A few walk around quietly. Some are reading, some working. Others have sound-dampening headsets on. "I look forward to it because I get to read and don't have to answer the phone," Diminich says. "You have 12 hours -- sometimes 14 -- all to yourself."
The seats on the Boeing 777ER are typical of trans-oceanic flights; slightly bigger than domestic seats, but not first-class size.
Down the coach aisle, passengers can get a peek at the lucky business-class and, beyond them, first-class passengers who get lie-flat seats, double the menu options and handheld personal entertainment devices that offer a choice among 20 video titles.
Some risks for the industry
International routes have become more important to U.S. carriers in recent years because they are more profitable, and competition isn't as stiff as it is on domestic flights. For American, 35.8% of its mainline capacity through July, measured in available seat miles, is flying to international destinations. That number has steadily been rising since 2003, when 29.4% of the carrier's capacity was committed to international routes, according to numbers provided by the airline.
Both India and China are "emerging markets," says American spokesman Tim Wagner. "We see a lot of opportunity there right now."
Airplane manufacturers, too, see growth. Both Boeing and Airbus have jet designs that are set to hit the market during the next few years. The Airbus A380 is a superjumbo model that will carry upward of 500 passengers and have a range of 8,800 miles. The Boeing 787 "Dreamliner" will be smaller -- carrying 200 to 300 passengers -- but will have a range of about 8,500 miles. Both jets are expected to enter commercial service by 2008.
And Airbus plans to roll out the A350XWB, a competing model to Boeing's 787, by early next decade.
But at some point, any benefits of the ultra-long-haul flights may be overruled by practicality, say some aviation experts.
"You're putting people in a metal tube for 17 hours," says Henry Harteveldt, chief travel analyst at Forrester Research. "You have to consider issues like passenger comfort. If you don't take care of that, people aren't going to buy the product."
Some risks for passengers
Of some concern to endurance fliers is a condition known as deep vein thrombosis (DVT), where blood clots form in people who sit still for long periods of time. Those clots can travel to the lungs and cause death.
"All (airline) passengers are at some risk of developing DVT on long-haul flights, although the risk for most is low," says Pan Ganguly, director of the Thrombosis and Hemostasis Program at the National Heart, Lung, and Blood Institute in Bethesda, Md.
Experts advise airline passengers to be sure they get up from their seats, stretch and walk around many times throughout the flight. And flight attendants on the Chicago-India flight encourage passengers to do just that.
Still, boredom and ennui are most passengers' biggest worries.
Robins of Austin, visiting his wife who's working on a months-long contract in New Delhi, has read a book, watched a movie, eaten dinner and taken a four-hour nap.
But "somewhere over Iceland or Moscow," he realized he still had six more hours to go before the plane landed.
"That's when it really started to seem like: 'I'm ready to get off the plane!'"