The pilot of a PA28A reports that he may have landed without a clearance, but he is not sure.

Attributes
ACN	431130
Time
Date	199903
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : grr.airport
State Reference	MI
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	tower : mdw
Operator	general aviation : personal
Make Model Name	PA-28 Cherokee/Archer II/Dakota/Pillan/Warrior
Operating Under FAR Part	Part 91
Flight Phase	landing other
Flight Plan	None
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 9 flight time total : 150 flight time type : 16
ASRS Report	431130
Person 2
Function	controller : radar flight crew : captain
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : less severe non adherence other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

I was on tower frequency and on final at dusk when I noticed that the alternator annunciator light was on. After checking the ammeter, I confirmed that the alternator was not functioning correctly. I continued my approach and had an otherwise uneventful landing. After landing, the tower cleared me to taxi back to parking on his frequency. I do not recall if the tower cleared me to land. It probably did, and if that was the case, this report is not necessary.

Original NASA ASRS Text

Title: THE PLT OF A PA28A RPTS THAT HE MAY HAVE LANDED WITHOUT A CLRNC, BUT HE IS NOT SURE.

Narrative: I WAS ON TWR FREQ AND ON FINAL AT DUSK WHEN I NOTICED THAT THE ALTERNATOR ANNUNCIATOR LIGHT WAS ON. AFTER CHKING THE AMMETER, I CONFIRMED THAT THE ALTERNATOR WAS NOT FUNCTIONING CORRECTLY. I CONTINUED MY APCH AND HAD AN OTHERWISE UNEVENTFUL LNDG. AFTER LNDG, THE TWR CLRED ME TO TAXI BACK TO PARKING ON HIS FREQ. I DO NOT RECALL IF THE TWR CLRED ME TO LAND. IT PROBABLY DID, AND IF THAT WAS THE CASE, THIS RPT IS NOT NECESSARY.

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.