PA-44 SEMINOLE'S R GEAR COLLAPSES DURING TOUCH AND GO LNDG.

Narrative

WE WERE ATTEMPTING A TOUCH AND GO AND AFTER LNDG AND ROLLING OUT THE R MAIN LNDG GEAR COLLAPSED WITH 3 GREEN LIGHTS AND GEAR DOWN. ALL 3 WHEELS WERE ON THE GND. PLANE STARTED TO DRIFT TO THE R AND THEN; WITHOUT WARNING; IT JUST COLLAPSED. ALL WE COULD DO WAS RIDE IT OUT AND PULL ALL THROTTLES BACK AND TURN OFF ALL SWITCHES. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT THE STUDENT PLT HE WAS TRAINING WAS A RETIRED AIR FORCE CAPT WHO HAD FLOWN SINCE WORLD WAR II; BUT ONLY IN A C-172 AND WASN'T FAMILIAR WITH THE PA-44 TWIN. DURING THE TOUCH AND GO THE INSTRUCTOR ASKED FOR THE FLAPS UP AND THE STUDENT REACHED AND TOUCHED THE GEAR HANDLE. THE INSTRUCTOR PLT SAID; 'NO' TO HIM AS HE COULDN'T REACH HIS HAND. THE RPTR DOESN'T FEEL THAT THE OTHER PLT MOVED THE SELECTOR AND THE GEAR INDICATIONS DID NOT CHANGE FROM THE 3 GREENS. THE POSTFLT INSPECTION SHOWED NO GEAR MALFUNCTIONS. RPTR STATED THAT THE MECHS DID PERFORM AN 'AB' ON THE ACFT'S LNDG GEAR BUT DID NOT KNOW; NOR WAS HE INFORMED; IF THAT 'AB' HAD ANYTHING TO DO WITH THE R GEAR COLLAPSING. AFTER THE ACFT WAS BACK IN SVC THE RPTR AND ANOTHER INSTRUCTOR PLT LOOKED THE GEAR OVER AND NOTED THAT THE 'SQUAT SWITCH' WAS RATHER TIRED LOOKING AND RUSTY. BOTH FEEL THAT PERHAPS THE GEAR HANDLE MIGHT HAVE BEEN HIT AND THE SQUAT SWITCH FAILED IN ITS FUNCTION IN KEEPING THE GEAR FROM AFFECTING THE SENSING ON THE UP MECHANISM OF THE GEAR. FLAPS WERE STILL DOWN SO THE FULL WT OF THE ACFT WAS NOT ON THE GEAR; ANOTHER FACTOR TO CONSIDER.