BE35 pilot deviates from cleared track in cle airspace after incorrect input to navigation computer.

Attributes
ACN	421830
Time
Date	199812
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bkl
State Reference	OH
Altitude	msl bound lower : 3000 msl bound upper : 5000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Bonanza 35
Operating Under FAR Part	Part 91
Route In Use	departure other enroute : direct enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument
Experience	flight time last 90 days : 53 flight time total : 2400 flight time type : 2100
ASRS Report	421830
Person 2
Affiliation	government : faa
Function	controller : departure
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other controllera
Resolutory Action	other
Consequence	Other
Supplementary
Air Traffic Incident	Pilot Deviation

Narrative:

Departed bkl on IFR clearance. Cleared to fails intersection, then direct hfd. Given vector northbound 010 degrees. Later cleared direct fails intersection. Input direct fails into my computer. Bearing given was sbound, so I assumed I was already north of fails. Turned to sbound heading, approximately 180 degrees. Sometime during this time there was a controller (frequency) change. Controller called, 'are you heading direct fails?' 'turn to 360 degree heading.' proceeded to intersection, finished trip. Probable cause: figured out that flight plan was not activated in the computer, so 'direct to' instruction defaulted to the airport, its last destination. Also, I managed to rationalize the rest of the information (VOR/DME, etc) during this brief period. I have used this same equipment for many yrs, and undoubtedly have come to depend too heavily on its direction. Corrective action: must check instrumentation feedback when inputting data to make sure it is entered correctly. Be sure that backup information agrees with primary navigation equipment. Be always aware that tendency is to look at information presented and force it to fit our beliefs.

Original NASA ASRS Text

Title: BE35 PLT DEVIATES FROM CLRED TRACK IN CLE AIRSPACE AFTER INCORRECT INPUT TO NAV COMPUTER.

Narrative: DEPARTED BKL ON IFR CLRNC. CLRED TO FAILS INTXN, THEN DIRECT HFD. GIVEN VECTOR NBOUND 010 DEGS. LATER CLRED DIRECT FAILS INTXN. INPUT DIRECT FAILS INTO MY COMPUTER. BEARING GIVEN WAS SBOUND, SO I ASSUMED I WAS ALREADY N OF FAILS. TURNED TO SBOUND HDG, APPROX 180 DEGS. SOMETIME DURING THIS TIME THERE WAS A CTLR (FREQ) CHANGE. CTLR CALLED, 'ARE YOU HDG DIRECT FAILS?' 'TURN TO 360 DEG HDG.' PROCEEDED TO INTXN, FINISHED TRIP. PROBABLE CAUSE: FIGURED OUT THAT FLT PLAN WAS NOT ACTIVATED IN THE COMPUTER, SO 'DIRECT TO' INSTRUCTION DEFAULTED TO THE ARPT, ITS LAST DEST. ALSO, I MANAGED TO RATIONALIZE THE REST OF THE INFO (VOR/DME, ETC) DURING THIS BRIEF PERIOD. I HAVE USED THIS SAME EQUIP FOR MANY YRS, AND UNDOUBTEDLY HAVE COME TO DEPEND TOO HEAVILY ON ITS DIRECTION. CORRECTIVE ACTION: MUST CHK INSTRUMENTATION FEEDBACK WHEN INPUTTING DATA TO MAKE SURE IT IS ENTERED CORRECTLY. BE SURE THAT BACKUP INFO AGREES WITH PRIMARY NAV EQUIP. BE ALWAYS AWARE THAT TENDENCY IS TO LOOK AT INFO PRESENTED AND FORCE IT TO FIT OUR BELIEFS.

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.