Troppo
I know jack about Foreign exchange, but I'm guessing it is as simple as the country is not getting the money in that it thought it would get. The only thing it has to sell is its natural resources, and the prices of that has tanked.
Consider that it has recently paid for the Sth Pac games, the FIFA Womens U20 World Cup Soccer tournament, is presently budgeting for APEC in 2018, not to mention all the highways it has built, it is no wonder there is no Fourex.
Taxes are going up, but governments don't get much tack from someone who is on 3PGK an hour, so the if you are working there expect either direct or indirect taxes to affect you, and probably hard.
All simple I think, PNG is spending more than it is earning, it has to buy it overseas, it probably borrowed more than it should.....and with the price of natural resources being so low they have not enough foreign money left over to be able to pay salaries overseas.
Scary to think that Aviation revolves around the USD.
Just as an afterthought (and the reason for the edit)...so you have to be paid into a PNG bank account in PGK, so if you live OS, you have to pay the transfer fees, exchange rates, bank fees, so the salary with the airline this thread is about , drops even lower.