They are the myths and mysteries every passenger wants answers to.

From the safest seat on a plane to why some airlines don't include row 13 and what really happens to your waste, we reveal the truth about air travel, with some help from flight deal website Skyscanner.com.

Is It Safe to Drink the Water on Planes?

Some planes have unwanted stowaways in their water supply, including bacteria that could make you sick, according to tests by the U.S. Environmental Protection Agency in 2009. The water didn't meet safety standards in one out of every seven planes tested, with bacteria associated with human faeces like coliform and E. coli found. Bacteria can grow in the plane's water tanks and hoses, as the water is pumped on board through hoses that are difficult to clean. Best to be cautious on this!

Do You Really Get Drunk Quicker While in the Skies?

Not true, according to studies. Dr. Bhushan Kapur from the University of Toronto, Faculty of Medicine said passengers' blood alcohol level doesn't increase in the air. However, people do tend to drink more in a shorter time frame in the skies, which can leave them more impaired. So where does the misconception come from? The onboard effects of hypoxia -- less oxygenated conditions due to the low-pressure environment and high altitude -- can cause passengers to experience symptoms similar to intoxication.

What Happens to Your Waste?

Airlines are not allowed to dump their waste tanks in mid-flight, however leaks can occur. Numerous "blue ice" (frozen sewage material treated by a liquid disinfectant that freezes at high altitude) impacts have been recorded, including some where it has fallen through the roofs of people's homes.

For example, one UK couple were reportedly sitting in their garden when blue ice hit the roof of their house before landing on their heads. It gave off a "particularly pungent whiff of urine" as if thawed.

Do Flight Attendants Have to Be a Certain Weight?

There are no strict rules according to waistlines, but cabin crew must have "weight in proportion to height". They must be able to sit in the jump seat without an extended seat belt and fit through the emergency exit window. The acceptable height is approximately 160-185 centimetres.

What Happens When the Pilot Goes to the Toilet?

Ever wondered why the seatbelt sign randomly lights up during a flight? Well forget turbulence, it may be that the pilot has made a sneaky trip to the toilet. A cabin crew member will guard the flight deck door while the pilot makes the trip to the lavatory.

Can Lightning Cause a Plane Crash?

Passenger planes are inevitable targets for lightning, which strikes a commercial plane on average once a year. However, lightning hasn't downed a passenger plane since 1967. Planes have to pass numerous lightning certification tests. The outer skin of most planes is mainly aluminium - a good conductor of electricity. The current flows through the skin from the point of impact to another extremity point, commonly the tail.

Why Do Airlines Leave Out Row 13?

Some airlines remove row 13 from their planes so not to spook superstitious flyers, including Air France, Emirates, Continental Airlines, Lufthansa and Ryanair. Lufthansa also flies minus a 17th row as it's regarded as unlucky in Italy and Brazil.

Do Lavatories Have to Be Fitted with an Ashtray, Despite Ban on Smoking?

Smoking on planes has been banned for nearly 15 years, but all planes worldwide must have ashtrays to ensure flight safety. Why? A discarded cigarette sparked a plane crash in 1973, so the rule was adopted in case a passenger gave in to their cravings on a flight.

Can You Get High from the Emergency Masks?

Contrary to what Brad Pitt's character in Fight Club may think, the oxygen from the emergency masks won't get you high. It's actually a loss of oxygen that makes you feel this way, so that's why airlines provide the masks in case the cabin pressure suddenly drops.

Can Your Mobile Phone Cause a Plane Crash?

The jury's still out on this issue, but airlines are erring on the side of caution. Current regulations give crew the power to ban the use of any device that could threaten the safety of an aircraft. Experts say that electromagnetic waves emitted by mobiles can interfere with a plane's electronics and cause a crash, concerns that were outlined in an investigation by the New York Times last year.

Which Seats Are the Safest?

It's true - the safest seat should you be involved in a mid-air disaster is the emergency exit, according to researchers from the University of Greenwich commissioned by the US Civil Aviation Authority, who looked at the accounts of 2,000 survivors in 105 air accidents around the world. A seat up to five rows from an exit offers a greater chance of escaping if there's a fire. There's only a "marginal" difference as to whether the seat is on the aisle or not. It also found passengers at the front of the plane had a 65 percent chance of escape, while those at the rear had only a 53 percent chance.

Why Does Food Taste Different on a Plane?

It's not just your imagination - food really does taste different in the skies. Firstly, the atmosphere inside the cabin dries out the nose and then the change in air pressure numbs approximately a third of the taste buds. This explains why airlines tend to add a lot of salt and spice to food.