BE76 INSTRUCTOR AND TRAINEE HAD LNDG GEAR COLLAPSE ON LNDG.

Narrative

DURING TRAINING FOR A MULTI-ENG COMMERCIAL STUDENT; I PUT A BEECHCRAFT DUCHESS ON ITS BELLY DURING A SINGLE ENG LNDG. I SIMULATED AN ENG FAILURE ON THE UPWIND LEG OF THE PATTERN. MY STUDENT DEALT WITH THE SIMULATED FAILURE AS I HAD TRAINED HIM. TURNED BASE; MY STUDENT EXTENDED THE LNDG GEAR; AND WE BOTH OBSERVED 3 GREEN LIGHTS INDICATING THE GEAR WAS DOWN AND LOCKED. A NORMAL LNDG WAS ASSUMED. A GEAR COLLAPSE WAS SUSPECTED AS THE AIRPLANE SMOOTHLY TOUCHED DOWN ON THE RWY. THE ONLY DAMAGE DONE TO THE ACFT WAS BENT PROPS; AND MINOR SKIN DAMAGE; BUT NO STRUCTURAL DAMAGE WHATSOEVER. AFTER THE AIRPLANE CAME TO A STOP; I TURNED THE FUEL SELECTORS OFF; MOVED THE MIXTURE CTLS TO IDLE CUT-OFF; SHUT DOWN FUEL PUMPS; MAGNETOS; BATTERY AND MASTER SWITCHES; THEN ORDERED MY STUDENT TO EXIT THE PLANE IMMEDIATELY. PRIOR TO THAT; MY STUDENT WAS THE SOLE MANIPULATOR OF THE CTLS. IN MY JUDGEMENT; NOTHING AFFECTED THE PERCEPTIONS OF MY STUDENT; NOR MYSELF. IT WAS ROUTINE TRAINING; OF A NORMAL DURATION; AND WX WAS NO FACTOR.