Smoke in cockpit of C172 causes precautionary landing at btv.

Attributes
ACN	550392
Time
Date	200206
Day	Wed
Local Time Of Day	1201 To 1800
Place
State Reference	VT
Altitude	msl single value : 3300
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : btv.tracon
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : cfi
Experience	flight time last 90 days : 45 flight time total : 425 flight time type : 250
ASRS Report	550392
Person 2
Affiliation	government : faa
Function	controller : approach
Events
Anomaly	aircraft equipment problem : less severe other anomaly
Independent Detector	other flight crewa
Resolutory Action	controller : provided flight assist flight crew : landed as precaution flight crew : landed in emergency condition
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Smoke coming from landing light switch in 1979 cessna 172. Declared a 'pan-pan' and turned out of clouds to VMC and advised ATC of problem. Landed safely. Upon maintenance inspecting, nothing was found. Aircraft was returned to service.

Original NASA ASRS Text

Title: SMOKE IN COCKPIT OF C172 CAUSES PRECAUTIONARY LNDG AT BTV.

Narrative: SMOKE COMING FROM LNDG LIGHT SWITCH IN 1979 CESSNA 172. DECLARED A 'PAN-PAN' AND TURNED OUT OF CLOUDS TO VMC AND ADVISED ATC OF PROB. LANDED SAFELY. UPON MAINT INSPECTING, NOTHING WAS FOUND. ACFT WAS RETURNED TO SVC.

Data retrieved from NASA's ASRS site as of July 2007 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.