What happened
A few minutes after departure, the pilot performed a precautionary off-airport landing in a cleared area within a marsh section adjacent to the bay. This maneuver was executed to address a sticking floor push-to-talk microphone switch.
After landing, the helicopter was shut down, allowing the pilot to successfully correct the issue with the microphone switch. Upon restarting the engine and attempting to take off into a hover, the aircraft spun to the right. The pilot managed to land the helicopter back in the marsh area.
Following the second landing, the pilot shut down the engine. However, heat from the engine exhaust system ignited the surrounding grass. The resulting fire spread rapidly, consuming the helicopter and a section of the marsh area before the fire department arrived to extinguish the flames.
Findings
The fire was caused by the heat from the engine exhaust system igniting the vegetation in the marsh area.