SMA MAKING UNSCHEDULED LNDG LANDS GEAR UP.

Narrative

WX BRIEFING -- FTW FSS AT X15 PM 5000 SCATTERED; 10000 SCATTERED VISIBILITY 13 IMPROVING TO 5500 SCATTERED VISIBILITY UNLIMITED IN SAT. RTE -- DALLAS ADDISON DIRECT WACO V17 AUSTIN SAN ANTONIO; TX. WX UPDATE -- SAN ANGELO FSS 122.55 X+4:30 PM LCL AUSTIN BASICALLY CLR AND AUSTIN ATIS BASICALLY CLR. EVENTS -- 10-20 MI N OF AUSTIN CEILING FORMED AT 5000 FT THEN LOWERED TO 4000 FT. VISIBILITY DROPPED TO 5-7 MI. CHOSE TO DSND TO 4000 FT IN ARSA RATHER THAN 60 VFR ON TOP IN UNFORCAST WX; ON MOONLESS NIGHT; CLOUDS ABOVE AND WARM HUMID SOUTHERLY FLOW. CALLED APCH. VISIBILITY AHEAD DROPPED; CEILING LOWERED; I DSNDED TO 3500 FT. ELECTED TO DISCONTINUE TRIP AND LAND AT MUELLER ARPT. PREPARED FOR APCH; VECTORED TO FINAL; ARPT SIGHTED AT TURN TO FINAL APPROX 2 MI OUT. SWITCHED TO AUSTIN TWR; REMEMBER RUNNING CHKLIST AND CAPTURING VASI; APCH SPD 90; THEN 80 THEN PROLONGED FLAIR AND SMOOTH LNDG; WHEELS UP. CONTRIBUTING FACTORS: WX. RUSHED APCH. GEAR UP WARNING HORN AND RED LIGHT DID NOT FUNCTION AT PRESCRIBED POINTS (105 MPH AND 14 INCH MP). AUTO GEAR EXTENSION LATCHED OFF BY PRIOR USER (IT IS NOT A CHKLIST ITEM; BUT WILL BE FOR ME). AUTO GEAR EXTENSION OFF. WARNING LIGHT DID ILLUMINATE TO WARN OF ABOVE.