Facts about flying: No. 1, bathrooms don’t lock

We may never know what happened to that Malaysia Airlines 777, but there’s plenty more we should know about flying, even domestically. Here are some little-known truths of aviation as shared by pilots and flight attendants:

Lavatory doors don’t really lock: They can be opened from the outside by just sliding the “occupied” sign to one side. This isn’t so attendants can catch “mile high club” wannabies, but so they can be sure the lavs are empty on take-off and landing. And those ashtrays in the lavs? Even though smoking has been banned for decades, the FAA still requires them.

Oxygen masks can save your life: But only if you get them on fast! In a rapid decompression at 35,000 feet, the oxygen is sucked from your lungs and you have 15-30 seconds to get that mask on or die. And the on-board oxygen is only good for 15 minutes, so expect an express ride down to safer altitudes.

Airlines are suffering from a pilot shortage: New regulations for increased rest time and more experience aviators are making it tough for airlines to keep their cockpits filled. Boeing alone estimates that aviation growth worldwide will create demand for a half-million new pilots. And just like Metro-North, airlines are now losing their most experienced crews to retirement.

Your pilot may be asleep: Actually, that’s a good thing during most of the flight, which can be pretty boring as the auto-pilot runs the plane. And a good nap should make your pilot refreshed for landing. But the FAA is also proposing to test “heavy” pilots for potential sleep disorders so they don’t nod off at a crucial moment.

Keep your seatbelt on: Otherwise, unexpected turbulence will see you bounce off the luggage racks like a Ping-Pong ball. In an incident like that the hysterical screaming is bad enough, so stay belted.

Flight attendants aren’t in it for the glamour: They don’t get paid when they arrive at the airport or when they greet you boarding the plane. For most, their pay starts ticking only at take-off. They travel for a living and have to endure endless abuse for things that are not their fault. For all that, median salary for flight attendants is about $37,000.

Planes are germ factories: Most older jets recycle cabin air to conserve fuel, so if one passenger sneezes, everyone’s susceptible to a cold. The air is also dry and the blankets and pillows (if you get them) haven’t been cleaned since the previous use. The same is true of the headphones they pass out. And your seatback tray table? Just imagine whose baby diaper was seated there where you lay out your in-flight snack. Moral to the story: BYO sanitizer!

Don’t drink the water: Unless it comes from a bottle, water on planes comes from onboard tanks that are rarely cleaned. At least when they use it to make coffee it’s heated. Again, BYO.

Overall, based on passenger miles, flying is the safest form of transportation in the world. But it’s not without its risks, some of which you can help minimize using common sense.

Jim Cameron is the founder of the Commuter Action Group and also serves on the Darien RTM. The opinions expressed in this column are only his own. Email CommuterActionGroup@gmail.com for comments.