Officials in Alaska are searching the land and sea Friday for a small airplane that went missing, while the nation awaits news of the 10 people on board and wonders what caused the plane to drop off the radar.

The plane was over the Norton Sound, off the coast of its destination in Nome, Alaska, when it stopped sending its location signal on Thursday afternoon, according to the Alaska Department of Public Safety and the U.S. Coast Guard. Just before it vanished, the plane’s data showed it experienced a rapid loss of altitude and speed, officials said Friday.

Since then, search crews have been looking for a sign of the turboprop Cessna Caravan operated by Bering Air.

Though aerial incidents involving fatalities are rare, smaller accidents happen frequently throughout the country, and sometimes aircraft stop sending signals about where they are, said aviation attorney and former Air Force navigator Jim Brauchle. In Alaska, many people get around on small planes, and the state has a disproportionately high number of accidents compared to the rest of the country, according to the National Institute of Occupational Safety and Health.

“When the communication is gone and they can’t identify where the aircraft is or talk to somebody on the radio, then that’s how they’ll classify the aircraft as missing,” Brauchle said.

That’s a less frequent problem today thanks to technology called Automatic Dependent Surveillance-Broadcast, or ADS-B, which is required on all aircraft and broadcasts location data to air traffic controllers. Still, “it happens,” Brauchle said.

Here’s what to know about how a plane can go missing:

How officials can lose a plane’s location

Airplanes fly with a transponder, which sends continuous data on its current altitude, airspeed, latitude and longitude to receivers on the ground. If the the transponder stops sending signals, it could be because of an electrical failure or a problem with the transmitter itself, Brauchle said.

Loss of location data wouldn’t necessarily indicate a disaster on its own, he said, but the fact that the plane never made it to its destination even after many hours is not a good sign.

If there was a catastrophic mechanical failure on the plane, a control issue or if the pilot became spatially disoriented due to visibility and weather conditions, the plane likely crashed over land or sea, he said.

Where did the Alaska plane disappear?

Officials said the plane’s last known position was over the water. It’s likely that the plane went down near where the transponder stopped sharing location data, Brauchle said, but if there was a loss of power to the plane, it may have glided farther away as it descended. Authorities will probably look at the last altitude readout to estimate how far it could have drifted from the last position, he said.

Snow and freezing fog were reported in the plane’s flight path on Thursday, with visibility between 1 and 7 miles where it departed and half a mile to 8 miles where it was supposed to land, according to AccuWeather Senior Meteorologist Tom Kines.

“Weather conditions likely varied greatly along the scheduled flight path over Norton Sound. Water temperatures have been near freezing in Norton Sound. Hypothermia and cold-water shock are a major concern for first responders and officials working on search and rescue operations near or on the water,” Kines said in a statement.

Missing plane:What we know about the Bering Air flight, search

Several state and federal agencies are searching by air and land, scouring sea ice and coastline, according to the Nome Volunteer Fire Department in an update Friday. The public may not know exactly what happened for quite some time as aviation authorities conduct a full investigation, Brauchle said.

It’s not likely anyone on the plane survived, another tragedy in a string of aviation disasters since the year began, Brauchle said. On Jan. 29, an American Airlines passenger plane and an Army helicopter collided near Washington, D.C., killing 67 people in the deadliest air disaster in more than two decades. Just days later, a Medevac jet crashed into a busy neighborhood in Philadelphia, killing seven people and injuring over 20 others. Brauchle said the recent high-profile accidents are putting the nation on high alert to plane incidents, but it’s coincidence that they happened back-to-back.

“My initial thought is with the families,” Brauchle said. He’s represented family members who have lost loved ones in aviation accidents. “People aren’t supposed to die in plane crashes.”

Contributing: Eve Chen, Thao Nguyen and Christopher Cann, USA TODAY; Reuters