It's the end of an era for American Airlines' Super 80 planes. The carrier is flying its last revenue flight of the classic McDonnell Douglas MD-80 Wednesday.

The aircraft, also called Super 80, has been an American Airlines workhorse since 1983 when the airline operated three of them.

By 2003, the airline had 362 crisscrossing the sky -- about a third of all the MD-80s ever produced, according to American Airlines.

The MD-80's final American Airlines revenue flight, AA80, was scheduled to depart from Dallas/Fort Worth International Airport at 9 a.m. and arrive at Chicago O'Hare around 11:30 a.m.

Fans of the plane, nicknamed Mad Dog, took to Twitter on Wednesday morning to share their memories. "Goodbye maddog! Thank you for your fabulous rides, silver shiny reflections, and captivating presence!" wrote Christine Phillips.

Most of American's remaining 26 MD-80s are retiring to Roswell, New Mexico. The plane operating AA80 will ferry to Roswell from Chicago after the flight.

It marks the end of the ride for the shiny aluminum-liveried domestic workhorse at American Airlines. The MD-80 was one of the most fuel-efficient aircraft in the sky when it was first introduced.

American is modernizing its fleet with newer, more fuel-efficient aircraft.

"Since 2013, American has invested more than $28 billion in its product and people and now flies the youngest fleet among US network carriers," the airline said in a press release.

Delta Air Lines still operates MD-88s, and MD-80s are still in operation overseas, so it's not a final goodbye for the Super 80.