SMA FORCED LNDG DUE TO LOW OIL PRESSURE.

Narrative

PLT/OWNER INADVERTENTLY LEFT SCREWDRIVER ON COOLING AIR BAFFLE JUST FORWARD OF THE OIL COOLER. AFTER ABOUT 40 MINS OF FLT THE SCREWDRIVER WORKED A HOLE IN THE OIL COOLER. A LIGHT OILEY SMOKE WAS NOTICED IN THE CABIN AND OIL PRESSURE BEGAN TO DROP. WHEN OIL PRESSURE REACHED BOTTOM OF THE GREEN; PWR REDUCED TO IDLE; ROAD SELECTED FOR LNDG. PAX (ALSO A PLT) CONTACTED ACR FLT ON 121.5. THEY RELAYED TO ZDV PERTINENT INFO. ACFT LANDED ON THE ENTRY ROAD OF A HAZARDOUS WASTE DUMP. THE DUMP WAS UNDER CONSTRUCTION AND NOT OPEN. ON FINAL APCH PLT ADDED PWR TO GET OVER THE CLOSED GATE AND LANDED. NO DAMAGE; NO INJURIES. NEXT DAY REPLACED COOLER; ADDED OIL AND RETURNED TO APA. 2 ITEMS IN PLT TRNING COULD HAVE PREVENTED THE FORCED LNDG AND MADE THE FORCED LNDG SAFER: 1) THE PLT COMPLETED PLT TRNING AT A FLT SCHOOL IN 1/86. THE SCHOOL WOULD ALLOW NO MAINT BY THE STUDENTS. CONSEQUENTLY; WHEN THE PLT PURCHASED THE ACFT IN 4/88 HE HAD NO TRNING IN THE BASICS OF FAR PART 43 MAINT; NOR IN THE MOST BASIC MECHS SAFETY PRACTICES. THESE SHOULD BE TAUGHT. 2) PLT'S TRNING FOR FORCED LNDG WAS BY MEMORY OF A MENTAL CHKLIST. DURING THIS FORCED LNDG; EVEN THOUGH EMER CHKLISTS WERE AT HAND; THE TRNING TOOK OVER AND THE PLT DREW A BLANK. PLT TRNING SHOULD EMPHASIZE USE OF A CHKLIST FOR EMERS RATHER THAN MEMORY.