Although they haven’t been manufactured for a decade and a half, Twin Commanders continue as workhorses for many small- to medium-size companies, thanks to Twin Commander Aircraft Corp. (TCAC).

The Arlington, Wash. company has increased the periodic inspection interval for many turboprop Twin Commanders, received FAA approval for the Meggitt Avionics Magic 2100 digital flight control system, and the Magic electronic flight and engine instrumentation system, and continues to convert old Twin Commanders into Grand Renaissance Twin Commanders.

TCAC (Booth No. 1863) supports the existing fleet through 17 service centers in 14 states, as well as six authorized facilities in five countries. Capabilities differ among the centers, which include the Grand Renaissance completion center, Meggitt Magic sales and installation center, aircraft sales and a Honeywell engine service center.

According to TCAC, customers find its service centers to be a complete resource for technical support and advice concerning their Twin Commanders. The focal point of the service centers’ relationship with TCAC is the Twin Commander Advisory Committee, which includes representatives from the centers and TCAC. It meets at least quarterly.

To date, about 150 Honeywell TPE331-10T engines have been installed on turboprop Twin Commanders, replacing standard TPE331-5 engines. The Dash 5 engines have a thermodynamic limit of about 800 shp, while the Dash 10T engines have an upgraded turbine section that yields a 1,000-shp thermodynamic limit. The company said this results in much-improved time-to-climb and 300-kt-plus cruise performance.

TCAC said that as of this year’s NBAA convention, factory authorized Twin Commander service centers have completed 35 Grand Renaissance Twin Commanders. Each airplane begins as a standard Twin Commander and then is disassembled down to the bare airframe, inspected and rebuilt according to factory specifications and procedures.

Every major system and component on the airplane is either replaced or overhauled, and each airplane is given factory-overhauled Dash 10T engines, a new custom interior and custom paint. This year, the Meggitt Magic electronic panel and autopilot have been added to the Grand Renaissance specs.

Meanwhile, the periodic inspection interval for many turboprop Twin Commanders is being extended 50 percent to 150 hr. TCAC said the change from the existing 100-hr inspection requirement resulted from an extensive review of inspection procedures and maintenance history of the fleet.

In addition, maintenance limits schedules for the Honeywell engines, Hartzell and Dowty propellers and other components used on Twin Commanders have been revised to coincide with the new 150-hr inspection interval. Service centers have the flexibility to continue using OEM maintenance schedules for those components.

Twin Commander Aircraft was founded in 1989 to acquire the type certificates, tooling, remaining parts inventory and rights to all multi-engine piston and turbine-powered Commander models from Gulfstream Aerospace. TCAC is a division of Precision Aerospace Corp.