News news, media media, coverage coverage. This summer every major news story seems to have been followed by another major story about how it was covered by journalists, especially TV journalists. The air and the airwaves have been thick with accusation and defensive posturing. No big story seems free of complicating ripples.

For those reasons and others, Friday night's edition of "ABC News Nightline" was a particularly welcome high point for TV news, even for a program that has one of the most admirable and enviable records in television. It was more than a high point. It was a wonder of modern mass communications.

The story was the terrible crash, less than 4 1/2 hours earlier, of Delta Flight 191 at Dallas-Fort Worth International Airport. The crash occurred at 7:05 p.m. eastern time, while "Nightline" anchor Ted Koppel was filling in for Peter Jennings on ABC's "World News Tonight." When he got off the air at 7:30, Koppel and "Nightline" executive producer Richard N. Kaplan agreed that the evening's planned "Nightline" broadcast, on the threat of a baseball strike, should be scuttled and the program devoted to the crash instead.

ABC had no correspondents at that point available near the crash site. This turned out to be more of an advantage than a handicap. The first seven minutes of "Nightline," after the usual Koppel introduction, consisted of unnarrated footage from the scene of the crash, shot by ABC affiliate WFAA in Dallas and brilliantly edited into a riveting montage. What a viewer got from these seven minutes was a more immediate and authentic impression of what the crash was like, and what its effects were on those involved, than a reporter standing in front of the carnage with microphone could possibly have provided. Indeed, it reaffirmed the fact, often overlooked in TV news, that the camera is still the most essential correspondent.

"Leave the bodies where they are," a man with a bullhorn was saying, while firefighters and other rescuers roamed amid the debris with stretchers. The huge tail of the burned L1011 loomed in the background of many shots. A man being loaded into an ambulance was followed (but not harassed) by the film crew, and to the question "What happened?" shouted from off camera, the man replied from inside the ambulance, "We hit a water tower, I think." Then the doors were shut and it sped off.

In later footage shot at St. Paul Hospital, Jay Slusher, another survivor of the crash, was rolled out in a wheelchair by a hospital spokesman who said, "He'd like to make a statement." Slusher's statement included the remark that "I thought we had landed," when the plane in fact had bounced off two cars on a highway near the airport, before hitting a water tank and crashing.

Slusher appeared later in the program, live, to talk to Koppel from Dallas. Koppel's questions were stringently succinct: "Was there in fact an explosion?" "What was the sense aboard the plane as you were coming in?" Slusher's answers and his description of the plane's last moments were reported in front-page newspaper stories the next day.

Koppel's later guests included Patricia Goldman, vice chairman of the National Transportation Safety Board, who was reluctant to comment. After one of Goldman's evasive answers, Koppel said sternly, "Explain that to me. What do you mean?" It's hardly news anymore, but Koppel remains television's reigning Inquisitor General. He's simply the best.

Other elements of the program included a report on the wind shear phenomenon, believed to be a likely cause of the crash. Although much of the report had been aired on a previous "Nightline" two years earlier, reporter James Walker came in to ABC's New York studios to update it. Koppel also interviewed Jim Fry, an able and articulate WFAA reporter at the scene.

This edition of "Nightline" was the very model of a high-tech television newscast, responsive and responsible, illuminating and compelling. There were no wasted motions and no excess words.

From his Washington home yesterday, Koppel praised "Nightline" personnel for reacting so swiftly to such events. "At the risk of sounding self-congratulatory, I think the 'Nightline' production staff has a capability that is unparalleled in taking something like that and in two or three hours putting together a broadcast," Koppel said. "I don't think there's any group in television that can do what they do."

Koppel said he and Kaplan made the decision early in the evening to open the program with unnarrated on-scene footage. He credited longtime ABC News writer and producer Robert LeDonne with assembling the piece. Asked if the footage was aired in that fashion because there was no correspondent available or because it was the best approach for a disaster on this scale, Koppel said, "A little of both." He said the last time the technique was used was in July 1984, after 21 people were killed by a deranged gunman at a fast food restaurant in San Ysidro, Calif.

For Koppel, it was a week of bests and worsts. On Tuesday, he moderated a lengthy "Viewpoint" program aired in the "Nightline" time slot that proved something of a shambles and a squandering of air time. Ostensibly rigorous self-scrutiny about the way TV covered the Beirut hostage crisis, the program quickly degenerated into a meandering apologia, with long and tedious soliloquies by ABC News President Roone Arledge, who tended to hog the spotlight.

Koppel would not concede the "shambles" description yesterday, but did agree the program had been overbooked, with too many guests in too many locations. Overbooking is a television disease spread by nervous and thick-skulled producers. "Yes yes yes, absolutely," he said. "Never never again will we do a program like that with that many different people."

Tonight's "Nightline" will be a hypothetical report on the continuation and conclusion of World War II as it might have occurred had the atom bombs never been dropped on Hiroshima and Nagasaki. It is reminiscent of the 40th-anniversary D-Day "Nightline," which endeavored to cover the invasion of Normandy as "Nightline" might have covered it then. We didn't have "Nightline" then, of course. Friday's superb broadcast was another reminder of how fortunate we are to have it now.