In early 1945, the massive American base being constructed at North Field, Tinian, was selected to be the operational base for the 509th.
  Subsequently many of the group's pilots flew to Tinian on ATC planes to familiarize themselves with the routes to be flown by the units B-29s and C-54s.
 The short-legged C-47s would remain at Wendover.

All through April 1945, the group's Ground Echelon was processed for overseas deployment.
It got off to a smooth start on 26 April when a troop train departed with 40 enlisted men and 2 officers, arriving at the Seattle, Washington Port of Debarkation on the 28th.
The Ground Echelon gathered in Seattle and deployed on 6 May aboard the SS Cape Victory.
At Wendover, Major Sweeney was transferred to be the commander of the 393d Bombardment Squadron and he was replaced by Captain John J. Casey, Jr.
In May 1945 the squadron moved to North Field, Tinian, transporting men and materiel of the 509th group as the group moved to its operational base.
For the reason that freight took priority over passengers, the Rear Air Element of the 320th remained at Wendover, and flew the squadron's C-47s to ferry necessary equipment to the base, which would be transshipped to Tinian on the C-54s.
Meanwhile on Tinian, the flying crews of the 320th were making continual round-trip flights to and from the States, as well as flights to Okinawa and Iwo Jima, carrying civilian technicians and their equipment.
Five C-54s made the deployment to Tinian, and the planes were indispensable in the perpetration of the 509th for its combat missions.

After the 393d Bomb Squadron two Atomic Bomb combat missions to Hiroshima and Nagasaki Japan in early August, the 320th on Tinian was engaged in carrying military and civilian experts to Japan after its subsequent surrender.
In early 1945, the massive American base being constructed at North Field, Tinian, was selected to be the operational base for the 509th.   Subsequently many of the group's pilots flew to Tinian on ATC planes to familiarize themselves with the routes to be flown by the units B-29s and C-54s.  The short-legged C-47s would remain at Wendover.
All through April 1945, the group's Ground Echelon was processed for overseas deployment. It got off to a smooth start on 26 April when a troop train departed with 40 enlisted men and 2 officers, arriving at the Seattle, Washington Port of Debarkation on the 28th. The Ground Echelon gathered in Seattle and deployed on 6 May aboard the SS Cape Victory. At Wendover, Major Sweeney was transferred to be the commander of the 393d Bombardment Squadron and he was replaced by Captain John J. Casey, Jr.
In May 1945 the squadron moved to North Field, Tinian, transporting men and materiel of the 509th group as the group moved to its operational base. For the reason that freight took priority over passengers, the Rear Air Element of the 320th remained at Wendover, and flew the squadron's C-47s to ferry necessary equipment to the base, which would be transshipped to Tinian on the C-54s. Meanwhile on Tinian, the flying crews of the 320th were making continual round-trip flights to and from the States, as well as flights to Okinawa and Iwo Jima, carrying civilian technicians and their equipment. Five C-54s made the deployment to Tinian, and the planes were indispensable in the perpetration of the 509th for its combat missions.
After the 393d Bomb Squadron two Atomic Bomb combat missions to Hiroshima and Nagasaki Japan in early August, the 320th on Tinian was engaged in carrying military and civilian experts to Japan after its subsequent surrender.
320th Troop Carrier Squadron