Pilot of C172 advises the fluorescent instrument panel lighting rheostat was malfunctioning.

Attributes
ACN	663286
Time
Date	200506
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : tcy.airport
State Reference	CA
Altitude	msl single value : 4500
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : nct.tracon
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	None
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : multi engine pilot : instrument pilot : cfi
Experience	flight time last 90 days : 194 flight time total : 910 flight time type : 895
ASRS Report	633286
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Glareshield lt light is similar to a fluorescent light bulb which covers the entire instrument panel. Found in the newer C172's and C182's. In my incident it was a 2000 C172S. Problem: night flight. The rheostat knob which controled the function of the light was not working properly. Light would not stay in the off position. Light would turn off for about 5 percent of the time; flicker at best. It essentially destroyed my night vision making a very uncomfortable flight. An airworthiness directive should be put out for permanent deactivation and/or removal of the light and prevention of such light installation in current and future production. Light is not needed during day operations; and should never be used during night operations due to the effects on the pilot's night vision. I also feel that a non instrument rated pilot would not have made a safe flight given the conditions that were given to me during the flight.

Original NASA ASRS Text

Title: PLT OF C172 ADVISES THE FLUORESCENT INST PANEL LIGHTING RHEOSTAT WAS MALFUNCTIONING.

Narrative: GLARESHIELD LT LIGHT IS SIMILAR TO A FLUORESCENT LIGHT BULB WHICH COVERS THE ENTIRE INST PANEL. FOUND IN THE NEWER C172'S AND C182'S. IN MY INCIDENT IT WAS A 2000 C172S. PROB: NIGHT FLT. THE RHEOSTAT KNOB WHICH CTLED THE FUNCTION OF THE LIGHT WAS NOT WORKING PROPERLY. LIGHT WOULD NOT STAY IN THE OFF POS. LIGHT WOULD TURN OFF FOR ABOUT 5 PERCENT OF THE TIME; FLICKER AT BEST. IT ESSENTIALLY DESTROYED MY NIGHT VISION MAKING A VERY UNCOMFORTABLE FLT. AN AIRWORTHINESS DIRECTIVE SHOULD BE PUT OUT FOR PERMANENT DEACTIVATION AND/OR REMOVAL OF THE LIGHT AND PREVENTION OF SUCH LIGHT INSTALLATION IN CURRENT AND FUTURE PRODUCTION. LIGHT IS NOT NEEDED DURING DAY OPS; AND SHOULD NEVER BE USED DURING NIGHT OPS DUE TO THE EFFECTS ON THE PLT'S NIGHT VISION. I ALSO FEEL THAT A NON INST RATED PLT WOULD NOT HAVE MADE A SAFE FLT GIVEN THE CONDITIONS THAT WERE GIVEN TO ME DURING THE FLT.

Data retrieved from NASA's ASRS site as of January 2009 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.