ACFT EQUIP PROB. NO OIL PRESSURE FORCED LNDG.

Narrative

I WAS CRUISING AT 3000 FT MSL WITH A STUDENT. I AM A CFI. I NOTICED THE OIL PRESSURE DROP TO ZERO. THE TERRAIN WE WERE OVERFLYING HAS AN AVERAGE ALT OF 1300 FT MSL. THE AIR BASE WE FLEW OUT OF; WAS PLUS OR MINUS 15 NM TO THE S. TO GET THERE; WE HAVE TO OVERFLY SEVERAL VILLAGES AND HILLY TERRAIN WITH HARDLY ANY SUITABLE EMER FIELDS/PASTURES TO LAND. I THEREFORE OPTED TO LAND ON THIS 1 GRASS STRIP (PRIVATELY OWNED) WHILE I STILL HAD PWR AVAILABLE. OTHER THAN THE AIR BASE (15 NM S) THERE ARE NO FIELDS IN THE VICINITY. SO; ONCE AGAIN; I OPTED TO LAND CTLED ON THIS GRASS STRIP; RATHER THAN TRY TO RETURN TO THE AIR BASE AND LAND IN ONE OF THE MANY SMALL VILLAGES OR ON UNSUITABLE TERRAIN OR OVER PWR LINES; ETC. I TOLD THE STUDENT THAT I WAS IN CTL OF THE AIRPLANE AND PROCEEDED TO CALL RAMSTEIN (AIR BASE) TWR TO INFORM THEM OF MY WHEREABOUTS AND THAT WE WERE GOING TO LAND BECAUSE OF TOTAL LOSS OF OIL PRESSURE. I HAD ALREADY ESTABLISHED BEST GLIDE SPD; PUT THE FUEL PUMP ON; SWITCHED TO THE FULLEST FUEL TANK; MIXTURE FULL RICH; SECURED SEAT BELTS; AND WAS HEADING TOWARD THE GRASS STRIP. I THEN SQUAWKED 7700 ON THE XPONDER. AS WE WERE APCHING THE FIELD; I REALIZED THAT WE WERE GOING TO LAND WITH A TAILWIND. I ADVANCED THE THROTTLE; TO SEE IF I STILL HAD PWR AND THE ENG SEEMED TO BE RUNNING A LITTLE ROUGH. I DECIDED TO PROCEED WITH THE LNDG; RATHER THAN GAR AND LOSE PWR AND LAND IN THE UNSUITABLE TERRAIN SURROUNDING THE FIELD (HILLS; HIGH GRASS/CORN; TREES; PWR LINES). WE TOUCHED DOWN WITH FULL FLAPS PLUS OR MINUS 5 KTS ABOVE STALL SPD. THE TAILWIND WAS 10 KTS WITH GUSTS 15-25 KTS. WE MAINTAINED DIRECTIONAL CTL AND APPLIED HVY BRAKING; KEEPING THE NOSE UP AND WENT STRAIGHT AHEAD; OFF THE GRASS STRIP AND INTO A PLOWED FIELD. THE MAIN GEAR SHEARED OFF AND WE CAME TO A STOP. THE NOSE GEAR; PROP AND ENG (EXTERNAL) ARE INTACT. THE WINGS AND FUEL TANKS DID NOT RUPTURE. THE FLAPS ARE DAMAGED. WE DID NOT SUFFER ANY INJURIES WHATSOEVER. RESEARCH IS BEING DONE ON WHAT CAUSED THE OIL PRESSURE TO DROP.