident a conference was held by the Civil Aeronautics Administration air carrier inspectors of the Third Region and Northwest personnel, and following cross-wind landing limitations were issued: (1) When the wind is 0° to 30° off the center line the runway normal operations may be conducted. (2) When the wind is 30° to 60° off the center line of the runway the maximum velocity will be 25 m.p.h. (3) When the wind is 60° to 90° off the center line of the runway the maximum velocity will be 15 m.p.h. These limitations have been set up for normal operations into an airport with only one runway available.
It appears that Northwest's Bismarck radio operator might have been more alert and referred to proper authority the first officer's inquiry as to the availability of the northeast-southwest runway. This runway had been surfaced and rolled the day before, and was awaiting official
- ↑ The manufacturer's Handbook of Instructions for operation of the model DC-3 status the following cross-wind landings: "It is not advisable to attempt to land this airplane in cross winds of 20 m.p.h or more, with the direction of landing more than 10 degrees out of the wind."
