Tread carefully as the info above is not all correct based on my own experiences. The part of the UK / NL treaty that affects employment income tax for pilots is dependent on the nationality of the airline for whom you work and where it is headquartered, the % of the time your work is in the UK and the % of time spent flying ‘international traffic’
Expect to pay the lion’s share of your income tax in NL if your main home is there.
You’ll also pay 100% National Insurance in the UK if your home base is in the UK and you cannot opt out / choose to pay it elsewhere.
Don’t take advice from pprune but from a qualified tax advisor in both countries. Believe me, I speak from experience.