CBS Entertainment yesterday confirmed that Patrick Duffy will return to "Dallas" as . . . Bobby Ewing!!!

Entertainment President B. Donald (Bud) Grant let that particular feline out of the bag last week during a closed-circuit announcement of the CBS fall schedule to affiliates . . .

Yesterday, he told a CBS spokesman in New York that "the big mystery is really how we're going to do it" . . .

Ever since the announcement was made that Duffy was to return to the series on the May 23 season final episode after apparently dying last September in the role of Bobby, both CBS and Lorimar-Telepictures have been silent about his new role, letting the speculators speculate he'd return as an identical twin or something (Duffy even said recently on "The Tonight Show" that he would not return as Bobby) . . .

The word in New York yesterday was that Frank Gifford has decided to sign up again with ABC Sports and Monday Night Football . . .

If true, that throws a spanner into CBS News plans to revamp the "Morning News" on-air lineup for next fall . . .

Insiders say that Executive Director Susan Winston had definitely penciled in Gifford to coanchor the show with an unnamed "West Coast person" . . . although there were serious doubts CBS could come anywhere near Gifford's reported $1 million plus salary at ABC . . .

The Winston Plan would have obviously affected the status of current coanchors Forrest Sawyer and Maria Shriver as well as that of Faith Daniels, whose good work on the "Morning News" has apparently attracted the attention of "CBS Evening News," regardless . . .

Now, however, Winston must go back to the old drawing board and the status of all the incumbents may have changed for the better . . .

Also on the Morning Front, the New York Post's Page 6 reports that Capital Cities/ABC Inc. executives have notified "Good Morning America" host David Hartman -- whose contract with "GMA" is up in September -- that he can stay but must take a 50 percent cut in his $2 million contract and relinquish the unusual editorial control he now has on the show, including the power of hiring and firing his executive producer . . . sk,2

C. Airwaves was unable to reach "GMA" Vice President Phil Beuth for comment on the Post story yesterday . . .

Pat Collins, former WJLA feature reporter, joined Channel 4 yesterday as a general assignment reporter . . .

ABC Fall Schedule

Third-place ABC yesterday announced its fall schedule, calling for 6 1/2 hours of new programming, including four situation comedies, four one-hour dramas and a one-hour ABC News program . . .

In addition, "MacGyver" will move to 8 p.m. Monday, "Perfect Strangers" to 8 on Wednesday and "Spenser: For Hire" to 10 on Saturday . . .

Friday and Saturday nights, owned by CBS and NBC, respectively, last season, will show the biggest changes next fall . . .

Gone from the current schedule are "Hardcastle & McCormick," "The Love Boat," "Benson," "Ripley's Believe It or Not!," "The Fall Guy," "He's the Mayor" and "The Redd Foxx Show" . . .

New to the lineup on Tuesday at 10 will be "Our Kind of Town," with Shelley Hack and Tom Mason as "one of Chicago's most beloved couples," she a newspaper columnist, he "a young entrepreneur on the rise" . . .

On Wednesday at 8:30, the sitcom "Head of the Class" stars Howard Hesseman as the teacher of a high school class of gifted and talented students -- with all kinds of day-to-day growing up problems . . .

Thursday at 8, "Our World" from ABC News "offers a nostalgic look at the special moments in America's past through a blend of scenes from our history with a firsthand recollection of witnesses to the events" . . .

Friday at 9, "The Last Electric Knight" is a sitcom about a "disheveled but appealing bachelor detective" who becomes the guardian of a young martial arts expert. Together they thwart the criminal world" . . .

"Sledge Hammer" at 9:30 Fridays stars David Rasche as a "comedy extension of today's biggest macho man. He makes Dirty Harry and Rambo look like Pee-wee Herman." He also talks to his gun . . .

Also on Friday at 10, "Starman" is an alien who returns to Earth after 14 years and "assumes the body of a free-lance photographer" (I think I've met him) to raise his orphan son . . .

On Saturdays at 8, "Life With Lucy" stars Lucille Ball as a businesswoman who joins her deceased husband's partner in a hardware store -- in order to get away from her crowded household . . .

At 8:30 Saturdays, "The Ellen Burstyn Show" stars you-know-who as a "witty, iconoclastic college professor" who shares her Baltimore brownstone with her mother, her divorced 25-year-old daughter and a grandson . . .

At 9 Saturday, "Cold Steel and Neon" is an hour drama about a widowed police detective whose dangerous occupation is further complicated by the two young children "who are the center of his life . . . which makes him vulnerable" . . .

We'll give you the full ABC schedule tomorrow . . .

Also in the News

"North and South, Book II" completed its six-night run on ABC Sunday after a two-day layoff caused by CBS' domination of Friday night and the low audience levels on Saturday . . .

Thursday night, Part V had a 20.8 national Nielsen rating and a 32 percent audience share . . .

Sunday night, the conclusion averaged a 23.6/36 in Nielsen's 12 major markets (national figures will be out today) . . .

Those were the best overnight figures of the week for "North and South," and included a 28.4/45 on Channel 7 here, as Washington, alone of the big markets, continued to be fascinated with the mini-series . . .

It's been something like seven years since C-Span began its remarkable coverage of the House of Representatives for cable systems around the country . . .

Well, as of 6 a.m. yesterday, House members are finally able to see daily C-Span coverage of the House on their own Channel 2 . . .

The Senate, which began a test of its sessions on May 1 -- which will be made available to C-Span audiences for a six-week trial starting June 2 -- can already see itself on the internal TV system . . .

C-Spanners do have the audio portion of the Senate sessions now available on some cable systems . . .

President Reagan's commencement address to the students of Holmes High School in Edenton, N.C., today will be carried live on PBS, including Channel 26 here, starting at 1 p.m. . . .

On the other hand, Joan Rivers has canceled tonight's appearance on "The David Letterman Show," prompting producer Barry Sand to issue a statement saying "we are very sorry that she's canceled . . . and hope we can reset the booking soon" . . .

Translated: Letterman, considered a top candidate to replace Johnny Carson on "The Tonight Show," and not all that eager to offend Mr. C., is probably happy as a clam that the woman who owes Johnny for her break and is now set to compete with him for Fox Broadcasting, won't show up . . .

And Finally

A Purely Personal Opinion from the desk of Captain Airwaves . . . who yields to no one in his respect for Claude Akins . . .

"Frankly, Claude, your 'Ouch!' on behalf of Poli-Grip doesn't hold a sesame seed to the late Lloyd Nolan's 'Owwww-ch!' Now that was an 'Ouch!' (Signed) Yours truly, Captain Airwaves" . . .