"Tarzan Triumphs" was Johnny Weissmuller's first RKO film, and his seventh as Tarzan. It was directed by William Thiele in 1943 and also starred Frances Gifford as Zandra; Johnny Sheffield as Boy; Stanley Ridges as Colonel Von Reichart; Sig Ruman as the Sergeant; and Phillip Van Zandt as Captain Herb Baush.
This clip was taken from a documentary called "Tarzan at the Movies" (1996) and the enjoyment of the trailer is marred by the narrator's commentary. I plan to replace this clip with an untainted copy of the trailer when I find it. If you can help me out with this please drop me a line.