PIPER PA23 INSTRUCTOR; WITH INST TRAINEE; OVERFLEW A CLOSED RWY DURING A MISSED APCH TO THE CLOSED RWY CONTRARY TO ATC PUBLISHED PROCS.

Narrative

WE WERE ON AN INST TRAINING FLT AND CLRED FOR THE PRACTICE VOR RWY 9 APCH. THE STUDENT SHOT THE APCH AND EXECUTED A MISSED APCH AT THE MISSED APCH POINT WHICH WAS THE OSH VOR LOCATED ABOUT MIDFIELD. THE TWR THEN ASKED US IF WE WERE ON APCH FOR RWY 18; WE REPLIED 'NEGATIVE' WE ARE IN A L TURN NBOUND AS PREVIOUSLY REQUESTED AND CLRED AFTER THE VOR RWY 9 APCH. THE TWR THEN ASKED IF WE HAD OVERFLOWN RWY 9 SINCE IT WAS CLOSED. I REPLIED 'AFFIRMATIVE' WE FLEW THE VOR RWY 9 APCH AS PREVIOUSLY CLRED TO THE MISSED APCH POINT WHICH ENTAILS FLYING OVER ABOUT 1/2 OF RWY 9. THE TWR RESPONDED THAT THEY NORMALLY DON'T ALLOW OVERFLYING A CLOSED RWY. I DID NOT DEBATE THE SIT FURTHER SINCE THE CTLR WAS BUSY AT A VFR ARPT WITH LIMITED VISIBILITY. I KNOW THAT FLYING AN APCH TO A CLOSED RWY IS FINE; BUT I AM NOT SURE WHAT THE TWR WAS COMING FROM IN HIS QUESTIONING OUR OVERFLYING OF THE RWY. I FEEL THAT IF THE TWR DID NOT WANT US FLYING THE ENTIRE APCH HE SHOULD HAVE MADE THAT CLR WHEN HE CLRED US FOR THE APCH.