THE PLT HAD POSTPONED THE FLT DUE TO WX CONDITIONS. DURING A FLT FROM DEMING, NM TO WACO, TX, THE ACFT SUBSEQUENTLY CRASHED WITHIN THE BOUNDRIES OF A PRIVATE ARPT, NORTHWEST OF EL PASO, TX. IMPACT OCCURRED IN A STEEP LEFT BANK, NOSE LOW ATTITUDE. THE DEGREE OF DISINTEGRATION OF THE WRECKAGE INDICATED THE ACFT WAS TRAVELING AT A HIGH RATE OF SPEED DURING IMPACT. NO PREIMPACT PART FAILURE OR MALFUNCTION WAS FOUND. THE ACCIDENT HAD OCCURRED DURING THE LAST STAGES OF HURRICANE ALICA. ABOUT 12 MI AWAY, THE 1850 MDT WX AT EL PASO WAS, IN PART: CLEAR, VISIBILITY 70 MI, WIND 250 DEG AT 4 KTS. HOWEVER, CUMULONIMBUS BUILDUPS WERE REPORTED IN ALL QUADRANTS & A UH-1 PLT REPORTED RAINSHOWERS & MODERATE TURBULENCE IN THE VICINITY OF THE CRASH SITE. A TOXICOLOGICAL CHECK OF THE PLT'S MUSCLE TISSUE FLUID SHOWED A CONCENTRATION OF 127MG% (.127%) ALCOHOL. THE PLT HAD VISION IN ONLY 1 EYE & WAS REQUIRED TO PERFORM A TEST OF DEMONSTRATED ABILITY ON EACH RENEWAL OF HIS MED CERT, BUT HE HAD FAILED TO DO SO; THEREFORE, HIS MED CERT WAS INVALID.