Factual error: In the opening scene, the Clampetts are driving home from Malibu. From Malibu to Beverly Hills is east. But as they head home, the ocean is on their left, which means they are driving west.
Continuity mistake: We see that the XL18 pilot is sitting in the right seat of the cockpit. In the next shot he has changed to the left seat.
Audio problem: When Judy asks "But Grandpa, why didn't you tell us what was going on?" towards the end of the episode, she is speaking with Jane's voice.