What specific damage was done to Dahl's plane?

The specific damage to Dahl's plane was a round hole in the propeller blade. This detail is significant because it highlights the severity of the situation he encountered during his flight. Propeller damage can drastically affect the aircraft's performance and control, making it a critical issue for any pilot. In Dahl's account, he describes the moment when the plane was struck, emphasizing how such an unexpected event could lead to perilous circumstances in the air. This moment is pivotal in the narrative as it underscored the risks involved in flying, particularly during wartime, and adds to the tension and drama of his experiences. The other options mention different potential issues that could arise in aviation, but none reflect the specific incident described in Dahl's account.