There are no "expat" pilots left in the SIA group, they were done away with a number of years ago. There are basically three types of employee:
1. Locals, or Singapore citizens.
2. Permanent residents or non citizens who can live in Singapore with out a time limit and work for anyone they like.
3. Foreigners employed in a specific position with a permit for a set duration and a single employer.
#3 is usually the one that gets let go first.