Delta Air Lines’ MD-88 and MD-90 aircraft were noisy, aging and nearing the end of their usefulness before the coronavirus outbreak.

But the pandemic sped up the retirement of the "Mad Dog" jets, which took their final flights Tuesday to an airplane boneyard.

Among the pilots, plane enthusiasts and the airline that depended on them, there's a wistful respect for the workhorse aircraft that carried travelers to and from Atlanta and other U.S. cities for decades.

MD-88s and MD-90s flew nearly half of Delta’s flights in Atlanta as recently as 2014.

The last of the MD-88s touched down as Flight 88 at Hartsfield-Jackson International at about 10 a.m. Tuesday from Washington Dulles, greeted with a water cannon salute and applause from pilots and aviation geeks who gazed through the windows of Concourse A. The retiring jets took off for Blytheville, Arkansas, where parts may be salvaged before the aircraft are demolished.

For MD-90s, the retirement from Delta's fleet marks the end of the line worldwide. While there are some MD-88s in use overseas, no other U.S. airline uses them for regular passenger flights.

Kevin Angueira, an 18-year old aviation enthusiast who took the final MD-88 flight into Atlanta, said it’s the loudness of the engines that distinguishes it.

“Just the noise from it. It’s very special,” Angueira said. “It’s always great to experience an old plane.”

Other more advanced, new generation planes are quieter. But “this plane had character,” said Justin Cederholm, who was on Flight 90 from Houston to Atlanta, the final MD-90 excursion. “These still creak and they’re loud. You know you’re flying.”

Atlanta-based Delta previously planned to retire its 149-seat MD-88s at the end of the year. But, after travel plummeted due to the COVID-19 crisis, it sped up the plan, parked half its fleet and also will retire its Boeing 777s.

The cost to keep the older planes running was increasing, and retiring them allows the company to save money on spare parts, said Delta chief financial officer Paul Jacobson.

Delta was the launch customer for the 158-seat MD-90. In 2008, as the airline struggled to recover from Chapter 11 bankruptcy and merged with Northwest Airlines, adding used MD-90s to its fleet allowed Delta to pay down its debt and position for a recovery.

Some of the retiring jets are around 30 years old. Delta started flying the MD-88s in 1988 and the MD-90s in 1995.

Carl Nordin, the captain at the controls of the final MD-88 flight, is sentimental about the plane he has flown for 18 years, calling the send-off “emotional.” But, with Delta moving to a more modern fleet and shifting its strategy due to the downturn, he said, “It’s also a reality.”