John Wayne is at his worst here but it is not as obvious why he made this movie as you think. This film was the brain child of Howard Hughes. This film is cinema "Spruce Goose" & it is possible it didn't even fly that far.
A large part of the cast & crew of this film died from Cancer including Wayne. It was shot on the New Mexico desert near the a-bomb test areas which is speculated as the cause.
This is an RKO production 1 year before the studio was sold to Desi & Lucy. Maybe this is why the studio was sold. I mean, the once proud studio of King Kong putting out a movie that could be named Ding Dong?
Sadly, a talented cast goes down too. This film might be why Hughes was a recluse in his later years. The joke goes that this film set is where Howard Hughes hid his will. Maybe while someone was out in the desert looking for that document they found the first trace of the real genius who wanted this movie made - Irwin R Shyster?