Rangemaster (Navion)
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Private
Flight Crew Last 90 Days 25; Flight Crew Total 500; Flight Crew Type 100
Communication Breakdown; Time Pressure; Troubleshooting; Workload
Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Took Evasive Action; General Maintenance Action
Aircraft
Climbing out; smoke was noticed in the cockpit. I had already established two-way communication with a Class C airport for transit clearance and was transmitting a discreet transponder code (with Mode C.) I alerted ATC of the situation and advised that I was turning off all electrical items -- hence NORDO and NO Transponder. Smoke was evacuated by slightly opening door. I did not declare an emergency. No priority was requested or accepted. I ultimately landed without incident at intended destination after briefly turning electrical back on and advising ATC of intentions. I was instructed to call ATC via telephone after landing and I complied. Due to the situation; I was in a Class 'C' Airspace without two-way communication or Mode-C though I did make ATC aware of the situation and my intentions. Problem preliminarily diagnosed as a heater diverter box which chaffed and made contact with a battery cable; heating the heater control cable melting its plastic shroud. Nothing caused a proximity conflict with any other aircraft; no other traffic was diverted to my knowledge.
A Navion Rangemaster pilot reported smoke in the cockpit so he secured all electrical and proceeded NORDO to his Class C destination where a shorted battery cable wire near the heater-diverter box was found.