For some people, boarding a plane is nerve-wracking. We're thinking of all the things that can go wrong on our flight. For others, flying is annoying and a hassle, especially when flights are delayed or canceled due to the bad weather. When that happens during Thanksgiving or Christmas, for example, the whole terminal is full and everyone is in a bad mood. It's not the way we want to spend our holidays! Then there's more bad news, like being involuntarily bumped from our flight, having our flight being overbooked and finding affordable seats before we hit the sky, for example. We haven't yet heard from someone who loves flying, but that's not to say these people don't exist.

Did you know that a flight attendant will cut you off while you're over the Bermuda Triangle?  Did you know that if your flight is overbooked, you can get a cash reimbursement? What about when you are involuntarily bumped from your flight? It's a requirement by DOT to compensate you up to 400% of your ticket value if your involuntarily delay goes over two hours.

The truth is, there's a lot we don't know about flying. That's because there are many things that airlines keep to themselves and do not want us to know. But we have to know these things; otherwise, we will miss out on all the perks and the upgrades that airlines offer, for example. And then there are things we didn't know about, but we could easily ask any airline employee, such as your gate attendee or your flight attendant.

With all that in mind, here are 13 things airlines don't want us to know--and 12 things that we can just ask.

25 Hidden: What We Can Get If Our Flight Is Overbooked

If your flight is overbooked, and you're not in a hurry to get to your destination, take advantage and know beforehand what you can do. An airline employee will announce if there are any volunteers to give up their seat. Then the airline will offer you a voucher, which is worth $200.

But know going in what the airline won't tell you, that you can ask for cash, and maybe a little more than $200.

The airline, in fact, will write you a check right then and there, at your terminal. Now you've just got some more money in your wallet!

24 Ask: Why The Airplane Door Hasn't Yet Been Closed

The next time you fly, don't spend a lot of time trying to fit your bag in the overhead bunker or trying to fit your laptop and carry-on bag under your seat. You are going to delay a flight, which is why a flight attendant will come to your assistance.

They won't be offended if you ask why the door isn't being closed; it turns out that flight attendants and on-ground assistants aren't being paid during holdups, which means they are only paid when the aircraft pushes away from the gate.

23 Hidden:  What We Can Get If We're Involuntarily Bumped

When an airline doesn't have enough volunteers willing to give up their seats, they start bumping travelers involuntarily. This may sound pretty bad if it's Thanksgiving and you need to go home.

If you are chosen to vacate your seat, know that it's illegal if you object or, worse, put up a fight.

But the good thing is that the Department of Transportation will compensate you dearly. It's a requirement by DOT to compensate up to 400% of your ticket value if your involuntarily delay goes over two hours.  Also, compensation is capped at $1,300.

22 Ask: A More Comfortable Seat

We've all been through it while flying. Your seat isn't next to your companion or your seat has little leg room. Or your seat is stuck in the middle and it just so happens you're surrounded by annoying kids or someone whose physical frame forces him or her to occupy two seats.

But if your flight hasn't been sold out, or there are a lot of empty seats, you can ask your flight attendant for better ones.

They will personally take care of you and find more comfortable digs to make you happy.

21 Hidden: ABOUT Their Water Supply

The United States Environmental Protection Agency (EPA) created the Aircraft Drinking Rule Act in 2009 after their study found that most airplanes' supply of water was not clean at all and that their tanks were old and contain bacteria. At least now there are standards. And we now know why flight attendants only serve us bottled water.

Never order a drink with ice cubes, whether that's scotch on the rocks or Coke with ice.

The airplane's ice is derived from their water supply, and so the ice may get you sick.

20 Hidden: The Best Days To Fly And The Best Days To Book

Even airlines don't want you to know about airfares, specifically, when it's best to fly to get the best deal. One is dictated by business men or women.

They don't usually fly on Tuesdays and Saturdays, so those are the cheapest days to fly.

As for the best days to actually book a ticket, the most economical time to buy often fall between Tuesday through Thursday afternoon, according to HowStuffWorks. Never try booking a flight on a weekend, as that day everyone is off from work and they have the time to do some price comparison before booking a ticket.

19 Ask: An iPad For In-Flight Movies

On long flights, you'll get a free pair of headphones to watch 1 or 2 movies. But did you know that you can also ask a flight attendant if you can borrow an ipad to watch the same movies? You usually ask when your monitor isn't working for some reason.

But even if your entertainment system is working, you can get away asking for an ipad if you are flying with your kids.

That way, your children will be distracted and entertained for most of the flight; if they are acting up, this is a lifesaver.

18 Hidden: We Can Bring Food On The Plane

What's the thing we fear the most on an airplane beside turbulence and bumps in the air? The food! It's a universal joke that the food served on airlines is pitiful. They are often prepared five days in advance and then frozen. They are not fresh at all.

But did you know you can bring your own food on your plane? No one will tell you that.

But according to USA Today, there are no formal limits on how much you can bring. Just remember one thing: be considerate of others on your flight. Don't bring fish or smelly things like a dish spiked with a lot of garlic. You'll smell up the plane and you will become very unpopular, very quickly.

17 Ask: WHERE THEIR WATER CAME FROM

As we've mentioned, never ask for ice in your drink because the airline's source of water is not exactly the cleanest. But you can ask a flight attendant to verify this.

You can ask why he or she is only passing out bottled water, or if you see that no one on board is drinking tea or coffee.

These travelers know the deal, and now you do too. Just be polite when you ask and your takeaway will be not getting sick from water that's not bottled or used to make coffee or tea.

