Tonga's domestic airline Real Tonga is still waiting for government to finalise certification of its MA-60 aircraft, the airline's manager says.
The plane, gifted from China, has been sitting on the tarmac after a controversial stand-off between Tonga and New Zealand, who warned it was not certified properly and cautioned New Zealand tourists from flying on it.
Last year the Tongan government agreed to adopt New Zealand's civil aviation standards and ensure the plane was certified accordingly.
The Pacific Aviation Safety Office was asked to consult and has been co-ordinating with the Tongan Government, who also called in the Chinese donors to assist.
The plane underwent test flights some weeks ago and Real Tonga's Tevita Palu said he would like to have more assistance from the Tongan government to get it up in the air.
He said his company had been licenced to fly the plane and has felt the financial impact of having it sitting idle.
Mr Palu said there had always been a commercial risk in using the plane as its ongoing maintenance would depend on support from China and its engineers.