APRX 35 MIN AFTER THE ACFT TKOF, WITNESSES OBSERVED IT IN WHAT THEY DESCRIBED AS ERRATIC FLT. ONE WITNESS RPRTD THE ACFTFLEW OVER A VACANT FIELD WHERE IT ENTERED A STEEP CLIMB, THEN STALLED & IMPACTED THE GND IN A STEEP NOSE DOWN ATTITUDE. NO PREIMPACT PART FAILURE OR MALFUNCTION WAS FND. THE PLT HAD LOGGED 7 HRS OF FLT TIME, BUT HAD NOT OBTAINED AN FAA MEDICAL/STUDENT PLT CERTIFICATE. APRX 1 MONTH BFR THE ACDNT, HE HAD PURCHASED THE ACFT FM A CO-WORKER, WHO HAD ALLOWED HIM TO MAKE TKOFS & LNDS. HOWEVER, THE PLT HAD NOT YET RECEIVED TRAINING IN TKOFS & LNDGS FM A CERTIFIED FLT INSTRUCTOR (CFI). TWO CHECKS OF THE PLT'S BLOOD SHOWED ALCOHOL LVLS OF 0.30% & 0.32%. A CHECK OF HIS URINE SHOWED 0.18% ALCOHOL. HE HAD A RPRTD HISTORY OF ALCOHOL ABUSE & WAS HOSPITALIZED ON 7/20/87 WITH ACUTE DELIRIUM, HEPATORENAL SYNDROME, HYPER- TENSION, & ACUTE RENAL FAILURE. ON 7/24/87, HE WAS RLSD FM THE HOSPITAL & IMIPRAMINE WAS PRESCRIBED. TOX TESTS CONFIRMEDIMIPRAMINE IN PLTS BLOOD. DRUG HAS ADVERSE SIDE EFFECTS INCLUDING MENTAL CONFUSION, ANXIETY, BLURRED VISION & SEIZURES.