MAKASSAR, Indonesia (AP) – A jetliner with 102 people aboard that disappeared after encountering 80 mph winds over northern Indonesian waters twice changed course, an official said, as authorities widened the search Friday for the Boeing 737.

A U.S. National Transportation Safety Board team arrived to help investigate the apparent crash of Adam Air Flight KI-574, which disappeared from the radar Monday near the Sulawesi coastal town of Majene without issuing a mayday.

Three Americans – Scott Jackson, 54, and his daughters 18-year-old Lindsey and 21-year-old Stephanie, of Bend, Ore., – were on board.

“Whatever happened to the plane, it was likely rapid and catastrophic,” said Patrick Smith, a U.S.-based airline pilot and aviation commentator, pointing to a possible massive structural failure due to metal fatigue or an onboard explosion.

He noted that in many accidents, “there are no distress calls simply because the cockpit crew is too busy dealing with the situation rather than calling around for help.”

The plane left Indonesia’s main island of Java for Manado on Sulawesi but altered course and turned westward halfway into the two-hour trip after being warned of rough weather near the city of Makassar, said Eddy Suyanto, head of the search and rescue mission.

But when it ran into winds of more than 80 mph over the Makassar Strait, it changed course again, bringing the plane eastward toward land, then disappeared from the radar, he said.

It is not clear why there have been no transmissions from the plane’s emergency locator.

Smith speculated it may not have been operational or – in the event of a crash at sea – that it could have sank into an underwater trench from which its signals could not be picked up.

Nearly 3,000 soldiers, police and civilians have been trudging along steep jungle paths on Sulawesi, while sonar-equipped ships and a fleet of aircraft have scoured the sea over an area roughly the size of California.

With no sign of the wreckage, rescuers extended their search south toward the resort island of Bali, believing that in the event of a sea crash strong currents may have washed debris or bodies hundreds of miles away, officials said. Teams also patrolled coasts further northeast.

Authorities wrongly said Tuesday the wreckage had been found with a dozen survivors, causing further anguish to relatives camped out at airports and hotels in Manado and Makassar.

About 50 protesters gathered in the capital, Jakarta, dressed like bloodied air-crash victims, calling for the resignation of the transport minister over the erroneous reports, which have made family members doubt almost anything officials tell them about the probe.

“All we do is watch television,” said Fandi, who had four relatives on the plane and like many Indonesians only uses a single name. “Officials from Adam Air aren’t able to tell us anything.”

Adam Air is one of about 30 budget carriers that sprang up in Indonesia after 1998, when the industry was deregulated. The rapid expansion has led to cheap flights to scores of destinations across Indonesia, but has also raised concerns about maintenance of the leased planes.

Air navigation can be difficult in Indonesia, which spans 6 percent of the equator, because there are gaps in the communications systems. Last year, an Adam Air Boeing 737 flew off course on a stretch of the same route and was lost for several hours before it made an emergency landing at a small airstrip, hundreds of miles off course.