C182 pilot has electrical problem en route class C airspace.

Attributes
ACN	564869
Time
Date	200211
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : c90.tracon
State Reference	IL
Altitude	msl single value : 2300
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : c90.tracon
Operator	general aviation : personal
Make Model Name	Skylane 182/RG Turbo Skylane/RG
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	None
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 20 flight time total : 1250 flight time type : 800
ASRS Report	564869
Person 2
Affiliation	government : faa
Function	controller : approach
Events
Anomaly	aircraft equipment problem : less severe airspace violation : entry non adherence : far
Independent Detector	aircraft equipment other aircraft equipment : alternator warning light volt meter other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

While returning to my home airport, mwc, from a business trip to lexington, ky, my alternator began to cause problems. As I approached waukegan, il, from the south with flight following services from ord approach my alternator light came on and my ammeter showed that my battery was discharging. The engine monitor showed that my battery voltage dropped from normal (13.5 volts) to about 11.5 volts. I told ord that I was going to land at ugn. I turned off all unnecessary electrical equipment, contacted ugn tower and set up for landing at ugn. Approximately 2 mi from ugn my alternator went back into service and all system returned to normal. As a result, I changed course back to mwc. A few mins later, in the vicinity of enw, the same thing happened. When system returned to normal, I again turned toward mwc. A few mins later, while getting RA's from mke approach, the alternator failed again. I had been told to stay clear of the class C airspace at mke. At the time, I was at 2300 ft MSL and about 10 mi southeast of mke. I was very interested in getting home quick, before my battery failed. The situation was tense, and I was distracted by the mechanical problem. I probably violated the class C airspace before I descended to 2000 ft. I made it home without a problem. In retrospect, I should have landed at enw.

Original NASA ASRS Text

Title: C182 PLT HAS ELECTRICAL PROB ENRTE CLASS C AIRSPACE.

Narrative: WHILE RETURNING TO MY HOME ARPT, MWC, FROM A BUSINESS TRIP TO LEXINGTON, KY, MY ALTERNATOR BEGAN TO CAUSE PROBS. AS I APCHED WAUKEGAN, IL, FROM THE S WITH FLT FOLLOWING SVCS FROM ORD APCH MY ALTERNATOR LIGHT CAME ON AND MY AMMETER SHOWED THAT MY BATTERY WAS DISCHARGING. THE ENG MONITOR SHOWED THAT MY BATTERY VOLTAGE DROPPED FROM NORMAL (13.5 VOLTS) TO ABOUT 11.5 VOLTS. I TOLD ORD THAT I WAS GOING TO LAND AT UGN. I TURNED OFF ALL UNNECESSARY ELECTRICAL EQUIP, CONTACTED UGN TWR AND SET UP FOR LNDG AT UGN. APPROX 2 MI FROM UGN MY ALTERNATOR WENT BACK INTO SVC AND ALL SYS RETURNED TO NORMAL. AS A RESULT, I CHANGED COURSE BACK TO MWC. A FEW MINS LATER, IN THE VICINITY OF ENW, THE SAME THING HAPPENED. WHEN SYS RETURNED TO NORMAL, I AGAIN TURNED TOWARD MWC. A FEW MINS LATER, WHILE GETTING RA'S FROM MKE APCH, THE ALTERNATOR FAILED AGAIN. I HAD BEEN TOLD TO STAY CLR OF THE CLASS C AIRSPACE AT MKE. AT THE TIME, I WAS AT 2300 FT MSL AND ABOUT 10 MI SE OF MKE. I WAS VERY INTERESTED IN GETTING HOME QUICK, BEFORE MY BATTERY FAILED. THE SIT WAS TENSE, AND I WAS DISTRACTED BY THE MECHANICAL PROB. I PROBABLY VIOLATED THE CLASS C AIRSPACE BEFORE I DSNDED TO 2000 FT. I MADE IT HOME WITHOUT A PROB. IN RETROSPECT, I SHOULD HAVE LANDED AT ENW.

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.