C150 FLAPS DO NOT FULLY RETRACT WHILE PRACTICING SOFT FIELD LNDGS.

Narrative

DURING THE EXECUTION OF A SHORT FIELD LNDG MY STUDENT RETRACTED THE FLAPS TO THE 0 DEG POS. AFTER THE ACFT HAS STOPPED; HE EXECUTED A SOFT FIELD TKOF WITH 4900 FT OF RWY THAT REMAINED AHEAD. A SOFT FIELD TKOF IN A C150 REQUIRES 10 DEGS OF FLAPS; SO 10 DEGS OF FLAPS WAS APPLIED. DURING THE TKOF; THE STUDENT DRIFTED ABOVE GND EFFECT AND THE PLANE COULD NOT CLB AT A SUFFICIENT RATE TO FLY THE NORMAL PATTERN. AFTER THE PLANE WAS APPROX 300 FT AGL AND XING THE END OF THE RWY; I TOOK THE PLANE BECAUSE A POSITIVE RATE OF CLB WAS NOT ESTABLISHED. I QUICKLY RECOGNIZED THAT THE FLAPS WERE STUCK IN THE ALMOST FULL DOWN POS WHICH WAS CAUSING FOR SUCH POOR CLB PERFORMANCE. I QUICKLY CHKED CIRCUIT BREAKERS AND RECYCLED THE FLAP LEVER; BUT FLAPS DID NOT MOVE. THE ONLY OPTION WAS TO CIRCLE BACK FOR THE RWY I DEPARTED ON AT AN ALT OF 300 FT AGL. I CALLED TWR AND EXPLAINED THE SIT AND WAS CLRED TO LAND ON RWY 30 -- THE OPPOSITE THAT I HAD DEPARTED FROM. AFTER SECURING THE AIRPLANE I HAD FIGURED OUT THAT THE FLAPS DID NOT RETRACT BUT ONLY 5 OR SO DEGS AFTER EXECUTING THE SHORT FIELD LNDG. MY SUGGESTION IS TO RESTRICT THE INSPECTION TOLERANCES ON THE FLAP SYS OF THE C150 OR TO FIGURE A WAY TO FIX THIS PROB. FROM WHAT I HEAR; THE FLAPS FAIL FREQUENTLY ON THIS TYPE OF ACFT.