The Chicago Bears made it look easy in Super Bowl XX and Super Bowl XX made it look easy for NBC last week as the season front-runner whipped CBS and ABC.

For the week ending Super Sunday 1986, NBC had a 21.2 Nielsen rating and a 32 percent audience share, compared with a 16.0/24 for CBS and a 14.4/22 for ABC . . .

The Bears-Patriots game tied the Dallas-Denver matchup in Super Bowl XII as the third-highest-rated SB of them all . . .

Among the more modest achievements last week, the Bob Hope special on NBC was 23rd, ABC's "Prince of Bel Air" was 28th, CBS' new "Mary" was 38th and "Foley Square" was 41st . . .

"Miss Teen USA" on CBS tied for 42d, ABC's "The Redd Foxx Show" was 45th, NBC's "Blacke's Magic" was 46th and the Muppets' 30th anniversary on CBS was 51st . . .

The NBC special honoring Dr. Martin Luther King Jr. was 55th, an NBC News special on AIDS tied for 57th and Bill Moyers' highly praised CBS documentary on black families was 64th . . .

Also in the Newssw,-2 sk,2 ld,10 In New York yesterday, by the time the continuous coverage of the shuttle tragedy had drawn into the late afternoon, ABC had recorded 1,200 telephone calls -- 80 percent of them from viewers complaining the soap operas weren't on the air . . .

The Cable News Network, which routinely covers shuttle launches live from Florida, was on the air with "a mix" of its own camera coverage and the NASA "pool" coverage when Challenger lifted off at 11:39 a.m. CNN viewers saw it happen, live . . .

On the West Coast, audiences for NBC's "Today" show saw live coverage of the launch starting about five seconds after Challenger had left its pad. They, too, saw it happen live, as KNBC reporter Kent Shockneck described the scene . . .

In New York, technicians were routinely watching the NASA pool feed at NBC, where, as at ABC and CBS, footage is examined for use later in the evening on the network news program . . .

Word of the explosion brought East Coast "Today" news anchor John Palmer running and the network went on the air from New York at 11:43 a.m. . . .

Tom Brokaw was in Washington attending a White House briefing on President Reagan's State of the Union message when he got the news. He raced to the NBC bureau out on Nebraska Avenue and joined Palmer on the air at 12:11 p.m. . . .

Brokaw was still on the air after 5 p.m., following President Reagan's brief address on the tragedy . . .

NBC, like ABC and CBS, scheduled a one-hour special on the tragedy for 10 last night . . .

Dan Rather was in his office at CBS News in New York yesterday when members of the special events unit, watching the NASA feed, saw the explosion. Rather raced to the "flash studio" down the hall and got on the air at 11:45 a.m., without his customary contact lenses or makeup. He anchored the coverage continuously until 5:15 . . .

CBS also had footage from WNEV, its affiliate in Boston, which had a crew at Cape Canaveral to follow the parents of Christa McAuliffe, the Concord, N.H., schoolteacher who was on the doomed shuttle. Their cameras caught their horrified reaction when the "perfect launch" turned into a nightmare . . .

ABC anchor Peter Jennings was at the White House briefing, too, when the monitors at the ABC News bureau here recorded the explosion. Early news anchor Steve Bell, who was still in the studio, went on the air for the network at 11:43 a.m. and was joined by Jennings at 12:04 p.m. Jennings took over the major anchor role for the afternoon and, like Rather and Brokaw, broadcast until Mr. Reagan's 5 p.m. address had been aired . . .

In addition to the special at 10 p.m., ABC planned an extended edition of "Nightline" . . .

More Managementsw,-2 sk,2 ld,10 Changes were announced by Capital Cities/ABC Inc. yesterday as top executives, meeting in Phoenix, restructured the owned-television stations division . . .

Lawrence J. Pollock, formerly president and general manager of WPVI in Philadelphia, was named president of Capital Cities/ABC Inc. owned TV stations-East . . .

He will be in charge of ABC stations WABC in New York and WLS in Chicago and the Cap Cities stations WTVD in Raleigh-Durham and WPVI . . .

Kenneth Johnson, formerly president of KTRK in Houston, was named president of Capital Cities/ABC Inc. owned TV stations-West, in charge of ABC's KABC in Los Angeles and KGO in San Francisco and Cap Cities' KFSN in Fresno, Calif., and KTRK . . .

The eight owned stations give the network 24.39 percent coverage of U.S. TV homes, just below the 25 percent limit for network-owned stations under FCC regulations . . .

Michael P. Mallardi, president of the broadcasting division and senior vice president of Capital Cities/ABC Inc. announced the changes. On Monday, Dennis Swanson, who had been president of ABC's owned TV stations division, was named president of ABC Sports, succeeding Roone Arledge, who was named group president of ABC News and Sports . . .

The three-hour "American Music Awards" won Monday night for ABC, averaging a 20.5 Nielsen rating and a 30 percent audience share. The regular CBS lineup averaged 18.0/26 . . . while the NBC combination of "A Masterpiece of Murder" and "American Almanac" averaged 15.2/22 . . .

"Almanac" did only a 10.1/16 during its hour. That included a 9.1/14 on Channel 4 here. The 11 p.m. news on Four, with Jim Vance aboard for the first time, did a 10.3/20 . . .

Incidentally, Four's switchboard recorded 150 favorable phone calls Monday night from viewers commenting on Vance's return to the air after a long absence . . .

Speaking of phone calls, Channel 9 received some 140 phone calls Monday night from viewers complaining about the "America: You're Too Young To Die" syndicated special at 8 p.m., which preempted "Scarecrow and Mrs. King" . . .

Twenty viewers called to approve the broadcast . . .

A station spokesman yesterday said another 200 viewers had called Tuesday, about evenly divided between for and against. Most callers, he said, complained that the religion hour was not the "patriotic" show that they had been led to expect . . .

The program was sponsored by the Arthur S. DeMoss Foundation, publishers of "Power for Living" . . .