Originally Posted by
DylanFan
I've done a little research and the simplest explanation I can come up with is outlined in a couple of Chief Counsel Opinions from 2007 and 2005 (links below).
http://www.faa.gov/about/office_org/...07/schwarz.pdf
http://www.faa.gov/about/office_org/...ill135267f.DOC
They both state that in order for time to be counted as "rest," it has to have three criteria. Rest must be 1) continuous, 2) determined prospectively, (i.e. known in advance) and 3) free from all restraint by the certificate holder, including freedom from present responsibility from work should the occasion arise.
Duty time and rest time is such a ridiculous mess which is purposefully set up in such a way that it leaves the FAA option to violate should the need arise. I doubt that a violation would ever come about unless something happened to bring it on, such as an accident or incident, but it could. Get on the wrong side of your POI and you may have some issues if you are operating based on principles located in the "grey areas".
At our company, we make every attempt to follow the guidleines to the "t" and err to the conservative side in the grey areas. For example we are only assigned to be on-call for 10 hour periods thoughout the day, after which we are assigned rest for at least nine hours so that we are legal for another full duty period the next day. (10 hours rest for ops under 135.267) That on-call period is "duty time" as we are not free from the constraints of the company and it is not prospectively identified as rest. If I get a call on hour nine of my on-call period, then I can fly, however I only have six hours of duty remaining unless I am on reduced from the rest period before...in which case I would have less.