Frequent fliers know all too well: Hell isn't fire and brimstone. It's a coach seat on a seven-hour trans-ocean slog. For decades, airlines have sacrificed passenger comfort in their cattle-class benches to concerns for safety, economy, and ease of maintenance. The result: a cozy metal rack draped in luxuriant, stain-resistant DuraWeave. Talk about flying by the seat of your pants.

Perhaps there's a better way. Virgin Atlantic Airways, with London-based design firm PearsonLloyd, set out in 2003 to create chairs for its economy and "premium economy" sections that feel like, well, chairs--more furniture than machine. Virgin says it has spent $25 million on the project so far, with the new seats set to appear in planes over the next year or so.

Virgin and PearsonLloyd started by reexamining the historical constraints on airplane seating. The first was weight: One reason coach perches feel so spartan is the very real demand that they be light--and with jet-fuel costs at a record high, no airline can afford to add pounds. So the team figured out how to cut the number of components in economy seats by 20%. That let it add new features, such as adjustable lumbar support, while keeping overall weight the same.

The carrier also bucked convention by bringing designers to the party from day one. In the past, engineers mostly ran the seating show--and they put cost and safety above comfort and aesthetics. Not that those engineering concerns aren't vital: "We're designing a chair that has to withstand a 16 g crash test," says Joe Ferry, Virgin's design head. But previously, "it's been left to engineers to create the structure, and then [designers] stitched over the top of it."

Teaming designers with engineers produced creative solutions to old problems, like shifting a support bar so that it could hold the same weight load without sticking into passengers. It also yielded a new manufacturing strategy. Most airline seats are built the way couches are--a basic skeleton covered with upholstery. Virgin designers thought that approach wasted space and made upkeep difficult. So the new seats include replaceable modules that let cleaning crews quickly swap out damaged pieces during a plane's turnaround time: Just rip out the old and Velcro in the new. "Our maintenance guys have a much easier time maintaining the seats, and that ultimately means the passenger gets a comfortable seat," says senior design manager Paul Edwards. And by the way, the seat is thinner--though Virgin won't say how much.

PearsonLloyd then ran hundreds of iterations--computer renderings, scale models, full-size prototypes--in search of a single seat that would fit an infinite range of bodies, says Luke Pearson, cofounder of PearsonLloyd. Sitting down, "one person's head could be two inches higher than the next person's," he says. "Yet when they're standing, they're the same height." Designers responded with a movable headrest and adjustable seat back--each of which created new problems, requiring still more modeling.

What they've produced, in the end, looks a lot like… an airline seat. But it feels noticeably better--almost human, even for us tall guys. In tests since last winter, the seats have received mostly positive flier feedback, Virgin says. Which means that hell may be getting just a bit more livable.