PLT OF A JET CESSNA SINGLE PLT CITATION FAILED TO FOLLOW PROPOSED APCH TRACK DUE TO MISINTERP OF THE DME READOUT.

Narrative

FLYING SINGLE-PLT IN A CITATION 501; FROM A POS ABOUT 50 NM SE OF MENA; AR; I WAS CLRED DOWN TO 4000 FT; DIRECT TO THE MENA NDB AND CLRED FOR THE NDB-A APCH. THIS REQUIRED ABOUT A 330 DEG HDG TO THE NDB; THEN A R TURN TO FLY OUTBOUND ON THE 080 DEG BEARING. I WAS USING THE ADF NEEDLE FOR PRIMARY GUIDANCE; BACKED UP BY A GPS INSTALLED IN THE ACFT. I ALSO HAD THE DME SET TO THE RICH MOUNTAIN VOR; THIS WAS THE BASIS OF THE PROB THAT FOLLOWED. IN THIS ACFT; THE DME DISPLAYS MILEAGE ON ITS FACE AND ALSO ON THE PLT'S HSI; EVEN IF THE GPS IS COUPLED TO THE HSI. IN ANOTHER CITATION THAT I HAVE BEEN FLYING WITH SIMILAR AVIONICS BUT A DIFFERENT GPS; DME MILEAGE IS DISPLAYED ON THE PLT'S HSI UNLESS THE GPS IS COUPLED; AND THEN IT DISPLAYS MILEAGE TO THE SELECTED GPS WAYPOINT. I MISSED THE FACT THAT IN THE INCIDENT ACFT; THE HSI MILEAGE WAS ALWAYS TO THE VOR; NEVER TO THE GPS WAYPOINT. INBOUND TO THE NDB; I NOTED THE MILEAGE ON THE HSI AS ABOUT 30 NM. IN MY MIND WE WERE 30 NM FROM THE NDB. THE GPS WAYPOINT WAS ON THE ARPT; WHERE THE NDB IS ALSO LOCATED. IN REALITY; WE WERE ONLY ABOUT 9 NM FROM THE NDB; BUT I WAS NOT LOOKING AT THE MILEAGE DISPLAY ON THE GPS AND DID NOT CATCH THIS. FURTHER; I SOMEHOW MISSED SEEING THE ADF NEEDLE SWING AS I OVERFLEW THE STATION. AT THIS POINT I WAS TRYING TO FIGURE OUT WHY THE #2 NEEDLE ON THE RMI WAS NOT POINTING TO THE STATION AND BELIEVE THIS DISTRACTED ME FROM THE NAV SIT; THOUGH IT IS NO EXCUSE. WHEN THE HSI MILEAGE WAS DOWN TO ABOUT 12 MI IT SUDDENLY DAWNED ON ME THAT THE ADF NEEDLE HAD REVERSED. AT THIS POINT I WAS ABOUT 9 MI PAST THE NDB; OR NW OF IT; STILL ON A HDG OF ABOUT 330 DEGS; AND STILL LEVEL AT 4000 FT. I STARTED A R TURN BACK TO THE STATION; ABOUT THE TIME THE CTR CALLED TO ASK WHERE WE WERE GOING. THE CTLR RECLRED ME FOR THE APCH AND ASKED THAT WE CANCEL THE IFR BEFORE LNDG OR BY PHONE AFTER LNDG. I COMPLETED THE NDB APCH AND LANDED BUT THEN; PREOCCUPIED WITH THE PROCEDURAL ERROR; FORGOT TO CALL THE CTR AND CANCEL. THEY HAD TO CALL THE ARPT TO SEE IF WE HAD LANDED. I DON'T BELIEVE THERE WAS ANY LOSS OF SEPARATION; AND TERRAIN CLRNC WAS AT LEAST ADEQUATE THROUGHOUT THIS; BUT THERE WAS A LOSS OF SITUATIONAL AWARENESS ON MY PART FOR AT LEAST 3 MINS. I STILL CAN'T BELIEVE I LET THIS HAPPEN. IT IS SOBERING TO THINK OF WHAT THE RESULT COULD HAVE BEEN. THE PROB AROSE FROM A MISUNDERSTANDING OF HOW THE EQUIP OPERATED. CONTRIBUTING FACTORS WERE THE FACT I HAVE FLOWN INTO THIS ARPT MANY TIMES OVER THE LAST 15 YRS; NEARLY ALWAYS USING THE RICH MOUNTAIN VOR FOR MILEAGE GUIDANCE; THE FACT THAT I HAVE BEEN FLYING ANOTHER CITATION WITH A DIFFERENT MILEAGE SETUP ON THE HSI; AND THE FACT I WAS FLYING SINGLE-PLT. THOUGH I AM A FIRM BELIEVER IN THE SAFETY OF SINGLE-PLT CITATION OPS WITH A PROPERLY TRAINED PLT; THIS INCIDENT POINTS UP THE VALUE OF A SECOND PLT TO CATCH AN ERROR LIKE THIS. I WILL IN THE FUTURE PAY A LOT MORE ATTN TO SETTING UP THE NAV EQUIP FOR AN APCH; AND SPEND MORE TIME FOCUSED ON THE NAV SIT AND LESS TIME STUDYING NON- ESSENTIAL ITEMS THAT COULD BE FIGURED OUT LATER.