While on a tour of the United States, Caldwell visited Curtiss-Wright in Buffalo, New York. On 6 August 1942, he was invited to come on an acceptance re-flight of a Curtiss C-46 Commando, the latest transport aircraft destined for overseas use. The aircraft was also loaded with Curtiss executives, and flown by Chief Production Test Pilot Herbert O. Fisher. The landing gear became stuck in a three-quarters down position, and after an extended eight-hour attempt to release the gear, Fisher calmly belly-landed the C-46. With the weight of the aircraft gently pushing the gear back into the wheel wells, a minimum of damage resulted. Caldwell had taken over as the co-pilot on the eight hours of circling over Buffalo, receiving certification that he was checked out on the C-46, under the tutelage of Fisher. Finishing his tour at Curtiss-Wright, Caldwell went on to visit the North American Aviation factory and was able to personally evaluate their new P-51 fighter, then in development.