I've had two cases on my Fly Baby where I've left the master out and smoked the battery. I've been contemplating adding an "occupancy sensor" to note when the master is on, but the aircraft is unoccupied.

I'm looking for ideas on how to sense when there's nobody in the seat without using a sensor on the seat mount or the seat itself.

I may try to hook a magnetic switch that senses when the stick is aft of the full-down position (gravity moves the elevators down when no one's holding the stick). Might be able to rig a switch to the floorboards, or a light/reflector system that has a beam broken when the legs go into the under-panel area.

Any ideas?

The "Alert" portion of the system is still under contemplation. I changed my shut-down checklist to ensure power's off, but find my close calls recently have been when I've turned the switch on to work on the airplane. So I'm not going to add an obnoxious hooter; more like something that chirps every fifteen seconds. Maybe just a damn bright LED.

Ron Wanttaja