C172 pilot reported heavy smoke in the cockpit; seeming to emanate from electrical equipment.

Attributes
ACN	1537372
Time
Date	201804
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	Electrical Power
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Flight Engineer Flight Crew Private Flight Crew Instrument
Experience	Flight Crew Last 90 Days 75 Flight Crew Total 242 Flight Crew Type 60
Events
Anomaly	Aircraft Equipment Problem Critical Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

Narrative:

On initial approach we detect heavy smoke from our electric equipment. I immediately open the window and switched off all electric devices and lights except the ignition and radios to talk to ATC. We landed on the first available airport which was ZZZ1. After touchdown we left the runway and turned everything off and left the aircraft. The firefighters came immediately but after shutting down everything the smoke stopped.

Original NASA ASRS Text

Title: C172 pilot reported heavy smoke in the cockpit; seeming to emanate from electrical equipment.

Narrative: On initial approach we detect heavy smoke from our electric equipment. I immediately open the window and switched off all electric devices and lights except the ignition and radios to talk to ATC. We landed on the first available airport which was ZZZ1. After touchdown we left the runway and turned everything off and left the aircraft. The firefighters came immediately but after shutting down everything the smoke stopped.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.