I just PM'd SASless with this:
I know Sikorsky provided pilots for PHI to get them started (I used to do this, too, I flew at KLM Noordzee for a few months in the 70's).
I would guess that these pilots would cross a picket line.
Honestly, I probably would, not because I didn't agree with the strikers, just because my job is what it is, and that is the deal I made with my company. Were I a union employee for a company, I would probably honor the picket line.
Tough times call for tough decisions.