Narrative:

On dec/wed/03, aircraft X, a cessna 340, departed corpus christi, tx (crp) at approximately XA15 hours for el paso, tx (elp). A duats briefing was obtained. The departure and en route portions of the flight were unremarkable. After handoff from ZAB to elp approach, approach vectored aircraft X first to the south and then to the north of the VOR 081 degree radial for traffic. This was a VOR approach to runway 26L and was initially flown with the autoplt on in the heading mode with altitude hold engaged. About 12-15 mi east of the VOR at 6500 ft, aircraft X was cleared for the approach and instructed to track the 081 degree radial inbound. WX at the time was clear of immediate clouds (bases about 8500 ft MSL) but forward visibility was limited, although the ground was visible in dusk to dark transition lighting with moderate turbulence and relatively high winds and blowing dust. Close to intercepting the 081 degree radial, the pilot's attention was diverted by a smell in the cockpit not unlike an electrical overheat. However, there was no fire or smoke. The pilot's attention was diverted and the aircraft crossed south of the 081 degree radial by a 4 DOT deflection of the VOR. The pilot caught the tracking error and proceeded north to reintercept the 081 degree radial. About 1 min later, when the aircraft was about 2.2 mi from the VOR, ATC first advised of the tracking error and canceled the approach clearance and then almost immediately reinstated it as the aircraft was approaching the 081 degree radial. Compounding the problem, the tower issued a low altitude alert as the aircraft had descended below 5400 ft to about 5000 ft, between gifen intersection and the VOR. The pilot immediately disconnected the autoplt and climbed to 5400 ft and the rest of the approach was unremarkable. During this time, the aircraft was mostly clear of clouds and ground lights were visible. Contributing factors: smell of an electrical problem in the cockpit diverting the pilot's attention during a critical phase of flight, autoplt altitude hold malfunctioned when approach flaps were lowered, pilot's failure to more accurately monitor the approach course and altitude while checking for electrical problems. Corrective action: pilot will review CRM procedures and will fly more instrument approachs to sharpen his skills both in a simulator and in the aircraft.

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Original NASA ASRS Text

Title: C340 PLT HAD AN ALT AND TRACK DEV WHILE ATTEMPTING THE VOR RWY 26L APCH TO ELP.

Narrative: ON DEC/WED/03, ACFT X, A CESSNA 340, DEPARTED CORPUS CHRISTI, TX (CRP) AT APPROX XA15 HRS FOR EL PASO, TX (ELP). A DUATS BRIEFING WAS OBTAINED. THE DEP AND ENRTE PORTIONS OF THE FLT WERE UNREMARKABLE. AFTER HDOF FROM ZAB TO ELP APCH, APCH VECTORED ACFT X FIRST TO THE S AND THEN TO THE N OF THE VOR 081 DEG RADIAL FOR TFC. THIS WAS A VOR APCH TO RWY 26L AND WAS INITIALLY FLOWN WITH THE AUTOPLT ON IN THE HEADING MODE WITH ALT HOLD ENGAGED. ABOUT 12-15 MI E OF THE VOR AT 6500 FT, ACFT X WAS CLRED FOR THE APCH AND INSTRUCTED TO TRACK THE 081 DEG RADIAL INBOUND. WX AT THE TIME WAS CLR OF IMMEDIATE CLOUDS (BASES ABOUT 8500 FT MSL) BUT FORWARD VISIBILITY WAS LIMITED, ALTHOUGH THE GND WAS VISIBLE IN DUSK TO DARK TRANSITION LIGHTING WITH MODERATE TURB AND RELATIVELY HIGH WINDS AND BLOWING DUST. CLOSE TO INTERCEPTING THE 081 DEG RADIAL, THE PLT'S ATTN WAS DIVERTED BY A SMELL IN THE COCKPIT NOT UNLIKE AN ELECTRICAL OVERHEAT. HOWEVER, THERE WAS NO FIRE OR SMOKE. THE PLT'S ATTN WAS DIVERTED AND THE ACFT CROSSED S OF THE 081 DEG RADIAL BY A 4 DOT DEFLECTION OF THE VOR. THE PLT CAUGHT THE TRACKING ERROR AND PROCEEDED N TO REINTERCEPT THE 081 DEG RADIAL. ABOUT 1 MIN LATER, WHEN THE ACFT WAS ABOUT 2.2 MI FROM THE VOR, ATC FIRST ADVISED OF THE TRACKING ERROR AND CANCELED THE APCH CLRNC AND THEN ALMOST IMMEDIATELY REINSTATED IT AS THE ACFT WAS APCHING THE 081 DEG RADIAL. COMPOUNDING THE PROB, THE TWR ISSUED A LOW ALT ALERT AS THE ACFT HAD DSNDED BELOW 5400 FT TO ABOUT 5000 FT, BTWN GIFEN INTXN AND THE VOR. THE PLT IMMEDIATELY DISCONNECTED THE AUTOPLT AND CLBED TO 5400 FT AND THE REST OF THE APCH WAS UNREMARKABLE. DURING THIS TIME, THE ACFT WAS MOSTLY CLR OF CLOUDS AND GND LIGHTS WERE VISIBLE. CONTRIBUTING FACTORS: SMELL OF AN ELECTRICAL PROB IN THE COCKPIT DIVERTING THE PLT'S ATTN DURING A CRITICAL PHASE OF FLT, AUTOPLT ALT HOLD MALFUNCTIONED WHEN APCH FLAPS WERE LOWERED, PLT'S FAILURE TO MORE ACCURATELY MONITOR THE APCH COURSE AND ALT WHILE CHKING FOR ELECTRICAL PROBS. CORRECTIVE ACTION: PLT WILL REVIEW CRM PROCS AND WILL FLY MORE INST APCHS TO SHARPEN HIS SKILLS BOTH IN A SIMULATOR AND IN THE ACFT.

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.