S1·E29 Unidentified Flying Uncle Martin

Martin needs to fly his space ship, which is deteriorating due to inertia. Tim's fear is realized: Martin's flight is spotted as a UFO. Martin needs to take another flight, but Mrs. Brown calls in the authorities - Jack and Jim being their representatives - who use Tim and Martin's apartment as a sighting station. Martin uses the opportunity to take his second flight since Jack and Jim have equipment - a plutron counter - that would be able to locate the space ship parked in the garage. The plutron counter does go off, but Martin slips some plutron into Mrs. Brown's apron pocket, making the plutron counter point in Mrs. Brown's direction. Jack and Jim think the machine has gone haywire. During Jim and Jack's kafuffle with Mrs. Brown, Martin slips away. While in flight, Tim further distracts Jack and Jim with a spoon dangling outside on their tree, which through Jack and Jim's telescope will look like a flying saucer. Martin takes his flight undetected and gets back to the apartment safe and sound. To further protect himself, Martin exposes Tim as the perpetrator of the flying saucer hoax - all in the name of getting a news story - with the spoon on the string as his proof of his claim.