M20P pilot had generator failure. This resulted in a no communication approach in VMC at spx.

Attributes
ACN	512908
Time
Date	200105
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bpt.airport
State Reference	TX
Altitude	msl single value : 8500
Environment
Flight Conditions	Mixed
Weather Elements	other
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zhu.artcc tracon : lch.tracon
Operator	general aviation : personal
Make Model Name	M-20 F Executive 21
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	VFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : private
ASRS Report	512908
Person 2
Affiliation	government : faa
Function	controller : radar
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	faa : reviewed incident with flight crew other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Aircraft experienced a failure of the generator/charging system that caused gradual discharge of battery. While in cruise, at 8500 ft MSL, over bpt's TRSA, I experienced loud feedback in the system and was unable to receive/transmit. I was unable to notify ZHU -- lake charles especially, with when I was VFR flight following. I placed the transponder to 1200 and continued my flight into prevailing VFR. I descended into destination at spx and made a NORDO entry and landing to the traffic pattern. On arrival, the FBO attendant informed me that center wanted to talk to me. I was on the ground approximately XA00 and made contact with ZHU at approximately XA20. Factors include: 1) an ammeter that is small, and indicates +/- charging indication, without negative/discharge indication. 2) my failure to detect and notify center of possible radio/transponder difficulties due to discharging battery while flight following. 3) I had a handheld communication with me that had inadvertently been left on the day before, discharging totally and becoming useless. Note: if my transponder was not transmitting due to low power, I may have been seen as a 'primary target only' within houston class B mode C veil on my approach into spx.

Original NASA ASRS Text

Title: M20P PLT HAD GENERATOR FAILURE. THIS RESULTED IN A NO COM APCH IN VMC AT SPX.

Narrative: ACFT EXPERIENCED A FAILURE OF THE GENERATOR/CHARGING SYS THAT CAUSED GRADUAL DISCHARGE OF BATTERY. WHILE IN CRUISE, AT 8500 FT MSL, OVER BPT'S TRSA, I EXPERIENCED LOUD FEEDBACK IN THE SYS AND WAS UNABLE TO RECEIVE/XMIT. I WAS UNABLE TO NOTIFY ZHU -- LAKE CHARLES ESPECIALLY, WITH WHEN I WAS VFR FLT FOLLOWING. I PLACED THE XPONDER TO 1200 AND CONTINUED MY FLT INTO PREVAILING VFR. I DSNDED INTO DEST AT SPX AND MADE A NORDO ENTRY AND LNDG TO THE TFC PATTERN. ON ARR, THE FBO ATTENDANT INFORMED ME THAT CTR WANTED TO TALK TO ME. I WAS ON THE GND APPROX XA00 AND MADE CONTACT WITH ZHU AT APPROX XA20. FACTORS INCLUDE: 1) AN AMMETER THAT IS SMALL, AND INDICATES +/- CHARGING INDICATION, WITHOUT NEGATIVE/DISCHARGE INDICATION. 2) MY FAILURE TO DETECT AND NOTIFY CTR OF POSSIBLE RADIO/XPONDER DIFFICULTIES DUE TO DISCHARGING BATTERY WHILE FLT FOLLOWING. 3) I HAD A HANDHELD COM WITH ME THAT HAD INADVERTENTLY BEEN LEFT ON THE DAY BEFORE, DISCHARGING TOTALLY AND BECOMING USELESS. NOTE: IF MY XPONDER WAS NOT XMITTING DUE TO LOW PWR, I MAY HAVE BEEN SEEN AS A 'PRIMARY TARGET ONLY' WITHIN HOUSTON CLASS B MODE C VEIL ON MY APCH INTO SPX.

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.