Loads of us have been there and done that with respect to excessive working hours but with experience comes common sense. ie I'm knackered now get lost I need a break! Not many will argue. Last away job I did was up 20hours (working 15), told base that I would be back in about 6 hours but noted a tone of sarcasim or similar in their voice. So, said I understand where you're coming from, 6 hours would be pushing it a bit, see you in8 hours. No response, got my rest, got job done, had beer in town after!