One of my friends has a DH who is a fly in, fly out. They use a calendar so she can see when Daddy will be at work, or at home. She says this helps by giving a timeframe rather than just saying 'he'll be back' which I guess is like saying they'll be back after a sleep etc. The calendar is on the fridge and is month by month with clearly coloured which days Daddys is away so DD can see (I have seen it on the fridge when I have been over at her house). This seems to really help as they can talk about Daddy and when he's coming back, that is OK to miss him, acknowledging this feeling, whilst also being positive about when he will be back. Hope this info helps