It's 7 a.m. and still dark when Dan Rosenson pulls on the throttle of his Cessna 172. But just as it begins to rock and buck as if it's eager to get into the sky, the wingtip and nose lights of a commercial jet pop out of the blackness ahead of him on the National Airport runway.

For a moment, it looks like a traffic jam of sorts in the offing. But not to worry: Rosenson is one of the Washington area's biggest experts at how to avoid tie-ups, so he deftly obtains clearance from the control tower and takes off.

Rosenson, WMAL-AM's airborne commuter traffic reporter, is one of three such reporters for Washington area radio stations. Along with WASH-FM's Walt Starling and WTOP-AM's Bob Marbourg, he prowls the morning and afternoon skies to report live on rush hour tangles that bedevil commuters, making up to four broadcasts an hour.

From their airborne perches at about 1,200 feet, they advise commuters on accidents, closed lanes, weather hazards and other annoyances commuters face, all while keeping an eye open for obstacles in the air and mechanical problems with their planes.

Those dangers are real: Crashes have claimed the lives of some colleagues around the country, including the nation's first, former Army captain Max Schumacher, who flew a helicopter while broadcasting for a Los Angeles station in the late 1950s.

The programs cost each local station more than $100,000 a year today, but airborne traffic reporters are a bonus, station managers said. "Walt's a very important part of what we do," said Earl Murton, sales manager at WASH. Starling appeals to commuters and, Murton said, "radio is a very effective in-car medium."

WMAL's Rosenson, 51, was Washington's first airborne reporter, having taken to the air 17 years ago on WWDC-AM (DC-101).

"I watched them build the Metro system. I watched the first hole being dug," he said. "I've watched the city change, highways built and new buildings going up. From that standpoint it's been fascinating."

He also enjoys his role as "Captain Dan, the traffic advocate."

"I like to look at some of the controversial aspects of traffic and examine arbitrary or unilateral decisons that are made by politicians and traffic authorities that really are damaging to the traffic flow," he said.

Rosenson, a former Army captain, began piloting helicopters for WWDC's traffic reporters in the early 1960s. He began broadcasting when WWDC traffic reporter Marie MacDonald and a pilot were killed in a crash in 1966. In 1980, he joined WMAL, where he began using a plane instead of a helicopter after the station's management decided it was more efficient and economical.

Both Marbourg and Starling said their decision to join the profession was influenced by Rosenson.

"I listened to Dan on the air when I was 14 and 15," said Starling, 31.

Starling, who majored in radio and television at the University of Maryland, said he "wasn't sure whether I wanted to be a disc jockey, a reporter or what. And the more I thought about it, the more I wanted to be a traffic reporter. It seemed that Dan was having a good time."

Starling grew up in Hyattsville and attended Northwestern High School. He flies out of College Park Airport, minutes away from his home.

One of the best known broadcasters on WASH, Starling said he likes the freedom the job affords: "There's nobody looking over my shoulder. I decide where to fly. I own my own plane, and I take care of it. It gives me a feeling of independence."

Marbourg, in turn, listened to the broadcasts of both Rosenson and Starling before joining them aloft. He began filling in for Starling during vacations and landed the job at WTOP.

"The ability to perceive what is happening and then to turn around and explain it in a useful manner is a challenge to the senses," he said.

Marbourg, 38, is the only one of the reporters who does not fly himself. He is also the only one with an on-the-ground partner, WTOP reporter Dave Statter.

Statter, with his car full of radios, can conduct interviews with the people involved in accidents and can identify landmarks that are not discernible from the air. On the other hand, Rosenson and Starling fly alone, playing the roles of pilot and broadcaster simultaneously.

"You have to work at this job in order to conduct it safely," said Marbourg who never forgets that his predecessor at WTOP, Steve Thompson, crashed in 1980, spent two months in intensive care and now walks with a cane. "I've spent a lot of time looking for the longest hole on golf courses" to use for emergency landings.

Starling also knows the value of golf courses: he has twice been forced to land on them in emergencies: at Silver Spring in 1976 when his plane's engine failed and at Tyson's Corner in 1978.

"Statistically, it's supposed to be a dangerous occupation," he said. "I have had some difficulty getting life insurance."

The three reporters are in constant radio contact with each other while in the air.

"We started talking to each other because we found we would all fly around the same accident," which posed a safety hazard, Starling said. They share stories and traffic information, discuss the morning's newspaper and keep each other company as they watch streams of cars pour in and out of the city.

"There are very few people who understand what we're doing up there," Marbourg said. "And how unpleasant it can be after five windy days when you're literally physically sick doing what you're doing.

"We're the only people who can commiserate with each other about how much we'd rather be on the ground, except we can't afford the pay cut," said Marbourg, who earns $28,000, well below what the other two earn.

Starling's plane whizzed by in front of Rosenson's, on its way home at the end of rush hour.

"Talk to ya later, Wally," said the Captain as he signed off.