Jakarta. The small plane that crashed in Serpong, killing all three people onboard on Sunday, wasn’t equipped with the cabin voice recording device known as a black box, the National Transportation Safety Committee (KNKT) revealed on Monday.

KNKT Head Soerjanto Tjahjono said his team relies on air traffic controllers at Halim Perdanakusuma Airport and Soekarno-Hatta Airport to obtain the last recorded conversations with the pilot of the Tecnam P2006T plane.

"The plane didn’t have a black box. We learned that they made the last contact with the Halim ATC but haven’t received the recording of the last communication," Soerjanto. "They also established communication with the ATC at Soekarno-Hatta Airport."

The plane, operated by Indonesia Flying Club, took off from Pondok Cabe Airport in South Tangerang for a round trip to Salakanagara Airport in the Tanjung Lesung industrial area, Pandeglang Regency, to trial a new airstrip, he said.

On its way back to Pondok Cabe, the plane crashed near an open field at Bumi Serpong Damai real estate.

The committee still cannot determine the exact cause of the disaster, which killed the pilot, co-pilot, and a mechanic during the rainy Sunday afternoon, as the investigation is still in its early stages.

"We’re still examining documents retrieved from the plane to assess its airworthiness and the pilot licenses," Soerjanto said.

Even if the flight was recreational, the pilot was required to have at least a private pilot license, he added.