I thought the night training was not deemed strictly necessary
since USAAF made only day-bombing.

That is an incorrect statement. Although by percentage they made up only a
small part of the war effort, US bomber units did occasionally fly at night.
Think about how short the daylight hours are over Northern Europe - "day"
mission or not, if its a 10 hour mission, at least some of it is going to be
past 'pink time'.

v/r
Gordon
====(A+C====
USN SAR

Its always better to lose -an- engine, not -the- engine.