King Air 360/360ER Unveiled By Textron Aviation Textron Aviation announced today the unveiling of their latest model, the King Air 360/360ER. As you would imagine, this is an upgraded version of the already very popular King Air 350/350ER. So what's different on the new King Air 360/360ER? The updated flagship turboprop offers the latest technological advancements in the cockpit, a redesigned cabin, and enhancements to passenger comfort. The aircraft is currently in production with customer deliveries expected to begin in the Fall of 2020.