16 Hidden: We Can Negotiate When We're Involuntarily Bumped

Only about 10% of people get bumped against their will. If that happens, the airline, as we've said, is forced to compensate you for a mutually acceptable price.

The airline doesn't want you to know that, and they also don't want you to know that you don't ever have to take the airline's first offer.

So you can negotiate. But remember to ask about restrictions if the airline offers you a transportation voucher in a certain dollar amount. You need to know how long that voucher will last, if you can use it during peak times like holidays, and whether or not you can use the voucher for international flights.

15 Ask: Why We Can't Have Diet Coke On A Flight

According to Hello Giggles, if you choose to ask for a Diet Coke from the drinks trolly during your flight, your flight attendant will not deny you the soda. But there are times when an attendant will offer you an alternative--like ginger ale or regular Coke--and if you ask him or her why you can't get the Diet Coke, they won't lie and say that it's out of stock.

Instead, they will tell you the truth, that Diet Coke takes the most time to pour because the fizz takes a lot of time to settle up in the air.

In that time, an attendant could've been serving three other passengers.

14 Hidden: Our Rights If We Are Bumped

Now that you know you can negotiate if you are bumped, make sure you know your rights, as airlines won't tell you them. According to DOT, you cannot receive any money if you reach your destination within one hour of your previous arrival time when you're put on another flight.

As we've pointed out, if you are delayed for more than two hours, you're owed 400% of your one-way ticket. If it's less than two hours but more than one, the airline is forced to pay you 200% of your one-way-ticket.

13 Ask: If We Can Have More Food

Chances are you won't even finish your in-flight cuisine because it's not very good. Who in their right mind would ask for seconds? And can you even ask for seconds? This is another thing you can ask.

If you're still hungry after your first meal, many don't know that you can get a second one at no cost if you ask politely.

You will not be laughed at or frowned upon and you will get what you asked. That's mostly due to the fact that those food containers have a short shelf life and that they all go to waste because unused ones are immediately discarded at the end of a flight. The only time you'll be denied is if there are no leftovers.

12 Hidden: The Free Upgrade

Upgrades were more frequent in the past, and nowadays airlines expect travelers to pay for them. According to Boarding Area, a free upgrade these days happens only for operational reasons. For example, like if all seats are oversold and the airline is forced to upgrade people. But you still can try to get a free upgrade.

Just think of asking for it as if you are at  a job interview and you may just get what you want--a fact an airline would never tell you.

According to Skyscanner, looking nice and being extremely polite to gate agents and flight attendants goes a long way when asking.

11 Ask: Fresh Blankets and Eye Masks

Every airline passes out lightweight blankets and masks. But it's kind of a secret that those comfort items aren't washed or changed after every flight. Instead, crews just fluff and nicely fold the blankets so they look new.

When flight attendants pass out headphones, you know their soft ear casings are clean because they are given to you wrapped in plastic. So if you don't like germs, it's not impolite to ask a flight attendant if you can get a blanket and a mask that has been wrapped to ensure no one has already used them.

10 Hidden: When A Non-Refundable Ticket Is Refundable

It happens to all of us. We want to book a ticket for our trip, but we're not certain about the day, and the more you wait, the more the airline ticket will be priced higher. If you book and you're uncertain, it looks like airlines won't refund you if you change your mind.

But according to the U.S. Department of Transportation, there'a rule that requires carriers to hold a reservation at the price you were quoted for 24 hours without payment or allow a reservation to be canceled within 24 hours without penalty. We would've never known that!

9 Ask: Extra Snacks And A Whole Can of Soda

So now we know that we can ask for another meal if there are extras. But did you know you can also ask for more free snacks and a soda? On most flights, you'll get a complimentary beverage and a small snack like a bag of pretzels, peanuts or a cookie.

If your flight is short and you're still hungry, don't feel weird asking the flight attendant for a whole can of soda (rather than a small drop in a plastic cup) and more peanuts. Most flights carry extra food, so ask away.

8 Hidden: 'The Involuntary Refund'

So now that you know you can get a refundable ticket, you have a day to think about taking it. Just know what airlines don't want you to know.

According to Airfare Watchdog, there's something called "involuntary refunds," which means that if the airline refuses to fly you for any reason, or if your flight is delayed significantly, (each airline time is different) or if your flight is just canceled,  you don’t have to pay the change or cancel fee after the 24-hour airline hold ticket. In fact, you can apply for a full refund, even on a non-refundable ticket.

7 Ask: If A Flight Crew Can Decipher Our Boarding Pass For Us

You probably don't look at your boarding pass unless you're looking for your gate. Everyone else--TSA, flight attendants--look at it. But while your boarding pass is made up of numbers that are undecipherable to us, we can ask flight employees what they mean, especially since the ticket has some sensitive material on it. The first two letters before the flight number refer to the airline.

The numbers indicate in which direction you'll be flying in--odd-numbered flights, for example, means you're flying south. The six-character text is your booking reference and the code can be used online to look up everything that's personal to you, like your age and credit card info. It's your info, so it's in your interest to ask.

6 Ask: Why We've Been Cut Off

Doesn't it feel better drinking on the plane? It calms your nerves if you dislike flying or puts you to sleep to make the flight seem shorter. But if you are under the influence and get tipsy, a flight attendant will cut you off. You can ask them why.

It's that it's actually illegal to be tanked on a plane and, not only that, it's illegal for flight crews to get you inebriated. Those little bottles pack a big punch up in the air; one hooch in the air can feel the equivalent to two on the ground. So don't mess with the flight attendant.