Well depending on how accurate his dimentions are and the data here is the radius.
Powered by a 2,500 HP R-3350-24W engine turning a 4-bladed 13.5 foot prop the AD-1 Skyraider was capable of carrying 4,000 pounds of bombs and/or wing loaded rockets.
Only thing that blows the therory is the cap, I havent seen a skyraider with a cap. May if you can remove it then compare it with the front of a skyraider picture. Cap could have been removed in later models.