Narrative:

Towards dusk I was shooting touch and goes at lunken field. Active runways were 2L and 2R. I was using 2L. The WX was better than 5000' and 5 mi with a light northerly wind. The traffic was very light to none. During the previous circuits I had been cleared for landing roughly abeam the numbers on the downwind leg. I have had radio problems in the past with this airplane, which exhibited themselves in the radios suddenly going dead. Both radios were fixed almost a yr ago, but the #2 radio had started to show the same symptoms again on a recent trip to fl. I have never had a stuck microphone before. I was using a type a intercom with type a ptt switches. This particular evening I was practicing power off approachs, so I was concentrating on my airspeed and my distance from the runway. I did not receive my clearance abeam the numbers on this circuit, but I knew from previous experience that I could receive it as late as on final. I have flown almost 300 hours in the last yr, with lunken as my home airport, so I felt that I knew the procedures pretty well. Due to my concentration on the power off approach I did not attempt to call the tower until I was on very short final. I looked at the tower and realized that they were flashing a red light at me. I climbed out, rocking my wings as I did so. I continued to fly a standard pattern while watching the tower for further light signals and rocking my wings in acknowledgement. Throughout my crosswind and downwind the tower continued to flash a red light at me. On downwind I tried switching radios, and frequencys, and also turned the audio panel to speaker. This had no effect, and I thought that my radios had just gone dead. I tried to click the ptt a couple of times and it felt ok but evidently it was not releasing all the way. On downwind abeam the numbers the tower was still flashing a red light at me, so I climbed to 2000' MSL, which is 200' above the traffic pattern. As I reached the departure end of runway 2R the tower flashed a green light at me, so I rocked my wings in acknowledgement and started a descent while turning crosswind. I got the light signal and taxied back to the ramp. I believe that the problem was caused by several factors. The similarity between the radio problems I have had in the past and the symptoms of a stuck microphone. My concentration on flying a power off pattern caused me to notice a problem later then I would otherwise have done, however it made no difference to the problem resolution once it was discovered. The lack of an indicator on my intercom or radio which showed that the radio was transmitting. The extremely poor quality of the ptt (even though it cost the usurious sum of $15). The same light signals used for radios out and for stuck microphone. If the tower had been able to give me a light signal for stuck microphone I would have immediately checked that or unplugged the intercom and used my hand-held microphone and speaker.

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Original NASA ASRS Text

Title: GA SMA WAS FLYING IN LUK ATA WITH A STUCK MIC.

Narrative: TOWARDS DUSK I WAS SHOOTING TOUCH AND GOES AT LUNKEN FIELD. ACTIVE RWYS WERE 2L AND 2R. I WAS USING 2L. THE WX WAS BETTER THAN 5000' AND 5 MI WITH A LIGHT NORTHERLY WIND. THE TFC WAS VERY LIGHT TO NONE. DURING THE PREVIOUS CIRCUITS I HAD BEEN CLRED FOR LNDG ROUGHLY ABEAM THE NUMBERS ON THE DOWNWIND LEG. I HAVE HAD RADIO PROBS IN THE PAST WITH THIS AIRPLANE, WHICH EXHIBITED THEMSELVES IN THE RADIOS SUDDENLY GOING DEAD. BOTH RADIOS WERE FIXED ALMOST A YR AGO, BUT THE #2 RADIO HAD STARTED TO SHOW THE SAME SYMPTOMS AGAIN ON A RECENT TRIP TO FL. I HAVE NEVER HAD A STUCK MIC BEFORE. I WAS USING A TYPE A INTERCOM WITH TYPE A PTT SWITCHES. THIS PARTICULAR EVENING I WAS PRACTICING PWR OFF APCHS, SO I WAS CONCENTRATING ON MY AIRSPD AND MY DISTANCE FROM THE RWY. I DID NOT RECEIVE MY CLRNC ABEAM THE NUMBERS ON THIS CIRCUIT, BUT I KNEW FROM PREVIOUS EXPERIENCE THAT I COULD RECEIVE IT AS LATE AS ON FINAL. I HAVE FLOWN ALMOST 300 HRS IN THE LAST YR, WITH LUNKEN AS MY HOME ARPT, SO I FELT THAT I KNEW THE PROCS PRETTY WELL. DUE TO MY CONCENTRATION ON THE PWR OFF APCH I DID NOT ATTEMPT TO CALL THE TWR UNTIL I WAS ON VERY SHORT FINAL. I LOOKED AT THE TWR AND REALIZED THAT THEY WERE FLASHING A RED LIGHT AT ME. I CLBED OUT, ROCKING MY WINGS AS I DID SO. I CONTINUED TO FLY A STANDARD PATTERN WHILE WATCHING THE TWR FOR FURTHER LIGHT SIGNALS AND ROCKING MY WINGS IN ACKNOWLEDGEMENT. THROUGHOUT MY XWIND AND DOWNWIND THE TWR CONTINUED TO FLASH A RED LIGHT AT ME. ON DOWNWIND I TRIED SWITCHING RADIOS, AND FREQS, AND ALSO TURNED THE AUDIO PANEL TO SPEAKER. THIS HAD NO EFFECT, AND I THOUGHT THAT MY RADIOS HAD JUST GONE DEAD. I TRIED TO CLICK THE PTT A COUPLE OF TIMES AND IT FELT OK BUT EVIDENTLY IT WAS NOT RELEASING ALL THE WAY. ON DOWNWIND ABEAM THE NUMBERS THE TWR WAS STILL FLASHING A RED LIGHT AT ME, SO I CLBED TO 2000' MSL, WHICH IS 200' ABOVE THE TFC PATTERN. AS I REACHED THE DEP END OF RWY 2R THE TWR FLASHED A GREEN LIGHT AT ME, SO I ROCKED MY WINGS IN ACKNOWLEDGEMENT AND STARTED A DSNT WHILE TURNING XWIND. I GOT THE LIGHT SIGNAL AND TAXIED BACK TO THE RAMP. I BELIEVE THAT THE PROB WAS CAUSED BY SEVERAL FACTORS. THE SIMILARITY BTWN THE RADIO PROBS I HAVE HAD IN THE PAST AND THE SYMPTOMS OF A STUCK MIC. MY CONCENTRATION ON FLYING A PWR OFF PATTERN CAUSED ME TO NOTICE A PROBLEM LATER THEN I WOULD OTHERWISE HAVE DONE, HOWEVER IT MADE NO DIFFERENCE TO THE PROB RESOLUTION ONCE IT WAS DISCOVERED. THE LACK OF AN INDICATOR ON MY INTERCOM OR RADIO WHICH SHOWED THAT THE RADIO WAS XMITTING. THE EXTREMELY POOR QUALITY OF THE PTT (EVEN THOUGH IT COST THE USURIOUS SUM OF $15). THE SAME LIGHT SIGNALS USED FOR RADIOS OUT AND FOR STUCK MIC. IF THE TWR HAD BEEN ABLE TO GIVE ME A LIGHT SIGNAL FOR STUCK MIC I WOULD HAVE IMMEDIATELY CHKED THAT OR UNPLUGGED THE INTERCOM AND USED MY HAND-HELD MIC AND SPEAKER.

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.