The noose was tightening around the Wehrmacht's neck.
You can read about this, and Spitfires and Hurricanes and the men who flew and maintained them, in Group Captain Johnnie Johnson's Wing Leader, a great read! The historical insight gained is worth its weight in gold, at today's prices!
For the record I must issue a correction to the marketing of this book: Johnnie Johnson, with 38 accredited enemy single-seat, single-engine fighter planes downed, is NOT the leading allied ace. He was the leading SURVIVING ace after the war.
The true, official leader was Richard Bong, U.S.A.A.F., who flew a P-38 over the Pacific and wreaked Japanese havoc: 40 Imperialist planes were downed by Major Bong before he was sent back home, where he was killed in an F-80 jet plane crash. Godspeed, Major Dick Bong!!!! And thank you and your brethren for our Liberty!!!!
Here's more on Major Bong: