As investigators began picking up clues to the cause of the second fatal commuter plane crash in six weeks, Transportation Secretary Federico F. Pena on Wednesday ordered a safety audit of the nation's airlines and an accelerated timetable for new, stricter safety rules for commuter airlines.

The rules, which would essentially force commuter airlines to meet the same standards as major carriers, were first recommended by the National Transportation Safety Board after an American Eagle ATR-72 crashed in Indiana on Oct. 31, killing 68 people.The crash of an American Eagle Jetstream Super 31 on Tuesday night, killing 15 of the 20 people aboard, increased the pressure for changes.

Pena also said Wednesday that he would soon meet with airline chief executives and safety directors, as well as pilots and manufacturers, to discuss safety issues in an industry recently plagued by crashes.

A clearer picture of what happened before the crash on Tuesday began to emerge Wednesday night. National Transportation Safety Board officials said at a news briefing that preliminary information from the flight-data and the cockpit-voice recorders showed that there had apparently been an engine flameout as the turboprop plane descended for a landing.

A flameout occurs when combustion stops in a jet or turboprop engine, but a federal official, who spoke on condition of anonymity, said this model plane should be able to fly on one engine after a flameout.

The cockpit crew also talked about a missed approach on the voice recorder, said James Hall, chairman of the safety board. Fifteen seconds before the crash, the plane accelerated sharply and veered off its heading toward the runway. Then, an intermittant warning, which investigators have not identified, sounded.

Officials stressed that this information was preliminary and that they had not ruled out any factors, including the weather, as a possible cause of the crash. The crash occurred at 7 p.m. in rain and fog.

American Eagle, the commuter affiliate of American Airlines, is one of the many short-haul carriers that would be affected by the new safety standards. A preliminary version of the rules was endorsed by the Federal Aviation Administration last week.

The proposals - including more pilot training, fewer pilot flying hours and a requirement that young pilots be paired with more experienced ones - will be completed within 100 days, Pena said, but no deadline was set for them to take effect.

Critics of the commuter airlines' safety record, as well as officials of the Regional Airline Association, which represents the carriers, said a quick change in the regulations was unlikely.

Pena flew to the crash site Wednesday morning with David Hinson, the federal aviation administrator, to look over the wreckage of American Eagle Flight 3379, which crashed on Tuesday evening, killing 15 people and injuring five.

Inspectors with the National Transportation Safety Board began picking through the debris, looking for clues as to what caused the turboprop Jetstream Super 31 to go down in rain and fog in a wooded area southwest of Raleigh-Durham International Airport.