Southwest Airlines is currently in the rolling_out phase with a high fleet coverage ratio of 86.2%, but as of now, no aircraft are equipped with Starlink and no confirmed observations exist on the STL->AUS route. The rollout is announced to begin in summer 2026, so current probability is anchored low due to zero equipped aircraft and zero observations. Given the high fleet coverage expected post-rollout, the probability is set slightly above zero (0.10) to reflect imminent deployment but no current evidence.