1. You can be booted off a flight for your stench

Several airlines, including three of America’s biggest - United Airlines, American Airlines and Delta Air Lines - can remove any passengers with a “malodorous condition” or an “offensive odour” from the flight. Back in 2010, a male passenger on an Air Canada Jazz flight was asked to disembark the flight after fellow fliers reportedly complained of a “brutal” body odour.

'Offensive' body odour could lead to a marching order on a flight Credit: © Miriam Dorr / Alamy Stock Photo/Miriam Dorr / Alamy Stock Photo

2. ...or going barefoot

Tied to the bad body odour rule but also for safety reasons during emergency evacuations, passengers who aren’t wearing shoes can be refused boarding. Passengers can also be refused boarding if they are deemed to not be “properly clothed” or wearing clothes thought to be offensive to fellow passengers. Just last month, a group of women travelling to Magaluf on a hen do was removed from a Jet2 flight for reportedly wearing t-shirts that read “Bitches on tour”.

No shoes, no entry. Credit: AP

3. Mohawks are banned

Think passengers have it bad - spend a thought for the crew. Airlines generally require flight attendants to have a “groomed look that meets conventional standard”, as British Airways describes. Hawaiian Airlines believes “unacceptable hairstyles include, but are not limited to, extreme or unnatural colors (e.g., pink, purple), top-knots, dreadlocks, cornrows and Mohawks," while American Airlines believes "hairstyles may not be more than three inches in fullness and may not wave or curl outward to extreme volume".

You won't find a flight attendant with this hair-do Credit: AP

United also takes a strong stance on facial hair on male flight attendants, saying “ trendy facial hair styles are not permitted (e.g., small patch of hair growing below lower lip)" for men and "mustaches may not extend more than ¼ inch below the sides of the mouth", while Jet Airways is said to require “a clear complexion (scars, pimples and blemishes not acceptable)".

4. ...while men can’t wear makeup

"Male flight attendants may not wear make-up” on United Airlines flights, while "lipstick or gloss are required and should complement the facial features. Lip liner should be used in moderation" by Allegiant Air female flight attendants.

An air stewardess applying lipstick Credit: AP

“Makeup should be freshened as necessary, but never in view of the customer" American Airlines believes.

5 ...and jewellery is restricted

"Hoop earrings are permitted and may be no larger than 1½ inches in diameter and/or ½ inch wide on the surface" for Hawaiian Airlines cabin crew and United Airlines is reported to allow "a total of four rings” to be worn, with "no more than two on each hand” by each flight attendant.

6. Animals are allowed on board as “emotional support”

Most airlines allow passengers to travel with an animal on board used for emotional support or as a service animal. But the mammals that fall under this category can vary according to the airline. British Airways only allows assistance dogs while United bans pit bull dogs and “certain unusual animals/reptiles”, including snakes, ferrets, rodents and spiders, that “pose unavoidable safety and/or public health concerns” and cannot be carried as cabin baggage.

A post shared by Bobby Portugues (@captainpu55y) on Apr 27, 2017 at 7:11pm PDT

7. ...but monkeys need to be small

United also accepts certain breeds of monkeys on board, but they must be small enough to fit in the space under the seat in front of you “without invading another passenger’s seat area during the entire flight”. Many airlines also allow birds of prey in the cabin.

8. Antlers are also acceptable (as long as they’re clean)

Delta accepts antlers as checked baggage (subject to a fee), but they must be “as free of residue as possible” while the “skull must be wrapped and tips protected” and its “linear dimensions must not exceed 115 inches”. The antlers must also not weigh more than 70 lbs, while those weighing more than 100 lbs will not be accepted.

Antlers must not still be attached to the deer Credit: AP

Meanwhile in 2015, the airline banned the shipment of all lion, leopard, elephant, rhinoceros and buffalo trophies worldwide as freight, following the killing of Cecil the lion that year.

8. …as are human remains

Easyjet and Ryanair allow human remains to be carried on board in addition to your normal cabin baggage, so long as they’re cremated and “securely packaged in a suitable container with a screw top lid” to avoid any mid-flight spillages.

Human remains are allowed on board but must be in a sealed container Credit: AP

9. Some babies are banned

Airlines typically do not allow babies under the age of seven days to fly, but the limit is sometimes 14 days.

10. ...but dead passengers get upgrades

“In a nice, easy world – where someone dying on an aircraft isn’t – you put them back on seats. I know a crew member who had to sit next to someone who passed away for the rest of the flight,” a lead trainer at British Airways told Telegraph Travel.

Once seated, flight attendants should “tuck a blanket” right up to the corpse’s neck, she added. If there is space in first class, they will often be placed there, and nearby passengers informed.

British Airways used to prop up dead passengers and pretend they were dozing Credit: AP

The system wasn’t always thus. The trainer went on to explain that British Airways used to prop up dead passengers and pretend they were dozing.

11. Obese fliers can be kicked off a flight

United reserves the right to remove any fliers who are deemed to “significantly encroach upon the adjoining passenger’s seat” or “unable to sit in a single seat with the seat belt properly secured, and/or are unable to put the seat’s armrests down when seated and remain seated with the armrest down for the entirety of the flight”. In 2013 Samoa Air famously courted controversy by beginning to charge passengers according to their size.

Cabin crew can also face the same threat for their physical characteristics. Back in 2015, Air India warned 600 of its 3,500 crew to lose weight within six months or risk being taken off flights, while Air France announced back in 2010 that overweight passengers would be asked to pay for two seats or be refused boarding for “safety reasons”.

Some airlines have charged passengers by weight

12. Unruly passengers can be tasered

Last year, new guidelines from Korean Air Lines said the South Korean carrier will allow crew members to "readily use stun guns" to manage violent passengers, as well as ban any passengers with a history of unruly behaviour. In South Korea, the number of unlawful acts committed aboard airplanes has more than tripled over the past five years, according to government data.

14. Nut allergies can lose you your seat

Nuts on planes have been a touchy subject since the “nut rage” incident on a Korean Air flight back in 2014. But last year, one family was removed from a flight after it emerged that their two-year-old son had a peanut allergy. The family travelling on the Allegiant Air flight was asked by the pilot to get off of the plane for potential safety reasons, a decision which was reportedly made after the crew consulted with a medical profession.

15. Pilots are not allowed to speak until they pass 10,000 feet

The Sterile Cockpit Rule means that during take-off and landing - before the aircraft passes 10,000 feet on ascent and after it has passed 10,000 feet on the approach - pilots must focus entirely on “their essential operational activities” and “avoid non-essential conversations”.

“Sterile flight deck procedures are meant to increase the flight crew members’ attention to their essential operational activities when their focused alert is needed,” reads the code, which applies to all aviation authorities in the EU, including the British Civil Aviation Authority (CAA).

The regulation began life in the US in 1974 in response to the crash of Eastern Air Lines Flight 212, which fell just short of the runway at Charlotte Douglas International in heavy fog, with the loss of 72 lives.

Despite the poor visibility, investigators determined that the cause of the crash was in part due to “the flight crew’s lack of altitude awareness at critical points during the approach due to poor cockpit discipline”.