(This story was updated to accurately reflect the most current information.)

LOUISVILLE, KY – The plane at the center of a deadly Kentucky crash has been a workhorse in the cargo industry for years, but it had gained a reputation as an aircraft that was behind the times.

The MD-11 used to carry passengers, but that ceased over a decade ago, primarily due to its high fuel and maintenance costs, experts told USA TODAY. Its tenure as a cargo plane is also likely nearing an end for the same reasons.

“The model was antiquated by the time it came out – except, of course, for cargo. It’s a workhorse,” Mary Schiavo, a former U.S. Department of Transportation Inspector General, said in a phone interview. It's a "big, heavy" aircraft, Schiavo said.

While the jet has had a number of safety incidents, its reputation and fate in the aviation industry has been dominated by economic woes.

“It’s economics. The airplanes are an older design. They’re not as fuel efficient. They require more maintenance than later generation airplanes,” said John Cox, the founder of Safety Operating Systems and the longtime author of USA TODAY's “Ask the Captain” column.

As of early 2025, there are about 82 active MD-11 freighters flying for three main companies: FedEx Express, UPS Airlines, and Western Global Airlines, according to Aerospace Global News.

FedEx currently operates the largest active fleet and both it and UPS have said they are phasing out MD-11s in favor of newer planes.

The cause of the Kentucky crash wasn't immediately clear, and 28 members of the National Transportation Safety Board arrived in Louisville on Wednesday to investigate alongside the Federal Aviation Administration.

Why did passenger airlines stop flying MD-11s?

The final passenger MD-11 was retired by KLM in 2014. At that time, KLM said that "the aircraft was expensive to maintain, had high fuel consumption, and spare parts were hard to find," according to a release from KLM.

Aviation experts told USA TODAY that MD-11s were largely phased out of use for economic reasons, with carriers favoring more fuel-efficient, modern aircraft.

“In general, the economics of an aircraft dictates how long they keep it in service,” said Ross “Rusty” Aimer, the CEO of Aero Consulting Experts and a longtime United Airlines pilot.

Additionally, MD-11s were known among pilots as a difficult aircraft to fly, Aimer said.

“It had kind of a reputation of being a hard airplane to land,” he said.

Aviation expert Daniel Rose, an attorney with Kreindler & Kreindler, in an interview with USA TODAY, said MD-11s were retired from passenger service because they were too expensive to operate, both in terms of fuel and maintenance costs.

Aviation attorney Ladd Sanger, whose work has included crash litigation, pointed to the age of the surviving MD-11 fleet as well as a reason why they are being retired. “Aircraft have a useful life – and these aircraft are all 30 plus years old, some 40 years old, and they’re nearing their life,” he said.

McDonnell Douglas built only 200 aircraft between 1998-2000 before discontinuing the MD-11, according to simpleflying.com.

How often are MD-11s involved in incidents?

A National Transportation Safety Board database lists only two other critical incidents in the past decade involving McDonnell Douglas MD-11 aircraft like the one that crashed in Louisville.

Both were operated by UPS, according to information on the NTSB’s Aviation Accident and Incident Data System.

In 2016, one of the tri-engine planes operated by UPS had a “rejected takeoff” at Seoul, South Korea’s Incheon International Airport. Injuries were listed as minor, although details in the NTSB database report are very limited.

A Korean language report from South Korea’s Aviation and Railway Accident Investigation Board contains pictures showing a UPS MD-11 nose-down in the grass past the end of a runway.

More recently, in 2021, a UPS MD-11 that had departed Louisville experienced a tailstrike upon landing at Phoenix Sky Harbor International Airport. However, according to the NTSB database report, the flight crew was able to take back off and return for an “uneventful landing.”

The NTSB database report said the plane was “substantially damaged” with later inspections showing damage to the lower aft fuselage and aft pressure bulkhead.

Both of these events were characterized as “accidents,” terminology the NTSB database defines as “an event where there was 100% hull loss of the aircraft or there was a fatality.”

MD-11s have also been involved in several fatal accidents, the most recently coming in November 2009, when an Avient Aviation MD-11 crashed on takeoff from Shanghai, China, killing three.

Earlier that year, a Fedex MD-11 crashed while landing at Tokyo, Japan’s Narita International Airport, killing the plane’s two pilots.

(This story was updated to add new information)

Contributing: Thao Nguyen, Jeanine Santucci, Caroline Neal, USA TODAY

This article originally appeared on USA TODAY: Crashed UPS jet was part of an aging fleet with an expensive reputation

Reporting by Josh Wood, Doyle Rice, Olivia Evans and Matthew Glowicki, USA TODAY / USA TODAY

USA TODAY Network via Reuters Connect