Penobscot Island Air demands $388k in unpaid US post fees ch-aviation 16:47 Thu, 23 Apr Article paywall
Penobscot Island Air to resume mail flights to Knox County islands; USPS to pay 25% balance WABI TV 5 13:10 Wed, 22 Apr
Penobscot Island Air halts USPS mail flights to Knox County islands over $388K payment dispute WABI TV 5 23:46 Tue, 21 Apr
