Re: Repeating:
Mentioning Flash Gordon made me think of Buck Roger's rocket (in those old 1930's era movie serials [as well as a possible full length feature film] with Buster Crabbe) that sounded a lot like the low droning sound of a pulse jet (not to be confused with the sound of a V1 during the WW2 blitz on London, which only posed a danger when the noise STOPPED)
(either that or it was the sound of a multi-engine airship of the same time period)
Biting the hand that feeds IT
