A Delta Air Lines flight returned to New York JFK Airport (JFK) on Thursday morning after its pilots reported a cabin pressurization problem. Flight DL791, operated by a Boeing 757-200, had been headed to Phoenix Sky Harbor International Airport (PHX) with 155 passengers and six crew members onboard when the crew declared an emergency and turned back toward New York.

The incident puts renewed attention on a Boeing type that remains an important part of Delta’s fleet, despite rapidly approaching the end of its career. As of June 30, Delta still had 75 Boeing 757-200s and 16 higher-capacity Boeing 757-300s, but the -200s are already more than 28 years old on average, nearly double the average age of Delta’s entire mainline fleet. The carrier has already begun withdrawing individual 757-200s as newer narrowbodies arrive.

Flight DL791 Returned To JFK

Credit: Markus Mainka | Shutterstock

CBS News reports that DL791 departed JFK shortly before 8:00 AM for a roughly five-hour flight to Phoenix, but was forced to return due to a cabin pressurization issue. Delta said the pilots declared an emergency in order to receive priority handling from air traffic control, and the aircraft landed shortly after 10:20 AM. There were no reported injuries.

Delta said the 757 was handed over to its maintenance teams for evaluation after landing, while the Federal Aviation Administration (FAA) said it would investigate the incident. In a statement later in the day, the carrier explained the circumstances, and apologized to those onboard for the disruption:

“The flight crew of Delta Flight 791 from New York-JFK to Phoenix followed standard procedures and returned to JFK following a cabin pressurization issue. The flight landed safely, and we apologize to our customers for the delay in their travels.”

Notably, the incident came just four days after another Delta aircraft experienced a pressurization problem. On September 6, DL2311 was traveling from Los Angeles International Airport (LAX) to Salt Lake City International Airport (SLC) when oxygen masks deployed aboard the Boeing 737-900ER. People reported that the aircraft descended from 36,000 feet to 9,000 feet in less than ten minutes and diverted safely to Las Vegas with 174 passengers and six crew onboard.

Pressurization problems can affect aircraft of any age: Delta’s 737-900ERs average just 10.5 years. Its 757-200s, however, average almost three times that, and the veteran type has been involved in an increasing number of technical incidents as it moves deeper into its fourth decade of airline service.

Delta’s 757-200s Average More Than 28 Years Old

Credit: Markus Mainka | Shutterstock

Delta remains heavily reliant on the 757, operating 91 examples across the -200 and -300 variants as of June 30, despite Boeing ending production of the type more than two decades ago. Its 75 757-200s average 28.2 years, while the 16 757-300s are somewhat younger at an average of 23.4 years. Of course, some individual aircraft are considerably older, and a 32-year-old 757-200 made headlines back in 2024 when one of its nose wheels separated while it was lining up for departure from Hartsfield-Jackson Atlanta International Airport (ATL).

Today’s incident also joins several other technical events involving Delta’s 757 fleet during the past two years. They range from pressurization and engine problems to cockpit smoke and a rejected takeoff, although the circumstances and severity differ significantly between events.

There is no evidence that the age of DL791 caused Thursday’s problem, nor should a collection of unrelated incidents be interpreted as evidence that Delta’s 757 fleet is unsafe. The FAA specifically requires aging Part 121 aircraft to undergo additional inspections and records reviews after their 14th year in service, designed to ensure maintenance of age-sensitive structures and components remains adequate and timely. Delta TechOps is also a world-leading facility with deep experience at maintaining older aircraft. However, it is noteworthy that one of the oldest types in the fleet appears to be more prone to issues such as pressurization.

Delta has kept its 757s for so long because they remain extremely useful aircraft. The type combines substantial capacity with strong runway performance and enough range for domestic, Hawaiian, and thinner transatlantic services. Delta has even used 199-seat 757-200s for proposed international routes such as Boston-Mexico City. Some premium-configured aircraft even feature the carrier’s lie-flat Delta One seats. However, the curtain is beginning to fall on the storied history of the type at Delta.

The Airbus A321neo Is Taking Over

Credit: Avi Johnson | Shutterstock

Delta is now gradually shrinking the 757 fleet. Its regulatory filings show the number of 757-200s falling from 100 in June 2022 to 75 in June 2026, with five aircraft having left in the past year. Meanwhile, the incoming Airbus A321neo fleet has been moving in the opposite direction.

Delta has been unusually explicit about what comes next. At its 2023 Investor Day, the airline placed the 757-200 directly alongside the A321neo as its next-generation replacement, estimating around 10% lower seat costs, 13 more premium seats, and an additional $4-5 million in annual contribution per replacement aircraft. Delta now has 103 A321neos operating and has 86 on firm order after it exercised options for 34 aircraft earlier this year, and also retains further options for 36 additional A321neos.

The A321neo will not shoulder the entire 757 replacement burden. Delta also has commitments for 100 Boeing 737 MAX 10s plus 30 options, giving it another high-capacity, high-premium narrowbody for domestic flying once the type enters service. Meanwhile, the carrier continues investing in efficiency improvements and newer aircraft as part of a broader effort to reduce operating costs and gradually replace less-efficient jets.

There will not, however, be a single moment when one aircraft neatly replaces every job performed by the 757. Its unusual combination of performance, range and capacity explains why Delta has retained the type for decades. Even its specialized VIP 757 fleet is now beginning the transition: the first of up to 14 specially configured A321neos arrived this summer to begin replacing 11 aging 757-200s used for NBA and other charter flying. Thursday’s return to JFK therefore comes as Delta increasingly finds newer aircraft for the many roles its “flying pencil” has performed.