Page:CAB Accident Report, TWA Flight 3 (January 1942).pdf/17

 The evidence indicates that in preparing a flight plan the practice is to divide the flight into several portions, each of which may include a number of sectors or legs having separate courses, and to enter on the flight plan for each portion a course which represents the average of the courses of the individual sectors. The result is that a course designated on the flight plan is approximately equivalent to a straight line between the extremities of the portion of the flight for which it is entered.

The average magnetic course between Las Vegas and Daggett is about 210 degrees, rather than 218 degrees which was the course designated on the flight plan. The average magnetic course between Boulder City and Daggett, on the other hand, is 218 degrees. In view of the