Long-haul journeys can be exhausting for hardworking flight attendants as well as passengers, but where do crew go to unwind and escape demanding flyers?
Many Boeing 777 and 787 planes feature a secret staircase that leads to a tiny set of windowless bedrooms known as Crew Rest Departments (CRCs).
Fascinating images provide a rare glimpse inside these confined areas, which few people have a chance to witness for themselves.
Most flyers are unlikely to have spotted the area before, as its narrow stairs are concealed behind a door, which usually requires a code or key to access it, and sleeping areas for crew are discreetly hidden above their heads.
The size and position of these spaces varies depending on each aircraft model, but they are typically nestled away behind the cockpit area, located above first class.
One image of an American Airline's Boeing 777 300 even shows staff members entering the relaxation areas through a hatch disguised as an overhead bin.
The accommodation is cramped and features an average of eight beds, depending on the airline.
On Boeing 777s, there are between six to ten beds, each containing storage space for flight attendants' belongings during the journey.
This model of plane also includes a separate area for pilots, with two beds, two business-class seats and, in some airlines, a bathroom area with a sink or lavatory.
Some bays come with entertainment systems, a blanket, pillows and on occasion, pajamas, with each bed separated by draped heavy curtains which muffle out the sounds of other crew.
Different airlines have opted for varying bed layouts, ranging from Malaysian Air A380s, which has beds stacked on top of each other, to American Airlines Boeing 773s, which has beds sectioned-off from a central aisle.
A British Airways flight attendant revealed to MailOnline Travel: "On the Boeing 747s it is all bunk beds and on the 777 it feels like you are in a coffin.
"They are cramped but you can make it comfortable as you get a blanket and a pillow.
"I always take my own pajamas and I make a little bed up. I sometimes try to take pillows and blankets from business class if they aren't in use.
"It's very basic, some have TVs but they are tiny, smaller than iPad minis."
There is a strict policy of one staff member to each bunk, which usually stretches 6ft long by 2.5ft wide.
Dan Air, the flight attendant behind Confessions of a Trolley Dolley, which has thousands of fans on Facebook and Twitter, told MailOnline Travel: "Crew rest areas on certain aircraft are a lot better than they used to be.
"They are very small and very cramped and yes can be very claustrophobic. It's not nice being in the tiny, confined space during severe turbulence, it can get very unnerving.
"In terms of what staff do there, well that would be telling, but I'm sure you can imagine that a lot more than sleeping often goes on here.
"We try to make them as comfortable as possible for us, bringing our own pajamas, blankets and teddies to try and help us get some sleep, but to be honest it's often very difficult to sleep."