The Challenges of Northern Flight
Harold describes the challenges of flying in the north, particularly in the colder months. Ice fog was prevalent and often obscured most of the ground, so flying by sight was next to impossible at times. The standard magnetic compass was useless that far north, so they had to use an astrocompasses and direction finding gyros. Problems with the astrocompass and gyros were common as well, however, but experience led to developing ways around these problems.