Airbus has called on the aviation industry to set a minimum 18-inch seat width.
The manufacturer today revealed research into the impact that seat width makes on passenger comfort during long-haul economy flights.
And it has now called on airlines to enforce a minimum width of 18 inches (45.72 cms).
The study, by The London Sleep Centre, used polysomnography to record every standard physiological sleep measurement – including monitoring brainwaves, eye, abdominal, chest and hip leg movement – on a selection of passengers.
Researchers found that a minimum seat width of 18 inches improved passenger sleep quality by 53 per cent when compared to the 17-inch standard, which was first introduced in the 1950s.
Dr Irshaad Ebrahim, of The London Sleep Centre, said: "The difference was significant. All passengers experienced a deeper, less disturbed and longer night's sleep in the 18-inch seat.
"They went from one sleep stage to the next as you would expect them to do under normal circumstances.
"While in the narrower 17-inch seat the passengers were affected by numerous disturbances during sleep - which meant they rarely experienced deep restorative sleep.
"When it comes to flying long haul in economy, an inch makes a huge difference on passenger comfort."
Airbus has long provided a standard 18-inch minimum seat width in its long-haul economy cabins. However, not all manufacturers have done so.
Kevin Keniston, Airbus' head of passenger comfort, said: "If the aviation industry doesn't take a stand right now then we risk jeopardising passenger comfort into 2045 and beyond – especially if you take into account aircraft delivery timetables combined with expected years in service.
"Which means another generation of passengers will be consigned to seats which are based on outdated standards."
Air transport has changed significantly over the last 50 years. In the last five years alone, the number of flights over 13 hours has increased by 70 per cent from 24 to 41 daily. And in the next 15 years passenger traffic will double.
Not to mention man as a species is getting bigger so therefore needs larger seats.