ROMULUS, MICH., DEC. 5 -- The copilot of a Northwest Airlines DC-9 that strayed onto the wrong runway, was struck by a Northwest 727 racing to take off and burst into flames at Detroit Metropolitan Airport has told federal investigators that he told the flight tower just before the collision he thought the DC-9 was on an active runway set aside for takeoffs, an official said tonight.

But the pilot, William Lovelace, said he never heard the comment from copilot James Schifferns, said John Lauber, a member of the National Transportation Safety Board. Lovelace said if he had heard such a remark, he "would've gone for the weeds" on the side of the runway, Lauber quoted him as saying.

Lovelace complained he was lost in the dense fog moments before the 727 struck his jetliner, according to individuals who have heard the recording of conversations between Lovelace and traffic controllers.

Lauber said investigators are trying to determine if runway and taxiway lights were on at the time of the crash and whether visibility on the ground was the required one-quarter mile, as air traffic controllers have said it was. "It's not inconceivable at all that visibility was less," Lauber said.

Lovelace, a 24-year veteran with Northwest, was making his first flight without another pilot observing since his return last week from a five-year leave, according to a Northwest spokesman. Lovelace took disability leave for kidney stone treatment in 1985. He opened a gift shop in Phoenix, where he lives, but it failed, according to his lawyer, and he was declared bankrupt in July. Friends said he is an accomplished magician and woodworker.

The Wayne County Medical Examiner's Office used dental records to identify the burned remains of those killed Monday.

The victims, all of whom were aboard the Pittsburgh-bound DC-9, were identified as Mary Blankenship, 37, of Windsor, Ontario; Mauro Bottigliome, 23, a Caracas, Venezuela, native temporarily working in Pittsburgh; Kingsley Brown, 30, of Pittsburgh; John Burke, 30, of Houston; Heidi Joost, 43, of Dearborn, Mich., a Northwest flight attendant; Thomas Kopriva, 50, Daniel Loughnane, 44, and Fred Zitto, 59, all of Memphis.

There was another fire this morning on the wing of a Northwest jetliner after it landed at Detroit Metropolitan Airport. The fire was put out and passengers safely left the aircraft, officials said.

Northwest Airlines spokeswoman Christy Clapp said residual fuel in an auxiliary power unit ignited on the right wing.