The 757 typically carries 200 to 243 people in a two-cabin configuration, flies as far as 7,200 km and stretches 54 metres.
Boeing is considering the largest-ever narrow-body jetliner to fill a void in the commercial aircraft market left when production of the 757 model ended a decade ago.
Plugging the gap between the 737, Boeing's biggest single-aisle plane, and the smallest 787 Dreamliner is increasingly important for Chicago-based Boeing. Customers like American Airlines have been turning to an Airbus Group SE offering for US transcontinental flying once handled by the 757.
The sweet spot? A new plane that's 20 per cent larger and boasts 20 per cent more range than the 757, the longest narrow-body ever built, said John Wojick, Boeing's chief aircraft salesman. Single-aisle planes are the workhorses of the global airline fleet, and Boeing's deliberations on a 757 successor have been closely followed in the aviation industry.
Airlines are signaling "'What we'd like is an airplane that's substantially larger, will fly significantly farther'" than current Boeing and Airbus narrow-bodies, Wojick said in an interview.
The 757 typically carries 200 to 243 people in a two-cabin configuration, flies as far as 3,900 nautical miles (7,200 kilometres) and stretches as long as 178 feet, 7 inches (54 metres). In the US, carriers have often put the plane on busy transcontinental routes, carrying more passengers than on a 737 while risking fewer unsold seats than with a wide-body.
Developing a single-aisle jet bigger than the 757 does have drawbacks, said Wojick, who spoke before airline executives gathered in Miami this week for the annual meeting of the International Air Transport Association. A new aircraft wouldn't reach the market before the mid-2020s, he said.
Boeing remains unconvinced that sales would be strong enough to support the required multibillion-dollar investment, Wojick said. Then there's the risk of undermining the 737 Max family, upgraded jets that will debut starting in 2017.
It isn't clear whether airlines would pay more for an all-new plane than the $124.4 million list price for Airbus's narrow-body, the A321neo, that has been a popular 757 replacement, Pilarski said. Fuel savings, usually the strongest selling point for a new model, now seem less urgent, he said.
"We know that oil prices are lower, so the advantages of an all-new design are lower," Pilarski said in a telephone interview.
Boeing's Wojick said the quickest and easiest solution to the planemaker's challenge would be to strap extra fuel tanks onto the biggest Max model to create a longer-range version.
"We talked to our customers about would they be interested in a 737 Max 9 with more fuel in it," Wojick said in an interview. "The answer they've come back with is, 'No.'"
Airbus is trying to seize the niche by adding extra fuel capacity to a variant of the A321neo, a plane akin to the Max 9. Air Lease is the initial customer, with an order for 30.
"It was an innovative solution, but stopgap is the right word," said George Hamlin, president of Fairfax, Virginia-based Hamlin Transportation Consulting. "It solves a problem for Airbus and also the people who are going to use it."
Hamlin sees demand growing for a jet holding 200 people, with two aisles to speed boarding and a fuselage broader than the 757 but slimmer than the wide-body 767.
As Boeing and Toulouse, France-based Airbus ponder how to serve that market, new entrants such as Commercial Aircraft of China may try to jump in with just such a model to challenge the traditional duopoly on jetliner sales, he said.