This will not be the only aviation skeleton on the Tongan wardrobe, nor the first time creditors have been bitten. I think RTA would be at least number five since the days of SPIA (South Pacific Island Airways), long, long ago.
A monopoly it may be, but one needs to get Tonga in perspective. It is a small impoverished nation of approximately 100,000 - about the size of a small regional center in Australia. From memory there are five or seven domestic island airstrips, the shortest around 700 meters.
Principal foreign income used to be tourism, repatriated funds from 100,000 Tongans living overseas, and kava exports to Europe as an ingredient in the manufacture of "the pill".
It is a delightful and very beautiful island archipelago, with wonderfully friendly people. But it can't sustain airline ownership, especially to the extent expected by the aristocracy.
I feel very sorry for the plight of the average Tongan citizen. I can’t see them getting another air service in a hurry.
Been there, done that!