Everyone wants to fly longer, it seems. New aircraft and engine technologies are making ultra-long-haul flights feasible with widebodies like the Airbus A350 and Boeing 787.

These new direct international flights are truly long. Singapore Airlines is doing nonstops of around 19 hours between Singapore and New York Newark. Qantas is planning 20-hour flights from Sydney to London, New York and other cities.

Singapore Airlines is targeting the premium passenger with its US flights, equipping its A350s with a cabin that is all-business-class and premium economy. Chances are that ultra-long-haul international flights will hold most appeal to the business traveler—giving airlines that operate them a competitive edge in the premium market—but nonstops, even at 20 hours, should also attract leisure travelers.

From a revenue standpoint, airlines need to be highly selective about which routes make sense for ultra-long nonstop operations. There’s a history of airlines, albeit with previous generation, less fuel-efficient aircraft, failing to make such routes financially viable. Even with new-technology aircraft, a nonstop route loses the feed and potential additional revenue that a connecting flight provides.

But entering these markets is about more than technology. On a 20-hour nonstop, an aircraft really becomes a hotel room—without the room. And the airline truly becomes a hospitality provider, but one that doesn’t offer a lobby, restaurants, gyms, bars and other facilities that allow the traveler to enjoy his or her stay beyond being strapped in a seat or bed and waiting for the next meal to be plopped on the tray table.

Sadly, the truth is that most airlines are not hospitality providers first and foremost. We all know those airlines that, year after year, have a reputation for excellent customer service. Fortunately, it’s mostly those airlines that are launching these new ultra-long flights.

But if they gain premium market share as a result of these new services, you can bet other airlines less-equipped to provide hospitality will follow. Qantas, which is embarked on its Project Sunrise ultra-long-haul planning, is showing the way. It is fully researching the effect of very long flights on passengers and crews, bringing in medical and other experts, and operating test runs. Given that Qantas, by virtue of its location, is historically experienced on long-haul operations, other airlines need to be at least as thorough and doubly prepared.

Excellent crews; good food and lots of snacks; reliable Wi-Fi and plentiful IFE choices; decent amenities for everyone—not just those with lie-flat business seats—are not just nice-to-haves when you, and possibly your children, have nowhere to go for 20 hours. They are essential, and they are just the beginning.

Airlines with aspirations for longer legs should follow Qantas’ example and do their homework well before they post fares.