Small aircraft pilot has difficulty with approach due to poor NDB indication.

Attributes
ACN	331257
Time
Date	199603
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : 29j
State Reference	SC
Altitude	msl bound lower : 1400 msl bound upper : 2300
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : clt
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	descent : approach landing : missed approach
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : commercial
Experience	flight time last 90 days : 15 flight time total : 1200 flight time type : 950
ASRS Report	331257
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : less severe other spatial deviation
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	flight crew : became reoriented other other
Consequence	Other
Supplementary
Primary Problem	Navigational Facility
Air Traffic Incident	other

Narrative:

I was being vectored by charlotte approach for the localizer runway 2 approach to 29J. I received my final turn and clearance to intercept the localizer and shoot the approach, maintaining 2300 ft until rally NDB. I intercepted the localizer and tracked it inbound, my ADF indicating rally NDB ahead. After scanning my flight instruments, I glanced back at the ADF which now indicated having passed rally NDB, my final approach fix. I now began my descent and timing for missed approach. After having descended from 2300 ft to about 1400-1500 ft, I was informed by charlotte approach that I had not reached rally NDB and that they were receiving a low altitude alert. I immediately began a climb and informed charlotte that I was going to climb back to 2300 ft. Charlotte approach asked if I would like vectors to shoot the approach again with them calling out rally NDB. I informed them that my ADF was giving false indications. They gave me vectors for the localizer approach and clearance and this time they called out rally NDB for me. The approach was successful. However, I did notice once again that the ADF would apparently lose its signal and give false indications. Callback conversation with reporter revealed the following information: reporter states that mechanics are trying to determine the problem. He has the aircraft in for its annual and when that is completed he will take it to the avionics shop and let us know if they find any problems with the ADF. Reporter called again after 3 weeks to say that there is some problem with the annual and he has not been able to have avionics check as yet.

Original NASA ASRS Text

Title: SMA PLT HAS DIFFICULTY WITH APCH DUE TO POOR NDB INDICATION.

Narrative: I WAS BEING VECTORED BY CHARLOTTE APCH FOR THE LOC RWY 2 APCH TO 29J. I RECEIVED MY FINAL TURN AND CLRNC TO INTERCEPT THE LOC AND SHOOT THE APCH, MAINTAINING 2300 FT UNTIL RALLY NDB. I INTERCEPTED THE LOC AND TRACKED IT INBOUND, MY ADF INDICATING RALLY NDB AHEAD. AFTER SCANNING MY FLT INSTS, I GLANCED BACK AT THE ADF WHICH NOW INDICATED HAVING PASSED RALLY NDB, MY FINAL APCH FIX. I NOW BEGAN MY DSCNT AND TIMING FOR MISSED APCH. AFTER HAVING DSNDED FROM 2300 FT TO ABOUT 1400-1500 FT, I WAS INFORMED BY CHARLOTTE APCH THAT I HAD NOT REACHED RALLY NDB AND THAT THEY WERE RECEIVING A LOW ALT ALERT. I IMMEDIATELY BEGAN A CLB AND INFORMED CHARLOTTE THAT I WAS GOING TO CLB BACK TO 2300 FT. CHARLOTTE APCH ASKED IF I WOULD LIKE VECTORS TO SHOOT THE APCH AGAIN WITH THEM CALLING OUT RALLY NDB. I INFORMED THEM THAT MY ADF WAS GIVING FALSE INDICATIONS. THEY GAVE ME VECTORS FOR THE LOC APCH AND CLRNC AND THIS TIME THEY CALLED OUT RALLY NDB FOR ME. THE APCH WAS SUCCESSFUL. HOWEVER, I DID NOTICE ONCE AGAIN THAT THE ADF WOULD APPARENTLY LOSE ITS SIGNAL AND GIVE FALSE INDICATIONS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES THAT MECHS ARE TRYING TO DETERMINE THE PROB. HE HAS THE ACFT IN FOR ITS ANNUAL AND WHEN THAT IS COMPLETED HE WILL TAKE IT TO THE AVIONICS SHOP AND LET US KNOW IF THEY FIND ANY PROBS WITH THE ADF. RPTR CALLED AGAIN AFTER 3 WKS TO SAY THAT THERE IS SOME PROB WITH THE ANNUAL AND HE HAS NOT BEEN ABLE TO HAVE AVIONICS CHK AS YET.

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.