The airline has replaced the roomy, comfortable Airbuses from the former Northwest Airlines with older, lower-end planes.
Frequent fliers at Minneapolis-St. Paul International Airport notice it: more cramped planes on some domestic routes, less entertainment on some flights to Europe.
The complaints deal largely with a decision by Delta Air Lines to replace Airbuses that Northwest Airlines flew at MSP with Boeing or McDonnell Douglas jets, many of them older.
"I'm on MDs all the time now," said Dan Boivin, chairman of the Metropolitan Airports Commission, the government agency that oversees Minneapolis-St. Paul airport. "I don't like them as much. I miss Airbuses."
Many of those Airbuses now fly out of Delta's home base in Atlanta and from Salt Lake City International Airport.
Some frequent fliers worry what a downgrade could mean for the Twin Cities.
"If we have the lower end of the planes ... it feels like you're a little bit more in the minor leagues," said airport commissioner Rick King.
Delta defends the switch, citing Minnesota's central location.
"We always work to deploy the most efficient aircraft to each route, which is critical to the success of our hub at MSP," said Delta spokesman Trebor Banstetter.
As for comfort, he said Delta "has begun a nose-to-tail cabin refurbishment" of its Boeing 767 aircraft flown from MSP to Europe. It will include "in-seat video in every seat" like Airbuses that fly overseas, and "larger and modern overhead bins."
International departures on Boeings from MSP to Europe and Japan tripled from 2008 to last year, according to OAG, a British aviation analysis firm that compiled trends for the Star Tribune. Meanwhile, international flights on Airbus 330s from MSP were cut in half.
During the same time, Delta departures from MSP to U.S. cities on two popular types of smaller Airbuses -- the A319 and the A320 -- also dropped by half. Domestic departures from MSP on two models of McDonnell Douglas jets -- MD-88 and MD-90 -- increased dramatically. Overall, Banstetter noted, there are still more Airbuses than McDonnell Douglas planes at MSP
Age and noise
Delta is one of the world's largest airlines and took over Northwest's role as the dominant carrier at MSP, where it flew about 80 percent of nearly 200,000 departures in 2011.
The MD-88s have been dubbed "Mad Dogs" in some aviation circles -- not always affectionately.
One consumer website, Seatguru.com, complained about noise and legroom near the rear of the cabin.
"Due to rear-mounted engines, the aircraft is noisiest towards the back and seats behind the rear exits should be avoided," the website advised travelers.
Airbuses, whose engines are mounted under the wings, were spared a similar critique.
Data released by the Federal Aviation Administration in 2010 and more recently by the Metropolitan Airports Commission confirm that the MD-88 is generally louder on takeoff than the A319 or A320.
Many older planes tend to be louder, and Delta's fleet of MD-88s averages 21.5 years compared to 9.9 years for its A319 fleet and 16.8 years for its A320s.
In recent months, Delta has decreased MD-88 flights and increased those of the newer MD-90s, buying some secondhand from Japan Airlines. Delta's MD-90s have an average age of 15.1 years and quieter engines similar to those on the two models of Airbuses.
Despite the improvements, the MD-90 also has attracted critics since its rapid expansion at MSP. Twin Cities airline buff Marc Friedman wrote in his Examiner.com blog that tight seating on one MD-90 flight "made it impossible for me to open my laptop computer when the passenger seated in front of me reclined his seat. ... The passenger seated next to me ... had given up trying to use his laptop."
"Please, Delta Air Lines. Give us back our Airbus A319 and A320 flights."
King, who is a frequent flier, said the Airbuses are "infinitely more comfortable" than the McDonnell Douglas planes.
For one thing, some of the seats on Delta's domestic Airbuses have an extra inch of legroom than seats on its MD-90s.
Passengers also point out that one side of the overhead compartments of the McDonnell Douglas is shallower than those on Airbuses, requiring bags to be stored horizontally and filling up more quickly.
"People come on the plane with their bag and it's filled," King said. The luggage then needs to be checked at the gate.
Delta: Move makes sense
Delta says shifting McDonnell Douglas planes to MSP makes sense because its location in the center of the nation makes it more suitable for the shorter range of the aircraft.
"From MSP, the MD-88s and 90s can reach almost the entire U.S. and Canada, while the greater range of the Airbus aircraft allow them to fly from Salt Lake City to the East Coast," said Delta spokesman Banstetter.
He said Delta has nearly phased out the DC9, a domestic workhorse that is even older and louder than the MD-88. That trend began under Northwest and helped shrink the acres of excessive noise in neighborhoods around MSP.
Boivin said he will meet with Delta this month and ask for more details on its fleet plans as well as press for more nonstop international flights.
"Every indication we have had from Delta leaders is that the airline remains fully committed to its MSP hub, and nothing they are doing here suggests otherwise," said airport spokesman Patrick Hogan. He said domestic Airbus flights have grown in recent months, along with a lesser increase in McDonnell Douglas flights.
For long distances, the differences between the Airbus 330s and Boeing 767s can be subtle but significant. "For the average person, they're not as comfortable," Timothy Kehoe, an economics professor at the University of Minnesota, said about the 767s.
Delta's coach seats on 767s from MSP to Amsterdam have lacked in-seat personal entertainment, unlike Airbus flights. It can make a difference on an eight-hour flight.
"It makes the trip go so much faster," Boivin said.
Delta's Airbus 330s are less than seven years old on average, while its models of 767s range from 11 to 21 years old.
King, chief operating officer for technology at Thomson Reuters who often flies overseas, worries that future passengers might trade a nonstop from MSP to Europe for a one-stop flight with a similar fare that is more comfortable.
"That doesn't load up your planes for the direct international flights and support the fact that you want to keep the direct international flights going," he said.
Delta has direct flights from MSP to London on another version of 767 that offers personal TVs in coach, as do its Boeing 777 flights to Tokyo and Airbuses to Paris. The airline said it is moving ahead on refurbishing all of its 767s.
"The entire fleet will be completed by the end of 2013, and customers are already beginning to see these 'like new' aircraft as they are deployed," Banstetter said.
Pat Doyle • 612-673-4504