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.