Beech 1900
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Landed As Precaution; Flight Crew Diverted; General Declared Emergency
Aircraft
[At cruise altitude] I started to notice a light odor of something the smelled like 'a greasy engine room;' but the First Officer could not smell it. As I continued to sniff around my EADI flickered out and went black. It was about then that the First Officer also noticed an odor. My side of the cockpit began to smell more like melting plastic. I decided the combination of melting plastic odor and failing electrical equipment could be the beginning of a potential fire in the cockpit and decided the safest action was to put the plane on the ground as quickly as possible. The nearest suitable airport that had [required] runway length and fire equipment was ZZZ. I declared an emergency with ATC; requested coordination with ground equipment; coordinated with company to have agents meet us there; and advised dispatch of what we were doing. We landed; and unloaded passengers into the terminal. I think this all worked out as well as it could despite the hassle to passengers. Pilots; ATC; Fire Department; and Station Agents all reacted quickly and professionally to a potentially catastrophic problem before it turned into one.
[Narrative 2 had no additional information]
B1900D flight crew reported noticing an electrical smell followed by failure of the Captain's EADI. An emergency was declared and the flight diverted to nearest suitable airport.