WOW.
Your father in law was flying over Germany without very good air support cover at that time.
He was likely a skilled pilot but also very lucky either a Messerschmidt didn't get him or shot down by the anti-aircraft guns.
Glad he made it.. Anytime a serviceman comes home from a war its a great day.. Far too many have not come back. we owe every one a huge debt of gratitude that never can be repaid..