My great uncle, Ed Gray, was a P-47 pilot of the 318th, and can verify all this. He is 96 and is quite healthy. Their take-off was delayed because they had to wait for the airfield to be captured on Saipan. Even then, it was only under partial control... so they landed on the held end of the field and did a controlled ground loop as soon as they could and high tail it back to the safe end. This was not just a ferry detail. They took off loaded and made an attack on the flight in. The navy pilots onboard coached them on how to launch with the catapult. Here is a link to some footage: http://www.criticalpast.com/video/65675047538_P-47-Thunderbolt-fighters_Major-John-Hussey_P-47-catapulted-from-carrier_Navy-personnel
He also flew the P-38 Lightning. We just visited the Lockheed Martin plant today to tour the F-35 Lightning II production line.