Just when you thought modern air travel couldn’t get any more cramped, think again.

New airline seating design concepts showcased at the annual Aircraft Interiors Expo in Hamburg, Germany last week showcased some high-flying ideas to maximize guest capacity, including seats that face each other, lightweight materials and even seats that flip up like stadium seating, according to USA Today.

One of the over 500 companies exhibiting their ideas was French company Expliseat that featured a model made of lightweight titanium and composite materials, weighing in at just under 9 pounds compared to the standard 24, according the LA Times. The company estimates that airlines can save up to $500,000 a year in fuel costs due to the lighter load.

Many companies focused on the efficiency of cabin seating. Zodiac Aerospace debuted a set of row seats in which one passenger faces backward, while two face forward. The seats flip up, similar to stadium-style seating, to allow passengers to get on and off the plane faster. Missing from this design are the traditional arm rests. 

British interior manufacture Thompson Aero Seating created a new idea called a “cozy suite.” These angled economy seats sit on a slight diagonal to maximize space usage.

“There is no question that densification — adding more seats to each aircraft — is an ongoing trend and there is no sign of it letting up anytime soon,” said Seth Kaplan, managing partner at the trade publication Airline Weekly, told the LA Times.

Many of the ideas presented in Hamburg will likely never see the inside of a real plane mainly because of safety regulations, but if these designs are any indication of what’s to come, your flight of the future could be more cramped than ever.