A PA44 pilot enters the wrong ILS frequency resulting in the aircraft being slightly off course.

Attributes
ACN	524340
Time
Date	200109
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : oak.airport
State Reference	CA
Altitude	msl bound lower : 700 msl bound upper : 2100
Environment
Light	Night
Aircraft 1
Controlling Facilities	tower : oak.tower
Operator	general aviation : personal
Make Model Name	PA-44 Seminole Turbo Seminole
Flight Phase	descent : intermediate altitude descent : approach
Route In Use	approach : instrument precision arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : multi engine pilot : commercial pilot : instrument
Experience	flight time last 90 days : 40 flight time total : 625 flight time type : 18
ASRS Report	524340
Events
Anomaly	aircraft equipment problem : less severe other anomaly other spatial deviation
Resolutory Action	controller : issued advisory flight crew : became reoriented
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Returning from pleasure/training flight OQ5, we were vectored in to intercept the ILS approach oak and were cleared for the ILS, switched to oak tower. Our HSI needle was responding and we began the descent from +/-2000 ft. We responded to the gauge indications, but at about 800 ft AGL lost the flag (signal). The tower called us about 700 ft and reported we were 1 mi southwest of the ILS. We then broke out of fog and with the airport in sight, landed ok. Upon landing we determined that the incorrect ILS frequency was set.

Original NASA ASRS Text

Title: A PA44 PLT ENTERS THE WRONG ILS FREQ RESULTING IN THE ACFT BEING SLIGHTLY OFF COURSE.

Narrative: RETURNING FROM PLEASURE/TRAINING FLT OQ5, WE WERE VECTORED IN TO INTERCEPT THE ILS APCH OAK AND WERE CLRED FOR THE ILS, SWITCHED TO OAK TWR. OUR HSI NEEDLE WAS RESPONDING AND WE BEGAN THE DSCNT FROM +/-2000 FT. WE RESPONDED TO THE GAUGE INDICATIONS, BUT AT ABOUT 800 FT AGL LOST THE FLAG (SIGNAL). THE TWR CALLED US ABOUT 700 FT AND RPTED WE WERE 1 MI SW OF THE ILS. WE THEN BROKE OUT OF FOG AND WITH THE ARPT IN SIGHT, LANDED OK. UPON LNDG WE DETERMINED THAT THE INCORRECT ILS FREQ WAS SET.

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.