A few years ago I was an FO in a large elderly T - Prop airliner. The cockpit had very poor air circulation so the company had added auxiliary fans behind each pilot seat to held move the air around. One day we were flying along when both the Captain and I simultaneously smelt the odour of burning electrical components .
We looked around and noticed that a stream of smoke was streaming out of the top of the fan behind me. I immediately unstrapped to access the cockpit fire extinguisher and the power switch to the unit, both inaccessible if I was strapped in (great design
)
While doing this the smoke stream impacted my upper head. I immediately felt a strong burning sensation in both eyes and blurred vision. Total exposure was only 1 or 2 seconds. When we got to the destination I went to the hospital emergency ward and was diagnosed with contact conjunctivitis in both eyes. My eyes were flushed and I was grounded for 3 days.
My Take Away:
I was amazed at how little electrical smoke was required to seriously impact my ability to perform piloting duties. In this case having a second pilot meant I did not have to do very much to get us safely on the ground. The cockpit was also a lot bigger than a light aircraft. This has changed the way I think of potential small aircraft electrical fires.
My Recommendation:
At the first sign of electrical fire
turn off the Master switch. Don't try to troubleshoot, don't try to get a radio call out, pull the checklist etc etc , turn off all power immediately.