Delta Air Lines, the dom­i­nant com­mer­cial car­ri­er in the Twin Cities, an­nounced Wednes­day that it is over­haul­ing the in­te­ri­or of many aircraft in its domestic fleet, adding space for car­ry-on bags and gadgets.

The Atlanta-based air­line said the im­prove­ments will be phased in through 2016 at a cost of more than $770 mil­lion.

A­mong the en­hance­ments, de­pend­ent on air­craft model: lar­ger over­head bins, roomi­er bath­rooms, e­lec­tri­cal out­lets at every seat, in-seat vid­e­o screens, im­proved cab­in light­ing and seats with ad­just­a­ble head­rests.

The changes match those Delta has made in recent years on its international fleet and bring its entire fleet closer to the accommodation standards of airlines such as Singapore, Cathay Pacific and Qatar, which have industry-leading reputations for comfort and service although they have a smaller number of planes.

Delta spokes­man Paul Skrbec said that while he can "nev­er say nev­er," the air­line has no plans to cre­ate fees for any of these improvements.

"The fo­cus is not doing things to in­crease fees at this point," Skrbec said.

Since air­lines first be­gan char­ging for checked bags as a rev­e­nue source, many pas­sen­gers have coun­tered by bring­ing as much as pos­si­ble on the air­craft. This strategy has strained de­mand on the over­head bin space and at times re­sul­ted in pas­sen­gers be­ing re­buffed mo­ments be­fore take­off be­cause their car­ry-on piec­es were deemed too large.

Delta said it will soon be­come "the first car­ri­er in North America to in­stall the new bin sys­tem, which will increase pas­sen­ger car­ry-on bag­gage capacity by more than 50 percent."

Skrbec said that pas­sen­ger feed­back has been strong­est for a place to plug in.

"Gen­er­al­ly, our cus­tom­ers have been very clear that hav­ing ac­cess to pow­er has been a pri­or­i­ty for them," he said.

Twin Cities-based air­line an­a­lyst Terry Trippler, of www.theplanerules.com, says Delta's an­nounce­ment is "a di­rect re­sult of Delta realizing there is a third strong glo­bal airline now" a­mong its com­pe­ti­tion, with the merg­er of American and US Airways last month. United is the oth­er ri­val.

Giv­en that the fu­se­lage of each air­craft can't change, the add­ed space for over­head bins and bathrooms had to be found some­where in the in­te­ri­or. Skrbec said the gal­ley areas will be small­er but will make for a more ef­fi­cient workspace for flight at­tend­ants.

He add­ed that some­thing seem­ing­ly as mi­nor as going from a "hard wall" be­tween first class and ec­on­omy to a "soft wall" also gave Delta some space to use.

Glen Hauenstein, Delta's chief rev­e­nue of­fi­cer, said in a state­ment ac­com­pa­ny­ing Wednes­day's an­nounce­ment, "We're con­tinu­ing to make smart long-term in­vest­ments in our pro­ducts and ser­vices to meet the ex­pec­ta­tions of our cus­tom­ers."

Paul Walsh • 612-673-4482