Originally Posted by FlyingKat

UAL didn't block anything. They could no longer provide assurances to Republic that the XRs would be replaced with 145s because UAL pilots were successful in keeping their scope so the whole deal fell apart in August. Mana Air is UAL's backup plan to get better control over the 145 flying. We'll see if TSA is part of their plans, but it is most likely the XRs are with or without TSAs cooperation.