What information was recorded in Dahl's log book during flight school?

The log book maintained during flight school primarily served as a comprehensive record of Dahl's flying experiences, detailing every flight undertaken and the specific aircraft he piloted. This meticulous documentation is crucial for evaluating a pilot's training progression, ensuring that all necessary flight hours and experience with different aircraft types are formally acknowledged.

In contrast, while the names of instructors, passenger lists, and weather conditions are significant aspects of a pilot's experience, they are secondary to the primary purpose of the log book, which is to note the details of each flight itself. Thus, the emphasis on logging aircraft details and flight records proves essential for certification and flight safety, making it the correct choice in this context.