The flight data recorder and cockpit voice recorder of the Airlines PNG Bombardier Dash 8 Q100 that crashed on 13 October have been recovered.
The two devices have been sent to Australia for assessment, the airline said in a statement.
Its fleet of 11 Dash 8 aircraft remain grounded "until further notice", and all normal passenger services have been suspended until 22 October, it added.
"The airline is working with representatives of the airframe and engine manufacturers to gain approval for the aircraft to re-enter service," Airlines PNG said.
Its fleet of 10 de Havilland Canada Twin Otters remain in service.
Airlines PNG's chairman Simon Wild issued a statement, reiterating that the carrier adhered to safety standards.
He said that the airline has been audited for safety 16 times in the past year and met "every requirement", and all its Dash-8 pilots average more than 16,000 hours of flight time, including 15 years of experience flying in "the challenging PNG [Papua New Guinea] environment", said Wild.
The aircraft in the incident, which bears the registration P2-MCJ, was en route from Lae to the resort town of Madang when it crashed about 20 kilometres (km) (12.4 miles) south of its destination in the late afternoon, local time, on 13 October.
The airline later revealed that there had been "an emergency situation" on board and the pilots were attempting an emergency landing in bad weather when the crash happened. The aircraft split on impact and the fuselage caught fire, killing 28 people.
The Papua New Guinea authorities have sought the assistance of the Australian Transport Safety Bureau (ATSB), which has sent four investigators to the country. Transport Canada and Bombardier officials are also involved, as is engine manufacturer Pratt & Whitney, who supplied the aircraft's PW120 powerplants.
Source: Air Transport Intelligence news