I'm not sure how it goes down in the USA, but here in Canada, federal transport workers are de facto prohibited from striking or other job action. Every time they go on strike, the next day the government passes legislation declaring the strike illegal because they are essential workers and a disruption poses a threat to infrastructure of national interest, and a new binding labour contract is imposed on the workers. The only legal option is to quit. (But you can't even encourage your coworkers to quit, too. That amounts to illegal labour agitation.) Air traffic control, port workers, railway workers, etc. get this treatment. They have no right to strike, in practice.
Edit: a quick Google search suggests it's same situation in the USA:
> The House has passed a resolution 290-137 that would force unions to accept a tentative agreement reached earlier this year between railroad managers and their workers and make an imminent strike illegal.
https://www.npr.org/2022/11/30/1139876084/congress-house-rai...