An airline pilot reveals why the Boeing 757 is truly unique
Boeing 757 American Airlines
Boeing 757 American Airlines

(American Airlines Boeing 757.Flickr/Aero Icarus)

Twelve years after Boeing discontinued the 757, the long-time 'tweener in the company's lineup is still popular among U.S. airlines.

American, Delta, and United all operate large fleets of the airplane.

Even though the Renton, Washington-based plane maker booked more than 1,000 orders for the jets over its two decades in production, it was never a hot seller.

By the early 2000's, sales of the 757 had all but dried up, and Boeing put the plane out to pasture in 2004.

Although many of the planes are pushing 25 years of service, airlines are hanging onto their 757s. For instance, Delta, who has spent big bucks on a fleet of new jets, recently refurbished the cabins of its aging 757s instead of replacing them with newer planes.

So why are its customer's so loyal? Is the 757 such as good? To get some answers, Business Insider recently spoke with author and Boeing 757 pilot Patrick Smith about the plane.

"There's no denying the 757 is an old plane that was designed in the late 1970s, but the versatility of the plane is remarkable and unmatched," Smith, the author of the book Cockpit Confidential, told Business Insider in an interview. "It's profitable on both short-haul domestic as well as trans-Atlantic routes."

Boeing 757 Delta Airlines
Boeing 757 Delta Airlines

(Delta Boeing 757.REUTERS/Tami Chappell)
During it's production life, the 757 was always a bit of an oddity — a 'tweener of sorts. It's larger and offers greater range than the average narrow body jet, but smaller and cheaper to operate than a wide-body. Boeing and its customers, for many years, didn't quite know how to take full advantage of the plane's capabilities. However, when they did figure it out, it became an integral part of the operators' fleets.

Boeing is currently marketing a new stretched variant of its long-serving 737 — called the MAX 9 — as a potential replacement for the 757. Now, there's talk that Boeing may make the 737 even larger to match get closer to the 757's capacity.

"Boeing is trying to push the 737 as a viable 757 replacement," Smith said, "In some respects it can and in some respects it can't."

For instance, the 737 simply isn't capable of the same kind of engine performance as the 757.

According to Smith, the 737 falls way short of the 757 in terms of runway performance. The 737 requires a much higher takeoff speed and much more runway to get off the ground.

"The 757 can be off the ground in 4,000 ft. and under 140 knots," he told us. However, Smith recounts being in the cockpit jump seat of a 737 as two other pilots were flying. During takeoff, the author noticed that the plane didn't lift off until 160 knots and used up much more runway.