Another award to ground personnel of all world’s air forces. Mechanics checking the propeller of an of four engines of a B-17G of 99th Bomb Group, 5th Bomb Wing, USAAF. Note the twin gun barrels nose turret traversed to right. Tortorella Airfield, Southern Italy, 1944. 

Turning props

Tortorella Airfield, Foggia Airfield Complex, Southern Italy, 1944: mechanics overhauling a B-17G of 99th Bombardment Group, 5th Bombardment Wing, US Army Air Force. Victor Sierra

Overhaul

From "Thunder From the South-The 99th Bomb Group in World War 2" in website of USAAF’s 99th Bomb Group Association: “In eighteen months of operation, the 15th Air Force destroyed half of all petroleum production in Europe, a good part of German fighter production, and had crippled the enemy's transportation system. The 15th dropped a total of 303,842 tons of bombs on enemy targets in twelve countries. In all, 148,955 heavy bomber sorties were flown. The 15th, an outfit that the 8th Air Force referred to as "minor leaguers," had done a major league job. This in spite of the fact that the 15th had many fewer groups than the 8th. It is unfortunate that the 15th Air Force has received virtually no historical recognition. Almost all books, movies, etc., have focused on the 8th Air Force. Many people who study B-17s are surprised to learn that there even was a 15th Air Force operating from Italy as the 8th operated from England. The Axis countries had no doubts about the existence of the “"Thunder From the South"”  The Fifteenth Air Force was established on 1 November 1943 as part of the United States Army Air Forces in the World War II Mediterranean Theater of Operations as a strategic air force and commenced combat operations the day after it was formed. The first commander was General Jimmy Doolittle. The Fifteenth was de-activated in Italy 15 September 1945. In the photo two B-17s of an unit of 15th AF, 483th Bomb Group, in flight over Alps. Victor Sierra