Man allegedly tries to sneak e cigarette on plane, sets off smoke alarm in bathroom Fox News Do Vapes Set Off Smoke Alarms? American Airline flight attendants found a man vaping in the bathroom. He posted a video of what came next. Smoking or vaping is not allowed on any flight to or from the United States. You can carry an e cig in your hand luggage, but you cannot use it in the cabin. Do Vapes Set off Smoke Alarms? Will a Vape Set Off a Fire Alarm? What to Know