Narrative:

I departed tmb with my instructor for a local instrument lesson. After takeoff we climbed northwest, and at this time we were informed by tower that they were not receiving our mode C. My instructor, who handled all communications throughout the flight, recycled the transponder and hit it a couple of times hoping to remedy the problem. A similar problem was remedied on a previous flight by this method due to the transponder being positional. After this was done the reply light began to flash. Believing that the problem was fixed, tower was notified. At the time, as well as throughout the entire flight, my attention was fixated solely on flying the plane and doing what was asked of me by the instructor. Tower then said that they were still not receiving a signal from us. My instructor had me continue the flight. It was later stated to me by my instructor that sometimes a transponder will go out, only to come back on line 10 mins later. Maybe this was the reason my instructor had me continue the flight. If I had a little more experience with the instrument flying I could have realized what had transpired, and acted appropriately by discontinuing the flight immediately. Roughly 15-20 mins later my instructor contacted miami approach to see if they could work us in a few approachs to tamiami. Approach then responded by informing us that they were not receiving our mode C. The transponder was again recycled by my instructor. Approach said they still had no signal from us. My instructor then asked approach if they could fit us in for an approach without it. Approach then had us turn for identify, and followed with vectors for the approach. After shooting the approach and going missed approach was contacted and informed of our position. We were instructed to land due to the fact that we did not have a mode C waiver. Tamiami tower was contacted and notified that we intended to land, and that we were going to take it out a little further west to get past krome avenue. At this time we were around 1300 ft after making a southwest turn out from runway 9R. My instructor then informed me to continue west past krome avenue. Tower contacted us moments later and informed us that they received a call from miami approach instructing us to land. The transmission was confirmed and we landed as soon as possible. After the flight was completed I realized the mistakes that were made, such as not turning back to land when first notified of our mode C problem. I also realized that my own ignorance of the situation and my 'instructor knows best attitude,' precluded me from ending the situation before it got worse.

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Original NASA ASRS Text

Title: INSTRUCTOR OF AN INST TRAINING FLT FAILED TO LAND AFTER BEING DENIED BY ATC PERMISSION TO OPERATE IN THE CLASS B AIRSPACE WITH AN INOP XPONDER.

Narrative: I DEPARTED TMB WITH MY INSTRUCTOR FOR A LCL INST LESSON. AFTER TKOF WE CLBED NW, AND AT THIS TIME WE WERE INFORMED BY TWR THAT THEY WERE NOT RECEIVING OUR MODE C. MY INSTRUCTOR, WHO HANDLED ALL COMS THROUGHOUT THE FLT, RECYCLED THE XPONDER AND HIT IT A COUPLE OF TIMES HOPING TO REMEDY THE PROB. A SIMILAR PROB WAS REMEDIED ON A PREVIOUS FLT BY THIS METHOD DUE TO THE XPONDER BEING POSITIONAL. AFTER THIS WAS DONE THE REPLY LIGHT BEGAN TO FLASH. BELIEVING THAT THE PROB WAS FIXED, TWR WAS NOTIFIED. AT THE TIME, AS WELL AS THROUGHOUT THE ENTIRE FLT, MY ATTN WAS FIXATED SOLELY ON FLYING THE PLANE AND DOING WHAT WAS ASKED OF ME BY THE INSTRUCTOR. TWR THEN SAID THAT THEY WERE STILL NOT RECEIVING A SIGNAL FROM US. MY INSTRUCTOR HAD ME CONTINUE THE FLT. IT WAS LATER STATED TO ME BY MY INSTRUCTOR THAT SOMETIMES A XPONDER WILL GO OUT, ONLY TO COME BACK ON LINE 10 MINS LATER. MAYBE THIS WAS THE REASON MY INSTRUCTOR HAD ME CONTINUE THE FLT. IF I HAD A LITTLE MORE EXPERIENCE WITH THE INST FLYING I COULD HAVE REALIZED WHAT HAD TRANSPIRED, AND ACTED APPROPRIATELY BY DISCONTINUING THE FLT IMMEDIATELY. ROUGHLY 15-20 MINS LATER MY INSTRUCTOR CONTACTED MIAMI APCH TO SEE IF THEY COULD WORK US IN A FEW APCHS TO TAMIAMI. APCH THEN RESPONDED BY INFORMING US THAT THEY WERE NOT RECEIVING OUR MODE C. THE XPONDER WAS AGAIN RECYCLED BY MY INSTRUCTOR. APCH SAID THEY STILL HAD NO SIGNAL FROM US. MY INSTRUCTOR THEN ASKED APCH IF THEY COULD FIT US IN FOR AN APCH WITHOUT IT. APCH THEN HAD US TURN FOR IDENT, AND FOLLOWED WITH VECTORS FOR THE APCH. AFTER SHOOTING THE APCH AND GOING MISSED APCH WAS CONTACTED AND INFORMED OF OUR POS. WE WERE INSTRUCTED TO LAND DUE TO THE FACT THAT WE DID NOT HAVE A MODE C WAIVER. TAMIAMI TWR WAS CONTACTED AND NOTIFIED THAT WE INTENDED TO LAND, AND THAT WE WERE GOING TO TAKE IT OUT A LITTLE FURTHER W TO GET PAST KROME AVENUE. AT THIS TIME WE WERE AROUND 1300 FT AFTER MAKING A SW TURN OUT FROM RWY 9R. MY INSTRUCTOR THEN INFORMED ME TO CONTINUE W PAST KROME AVENUE. TWR CONTACTED US MOMENTS LATER AND INFORMED US THAT THEY RECEIVED A CALL FROM MIAMI APCH INSTRUCTING US TO LAND. THE XMISSION WAS CONFIRMED AND WE LANDED AS SOON AS POSSIBLE. AFTER THE FLT WAS COMPLETED I REALIZED THE MISTAKES THAT WERE MADE, SUCH AS NOT TURNING BACK TO LAND WHEN FIRST NOTIFIED OF OUR MODE C PROB. I ALSO REALIZED THAT MY OWN IGNORANCE OF THE SIT AND MY 'INSTRUCTOR KNOWS BEST ATTITUDE,' PRECLUDED ME FROM ENDING THE SIT BEFORE IT GOT WORSE.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.