From what I have read, ANG operated the Q400 into Kieta from the end of 2014 when the airport was recovered and rebuilt.
In 2019, the Q400 was due to be replaced by the F100. I assumed that happened, but there is a Notam current now stopping F100 ops
due to pavement issues.
There are no Kieta flights in the ANG Timetables.
Sounds like the airport may need more maintenance.
PS. The COVID issue may have also caused a shut down in flights.
From the ANG Website 5 months ago:
Updated Domestic Air Travel RequirementsApril 27, 2020
Flights to Buka and Kieta airports in the Autonomous Region of Bougainville (ARoB) still require approval from the Bougainville SoE Controller.
Air Niugini is operating occasional flights to Buka, based on Bougainville SoE Controller approval,
but generally at present there is not any approval for uplift of passengers into Buka or Kieta.