We follow 91, 91k, or 135 regs depending what kind of flight it is (ferry, owner, marquis). Some fleets get the show at legal (10 hours of rest) brief more than others (notably the X) but in the Ultra it seems to be a rarity for me. Most of my overnights are 12-14 hours with the occasional 18 hour thrown in for good measure. If you are at HPN or PBI you can very well expect your airplane to be not where you left it and probably not in the same time zone either but if you are out in the boonies somewhere it will likely still be there. They will generally ferry in another crew with a plane if the owner decides they want to go before our briefed time. That way they dont have to airline one crew in to get the plane and then airline another crew out. Its not like it takes a long time to get a replacement airplane. The numbers I heard were that we can have a recovery aircraft in place almost anywhere in the US in 1.5 hours.