DRG AN ILLEGAL DRUG OPN AT NGT, THE ACFT CRASHED IN THE EVERGLADES, ABT 16 MI SE OF NAPLES, FL. SURVEILLANCE PSNL IN THEAREA SAID THE VIS WAS LESS THAN 1/2 MI WITH FOG/SMOKE. ABT 3 HRS EARLIER, THE NAPLES WX WAS, IN PART: SKY PARTLY OBSCD, VIS 3 MI, WND CALM. INV REVEALED THE ACFT IMPACTED IN A SLIGHT L WING DWN, NOSE LOW, ATTITUDE, THEN BOUNCED & HIT A TREEBFR COMING TO REST ABT 270' FM THE INITIAL IMPACT PT. NO PREIMPACT MECH PROBLEM WAS EVIDENT. IN 1978, THE PLT WAS DENIEDA 1ST CLASS MED CERT DUE TO HEART DISEASE, DETECTED BY AN ELECTROCARDIOGRAM. LTR, HE GOT A 3RD CLASS MED CERT (USING AN-OTHER NAME, DOB & SSN), WHICH DID NOT REQUIRE AN ELECTROCARDIOGRAM. HIS LAST MED CERT (USING AN ALIAS) WAS DATED 8/5/86.AN AUTOPSY SHOWED HE HAD ADVANCED HEART DISEASE. MED EXAMINER BELIEVED A MASSIVE MYOCARDIAL INFARCT OR INCAPACITATING CARDIAC ARRHYTHMIA WAS A DISTINCT POSSIBILITY, BUT NO DRCT EVIDENCE OF EITHER WAS FND. A TOX CHECK OF VITREOUS FLUID SHOWED COCAINE & BENZOYLECGONINE LVLS OF 1490 & 782 NG/ML. DRUG/ALCOHOL TESTS OF KIDNEY & LIVER SPECIMENS WERE NEGATIVE.