Air carrier track deviation while making NDB approach. Possible aircraft equipment problem.

Attributes
ACN	296599
Time
Date	199502
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : btr
State Reference	LA
Altitude	msl bound lower : 660 msl bound upper : 660
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	tower : btr
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 250 flight time total : 5400 flight time type : 1000
ASRS Report	296599
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	other spatial deviation
Independent Detector	other controllera
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While on the NDB 31 approach to btr, the controller asked if we were established on the approach, which we were indicating, and subsequently cleared us for the approach, we contacted tower and were advised that we appeared 1 mi south of the approach course, even though the bearing on my RMI was fluctuating plus or minus 3 degrees the mean showed us on course. I did take 10 degrees of correction to get on course that he would show on his bright scope. We got to minimums and tower asked us to report the airport in sight. I had the beacon but no runway. The tower controller advised us that he had us in sight and about that time the runway was found. I corrected to the right and made an uneventful landing, but my landing was made about 200 ft past the touchdown zone. The tower controller joked with us about the precision of the NDB approach and that he feels uncomfortable with aircraft at minimums coming towards the tower (and not the runway) but he continued to state that this is the way that this approach is usually flown.

Original NASA ASRS Text

Title: ACR TRACK DEV WHILE MAKING NDB APCH. POSSIBLE ACFT EQUIP PROB.

Narrative: WHILE ON THE NDB 31 APCH TO BTR, THE CTLR ASKED IF WE WERE ESTABLISHED ON THE APCH, WHICH WE WERE INDICATING, AND SUBSEQUENTLY CLRED US FOR THE APCH, WE CONTACTED TWR AND WERE ADVISED THAT WE APPEARED 1 MI S OF THE APCH COURSE, EVEN THOUGH THE BEARING ON MY RMI WAS FLUCTUATING PLUS OR MINUS 3 DEGS THE MEAN SHOWED US ON COURSE. I DID TAKE 10 DEGS OF CORRECTION TO GET ON COURSE THAT HE WOULD SHOW ON HIS BRIGHT SCOPE. WE GOT TO MINIMUMS AND TWR ASKED US TO RPT THE ARPT IN SIGHT. I HAD THE BEACON BUT NO RWY. THE TWR CTLR ADVISED US THAT HE HAD US IN SIGHT AND ABOUT THAT TIME THE RWY WAS FOUND. I CORRECTED TO THE R AND MADE AN UNEVENTFUL LNDG, BUT MY LNDG WAS MADE ABOUT 200 FT PAST THE TOUCHDOWN ZONE. THE TWR CTLR JOKED WITH US ABOUT THE PRECISION OF THE NDB APCH AND THAT HE FEELS UNCOMFORTABLE WITH ACFT AT MINIMUMS COMING TOWARDS THE TWR (AND NOT THE RWY) BUT HE CONTINUED TO STATE THAT THIS IS THE WAY THAT THIS APCH IS USUALLY FLOWN.

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.