This earlies/lates nonsense. It's a new whizz-bang idea created from the LOCo's in very recent years. There is too short a history to say it is scientifically proven to be better etc. etc. I've worked under many different FTL's in long & short-haul. Nothing is perfect, and it sure ain't one size fits all, but that is what is forced upon crews. There is a 'scientifically proven' characteristic for people called owls & larks. Put them in the correct phase and they function fine: put them out of phase and they are below par: put them out of phase for 5 consecutive days and I leave you to draw conclusions. In such a safety related environment being out of phase for days is plain stupid if there is a better alternative. One day, OK, but 5 days...? Yet, when rostering was requested for continuous earlies or lates to suit your phase it was refused for everyone. One size fits all or you are in the wrong job. What utter bollox. For every scientifically proven Yes there will be another No. Ask the RYR pilots for their opinion about the NASA expert and their rosters. Computers are wonderful at what they were designed for, but they were not designed to be better than individual human experience of events.
The whole thing is not driven by science it is driven by greed of the airlines and the various XAA's are in their pockets. It is fact that FTL's have increased as the performance and endurance of a/c have increased. That is driven by productivity = profit and not human performance, and has been allowed by the various XAA's. It is also fact that human mistakes have been mitigated by technology, thus it is deemed an acceptable risk to allow the human in control to be depleted because the technological automatic systems and back-ups will compensate. You can go to sleep over the Pacific and the autopilot will keep you on track and level until you hopefully wake up before TOD. Not so years ago. With the advent of a superior 'George' the human can take a back seat and be knackered because good old Electron George will save the day. (What was the name of the computer on board in 2001 Space Odyssey? He was way ahead of his time, but his time is nigh). I've worked in non-union charter airlines where we had a night Africa up and down. It never made the schedule and was in discretion 2 out of 3 trips. The local XAA did nothing. It was our life blood contract for the winter. Eventually we lost the deal to a competitor unionised airline. After 1 month of total discretion trips the union said 'no more" and we won the contract back. This time the local XAA said we had to night stop for a few days until the next rotation. The original schedule had been driven by greed of the airline and allowed by the local XAA. If no stop is put to this it will just get worse and worse. The difference between the working life-style in union and non-union airlines is massive. The Tollpuddle martyrs were centuries ago, but they are needed once again. The vocational occupation we are involved in is being destroyed and our resistance is so low because it is vocational. We are our own worse enemies. When will the truth dawn upon the doubters? it did me and I'm out.