I was a Ryanair pilot
I joined Ryanair just because I fancied a break from UK weather. However, it turned out to be a very bad move for me. During earliy shifts I was waking up at 4.30am and not getting home until around 5pm (for 5 days in a row) - I didn't even feel safe to drive home and I'd just landed a jet with 195 people on board (myself included!)
Typical morning rosters from our base were CIA-STN-CIA-BVA-CIA and CIA-BGY-CIA-DUB-CIA - very long days indeed. You frequently got back on the 4th sector to find yourself facing very large thunderstorms or a VOR to circle visually onto the opposite runway - some 10 hours or more after you woke up at 4.30am. I couldn't believe it was legal to fly when I felt like I did. In fact, it's not legal in the UK.
The max duty time under UK rules if you report before 6am local for a 4 sector day is 9:15min. Under Irish rules you can still do a 12 hour flight duty with 2 hours of additional time for discression. For me, this was the most unsafe aspect of the whole operation and it turned me into a walking zombie every 2nd week of my life.
So, I wrote the following letter
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To: Base Captain (CIA)
From: XXXX - F/O (XXX)
Dear Xxxxxx,
Please accept this letter as my formal resignation from Ryanair. I have come to feel that, for me personally, the early shifts we are being asked to fly are excessively long and I often feel unsafe (particularly by the 4th sector) due to tiredness / fatigue. I can't continue to fly when I feel unfit for any reason, as is clearly stated in the Ryanair Operations Manual and is required by law.
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My resignation was accepted graciously by letter from Gen Mgr of Flight Ops and I was thanked for my support of the company. I left the company 1 month later with no further communications.