Flight crew originally scheduled to do a three sector day, reporting for duty at 10:45Z with planned off-duty time of 20:25Z.
However, prior to leaving home, Crewing call (08:30Z) to say that they're standing-down the crew and instead putting them on standby from 16:00Z until 22:00Z (with their hope being that they'll operate the last of the aforementioned three sectors - which happens to be a very short sector. i.e. less than 1hr).
Crewing call again at 14:10Z (err, but the standby period yet hasn't started yet ?!) now telling the crew to report at 17:55Z - for a two sector trip that will see them off-duty (down-route) at 04:45Z and that these two sectors will now be operated by a 'heavy crew' (i.e. three pilots in the flight-deck - due to the fact that the 2nd of the sectors is more than seven hours long, wherein having the extra person allows the FDP to remain that from either Table A or B as appropriate).
So the questions are:
- Is it legal ? and if so....
- What time would ones newly revised duty period start ?
The airline is a UK JAR operator that's having a bad day due to some tech aircraft.