You would think that spotting a pilot taking a well-deserved snooze during a flight would be reassuring.

Because, you know, the fact that they're in control of the lives of hundreds — including your own — while you speed through the skies makes it pretty crucial that they're not fatigued, right?

Or perhaps it would it be better if they nodded off out of sight of the passengers, behind the controls?

Yeah, we thought not. But apparently a well-rested crew isn't a top priority for some passengers who have hit out at a photo showing a pilot sleeping in first class.

The photo was taken on a United Airlines flight. Photo / 123RF
The photo was taken on a United Airlines flight. Photo / 123RF

The photograph was taken on a recent United Airlines flight between Newark, New Jersey to Glasgow, Scotland by a man described as "a retired police inspector who now works as a security adviser".

The unnamed passenger told the Daily Record of their shock at watching the pilot disappear into the lavatory before removing his uniform, laying it on the seat next to him and dozing off.

But it stinks suspiciously like flight crew shaming, and more than a dash of jealousy from economy passengers.

"The captain went to the loo and changed into a T-shirt before going for a sleep in first class," the man said.

"When he woke up, he changed back into his uniform and radioed for access back to the cockpit. Police officers get a hard time when they are photographed sleeping in a patrol car.

"I don't think the captain of a flight packed with hundreds of people should be in such a vulnerable position. He slept for an hour-and-a-half, then the first officer went for a sleep. The flight was about seven hours.

"Surely if pilots are in need of a rest mid-flight, they should do it away from the passengers. I've travelled to the US many times and have never witnessed this."

Aviation expert David Learmount agreed that it was "most unusual".

"It appears as if the crew member is having an organised rest," Mr Learmount said. "Sometimes airlines operate with an augmented crew — that's three pilots when two are needed. But they don't usually do that on a flight from the US east coast to the UK."

The Daily Record also quoted an anonymous cabin crew member who works for a "major airline" as saying: "This is not a procedure I recognise. It seems highly unusual for a captain to remove his uniform during a flight.

Inside the pilot rest area in a Dreamliner. Photo / Flickr
Inside the pilot rest area in a Dreamliner. Photo / Flickr

"It also seems strange that a pilot should have what's known as a flat rest on a flight that is under 11 hours … It's understandable that some passengers would be concerned."

Meanwhile, popular airline group A Fly Guy's Cabin Crew Lounge shared the story on Facebook and sassily captioned it: "Passenger takes to social media to complain that his pilot was having a rest on his overnight flight across the Atlantic. I mean who wants a well-rested captain in control of their life anyway!

" … I know we crew appear to be super human with all our abilities, especially the one to deal with idiots like yourself, but we too need to sleep and use the toilet like other mortals!"

One commenter was outraged by the snap: "He wanted to sleep in F/C instead … and for free, as usual".

But most came out in support of the pilot. One cabin crew member retorted: "On a long night flight, it's law, there are three pilots, when we take off one goes straight to a bunk, then they rotate.

"I'm a flight attendant, the sleep depravity and fatigue you suffer in this job is horrendous, you only need two of them flying the plane, so we have three so that one can always rest.

The suite is pretty sweet. Photo / Flickr
The suite is pretty sweet. Photo / Flickr

"I wouldn't want to be on a flight where any of the flight crew are fatigued, would you?"

Another wrote: "Dear maker of this photo, there is a legal requirement for crew to rest! So mind your own business, sit back, relax and enjoy your flight."

And a third said: "Some planes don't have a crew rest area and pilot are entitled to a first class seat (when they are three flight crew) the relief pilot takes over but usually they are able to hide that seat with curtains for privacy."

So if you see a pilot snoozing in the cabin, just remember, not all planes have those fancy designated crew rest areas that you see on planes such as the Dreamliners.

United Airlines also defended the pilot, telling he was on a mandated rest break.

"The safety of our customers and employees is of prime importance at United Airlines," the spokesperson said.

"On transatlantic flights, pilots are required to take a rest break. This aircraft is operated by a cockpit crew of three and this pilot was on his rest period."

Fatigue is a serious issue facing pilots. America's National Transportation Safety Board (NTSB) says it "has long been concerned about the effects of fatigue in the aviation industry".

"The first aviation safety recommendations, issued in 1972, involved human fatigue, and aviation safety investigations continue to identify serious concerns about the effects of fatigue, sleep, and circadian rhythm disruption," the board said.

"Currently, the NTSB's list of Most Wanted Transportation Safety Improvements includes safety recommendations regarding pilot fatigue."