DETROIT (AP) _ The pilot of a DC-9 said dense fog and poor runway markings caused him to take two wrong turns into the path of another jet taking off at Detroit Metropolitan Airport.

A National Transportation Safety Board hearing resumed this morning into the Dec. 3 runway collision of two Northwest Airlines jetliners that killed eight people.

A Northwest safety official today criticized the airport's design and what he said were unclear control tower instructions to DC-9 pilot William Lovelace and co-pilot James Schifferns, who testified Tuesday.

''Considering the totality of what the crew had to deal with, I would say that directions were challenging,'' said Robert Boston, manager of flight standards for the Eagan, Minn.-based airline.

Lovelace testified blamed the first wrong turn on a ground marking.

''I was looking to pick up a yellow taxi line, and that put me right into the throat'' of the wrong runway, the Northwest Airlines pilot said. ''I was following a misleading sign that was without a destination arrow.''

Schifferns, broke into tears as he described chaos and terror on the burning aircraft.

''You can train all you want, but it's a whole new game when your airplane explodes on you,'' Schifferns testified. ''There's destruction, the debris, the screaming. ... It becomes every man for himself. Your instinct takes over.''

Schifferns broke down describing the crew's efforts to save flight attendant Heidi Joost, 43, who died trying to open a rear escape hatch.

Lovelace said thick fog led to the second wrong turn onto a runway where a Northwest Boeing 727 was taking off.

''I looked out the window and here comes the Boeing,'' Lovelace said.

The 727's wing struck the DC-9's body. Fuel from the wing touched off a fire that killed eight of 44 people on the Pittsburgh-bound DC-9. All 153 aboard the Memphis, Tenn.-bound 727 escaped serious injury.

Schifferns and other pilots also testified Tuesday that the airport lacks many safety features found at comparable airports worldwide.

''Detroit is not the easiest airport to get around under the best of conditions,'' said Robert Ouelette, captain of the 727.