In his book, Steuart Campbell suggested that two errors by the pilots; failure to climb to a safe altitude upon entering cloud, and a navigational error made in the poor visibility (mistaking a fog signal station for a lighthouse), together caused the crash. The Board of Inquiry had identified that several factors may have sufficiently distracted the crew from turning away from the Mull, and upon entering cloud, failed to carry out the correct procedure for an emergency climb in a timely manner.