Speaking as an ex-military civvy, how did people ever come up with logging chock-to-chock in their logbooks? It's not a very accurate way to record 'flying' time!
I understand the need to record engine time, but what is the relevance of chock-to-chock on a 30min transit with, say, a long hold at the departure airfield. You could end up with over an hour in the logbook!