sentences:  Hall became the first Eagle Squadron pilot to become a Prisoner of War (POW) when he was shot down during an escort mission.The squadron's first confirmed victory came on 21 July 1941 during a bomber escort mission, when Pilot Officer William R. Dunn destroyed a Messerschmitt Bf 109F over Lille.In August, the Spitfire Mk II replaced 71 Squadron's Hurricanes, before the squadron quickly re-equipped with the latest Spitfire Mk VB.