Many years ago, I was flying RNO-DFW on an AA 727, and was seated near the front of the coach cabin. Shortly after take-off, I heard a "ding, ding, ding" coming from the cockpit. Having previously seen the movie "Fate is the Hunter," I suspected that I was hearing the fire-alarm signal. The plane cruised at a low altitude for a while, apparently dumping fuel; a flight attendant informed us that we were returning to RNO; and on landing, the emergency vehicles were out alongside the runway. Fortunately, as the pilot then informed us, there was no engine fire, just an apparently malfunctioning alarm system.