The rudder has jammed on Joe's submersible plane and now it's heading right at the torpedo-spewing mechanical monstrosity guarding the underwater cave which is Joe's destination. The robot fires a barrage of torpedoes, Joe seems done for...then Frankie passes her own plane in front of him, drawing the torpedoes off. Then she turns and bears down suicidally on the robot herself — but just before she and the torpedoes hit, she ejects, her ejector seat propelling her up through the water, then after she bursts out of the surface turning into a jetpack and flying her safely to the flying base. Happens in such quick succession it's kind of dizzying.
Even Polly (a rival against Frankie for Joe's affections) is impressed.
Dr. Totenkopf is portrayed in hologram only, as a literal talking head. The man playing him had died fifteen years before the movie was made, at the age of 82. What they did was use very early test footage of the actor. The man's name? Sir Laurence Olivier.