Narrative:

Problem began when controller advised us of a single-engine making an approach to a parallel runway 13L. I instructed my student that I would find the traffic and keep it in sight since my student was flying the aircraft and handling the communications. I was somewhat distracted because of the other aircraft, which we had in sight. Our initial communications with radar controllers were that we would perform ILS approach touch and go, to be followed by another approach to a full stop. The radar vectors to final were somewhat shorter final approach segment than usual, and the handoff to the tower controller occurred on short final approach. My student attempted to contact tower, but received no communications from the tower controller. By this time we were very short final. Since there was no traffic waiting for takeoff and the runway was clear and we were well ahead of the aircraft approaching on the parallel runway 13L and had already planned to complete a touch and go landing and were concentrating on flying the aircraft, at this time we both apparently were assuming and inadvertently failed to obtain a clearance from the control tower. Perhaps the inserted radio frequency being incorrect or switching malfunction. The options were few due to being on short final situation. After the touch and go landing was completed and in the climb out, we switched back to the final controller. The final controller asked us if we contacted the tower. The answer was we initiated the call but received no answer. Shortly after this we experienced a generator light indicating a generator failure, so we terminated the IFR flight and returned to san antonio VFR conditions. Finally, there were no apparent hazards to us or any other aircraft. The problem was we failed to obtain a clearance from the tower, and not realizing this until after we had performed the touch and go landing.

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Original NASA ASRS Text

Title: GA SMA UNAUTH LNDG DURING A TRAINING FLT.

Narrative: PROB BEGAN WHEN CTLR ADVISED US OF A SINGLE-ENG MAKING AN APCH TO A PARALLEL RWY 13L. I INSTRUCTED MY STUDENT THAT I WOULD FIND THE TFC AND KEEP IT IN SIGHT SINCE MY STUDENT WAS FLYING THE ACFT AND HANDLING THE COMS. I WAS SOMEWHAT DISTRACTED BECAUSE OF THE OTHER ACFT, WHICH WE HAD IN SIGHT. OUR INITIAL COMS WITH RADAR CTLRS WERE THAT WE WOULD PERFORM ILS APCH TOUCH AND GO, TO BE FOLLOWED BY ANOTHER APCH TO A FULL STOP. THE RADAR VECTORS TO FINAL WERE SOMEWHAT SHORTER FINAL APCH SEGMENT THAN USUAL, AND THE HDOF TO THE TWR CTLR OCCURRED ON SHORT FINAL APCH. MY STUDENT ATTEMPTED TO CONTACT TWR, BUT RECEIVED NO COMS FROM THE TWR CTLR. BY THIS TIME WE WERE VERY SHORT FINAL. SINCE THERE WAS NO TFC WAITING FOR TKOF AND THE RWY WAS CLR AND WE WERE WELL AHEAD OF THE ACFT APCHING ON THE PARALLEL RWY 13L AND HAD ALREADY PLANNED TO COMPLETE A TOUCH AND GO LNDG AND WERE CONCENTRATING ON FLYING THE ACFT, AT THIS TIME WE BOTH APPARENTLY WERE ASSUMING AND INADVERTENTLY FAILED TO OBTAIN A CLRNC FROM THE CTL TWR. PERHAPS THE INSERTED RADIO FREQ BEING INCORRECT OR SWITCHING MALFUNCTION. THE OPTIONS WERE FEW DUE TO BEING ON SHORT FINAL SITUATION. AFTER THE TOUCH AND GO LNDG WAS COMPLETED AND IN THE CLBOUT, WE SWITCHED BACK TO THE FINAL CTLR. THE FINAL CTLR ASKED US IF WE CONTACTED THE TWR. THE ANSWER WAS WE INITIATED THE CALL BUT RECEIVED NO ANSWER. SHORTLY AFTER THIS WE EXPERIENCED A GENERATOR LIGHT INDICATING A GENERATOR FAILURE, SO WE TERMINATED THE IFR FLT AND RETURNED TO SAN ANTONIO VFR CONDITIONS. FINALLY, THERE WERE NO APPARENT HAZARDS TO US OR ANY OTHER ACFT. THE PROB WAS WE FAILED TO OBTAIN A CLRNC FROM THE TWR, AND NOT REALIZING THIS UNTIL AFTER WE HAD PERFORMED THE TOUCH AND GO LNDG.

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.