Flight of Enstrom 280FX with Allison turboshaft

Description

The exact day is unknown and will be updated.
The installment and testing of an Allison turbine powerplant on the 280FX Shark led to the beginning of the Model 480 project.

Source:   "Enstrom 480/TH-28".  Rotorcraft Forecast (2014).  Forecast International, 2014.  Section B, page 4.