5 Surprising Secrets About Air Travel If you think you know it all when it comes to traveling on a plane, Business Insider has provided this list of air travel secrets that might just surprise you. 1 The lock mechanism is usually hidden beneath the "no smoking" sign in case of an emergency. 2 If they're on an hourly wage, their paid time starts when the plane door closes and ends when it opens. 3 The authority of the pilot in command extends to ordering a passenger restrained, writing fines, taking a will and refusing entry to a person who looks sick. 4 The chimes can inform the crew of anything from how many snacks are left to an emergency or change of route. 5 While this may sound shocking, a pilot can drop a plane to a safe altitude well before the oxygen runs out.