Part of landing gear, one 'black box' recovered from Indonesia jet

Divers have found a piece of landing gear from a crashed Lion Air jet, Indonesian authorities said Thursday, following the discovery of a critical black box that could explain why the brand-new plane plummeted into the sea, killing 189 people.

Search teams have been scouring the seabed for the fuselage of the Boeing-737 MAX 8, which plunged into the waters off Indonesia's northern coast shortly after takeoff on Monday despite only being in service a few months.

Referring to the landing gear, search and rescue agency head Muhammad Syaugi said late Thursday, "we have found part of it", as authorities piece together what caused the crash.

"Separately, we have found bigger parts of the plane than we have seen in previous days," he added, hours after officials announced the recovery of a data recorder from the plane.

There were no known survivors and only body parts have been found so far.

Relatives are desperate to be able to say goodbye to their loved ones and the first funeral for one of the passengers was held on Thursday. But many others have yet to be located and analysts hope more victims could still be found with the bulk of the wreckage.

"I assume that there will be a lot of bodies still strapped into the seats," aviation analyst Dudi Sudibyo told AFP.

Dozens of divers are taking part in the massive recovery effort along with helicopters and ships, but the authorities have all but ruled out finding any survivors.

The plane's black boxes, which airlines are required to install, offer investigators their best chance of discovering why such a new jet crashed. The devices record information about the speed, altitude and direction of the plane as well as flight crew conversations.

"The good news is we have found one of the black boxes," Syaugi told reporters earlier Thursday.

Authorities said a flight data recorder was recovered, but they were still looking for the cockpit voice recorder.

On a Jakarta dockside Thursday, Boeing and US National Transportation Safety Board officials joined the Indonesian team in sifting through twisted metal plane parts and piles of passengers' torn clothing, shoes, wallets and phones.

The single-aisle Boeing plane, which was on its way from Jakarta to Pangkal Pinang city, is one of the world's newest and most advanced commercial passenger jets.

Despite the name, black boxes are in fact bright orange with reflective stripes. They are built to survive at vast depths and in extreme heat, and are fitted with a beacon which can emit a signal for one month.

Black boxes help explain nearly 90 percent of all crashes, according to aviation experts.

"Data from the plane -- the engine, all the instruments -- are recorded there," Sudibyo said. "If there is an anomaly, some technical problem, it is recorded there too."