Is a pilot's salary forbidden, and will he die in great sin if he works in aviation, a field in which matters displeasing to Allah may occur?

The profession of a pilot is permissible, and his earnings are lawful. Any sins associated with it are attributed to the individual, but they do not render the earnings unlawful. This is similar to any employee whose job is permissible but who commits sins; his earnings are lawful for him, and the sin falls upon him for committing the transgressions, not because of his profession. However, if the benefit itself is forbidden, such as the work of an accountant dealing with usury or a bartender serving alcohol, then his earnings are not permissible.