|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1201 To 1800|
|Locale Reference||atc facility : oak|
|Altitude||msl bound lower : 0|
msl bound upper : 2800
|Controlling Facilities||tower : oak|
|Operator||general aviation : instructional|
|Make Model Name||Small Aircraft, High Wing, 1 Eng, Fixed Gear|
|Flight Phase||cruise other|
|Route In Use||approach : visual|
|Function||instruction : instructor|
|Qualification||pilot : cfi|
pilot : atp
|Experience||flight time last 90 days : 120|
flight time total : 2200
flight time type : 800
|Function||instruction : trainee|
|Qualification||pilot : student|
|Anomaly||aircraft equipment problem : less severe|
|Independent Detector||other controllera|
other flight crewa
|Resolutory Action||flight crew : declared emergency|
none taken : unable
|Consequence||faa : reviewed incident with flight crew|
After a series of touch and goes, my student and I departed oak to the northeast. I had requested 'negative services beyond 5 mi,' since the oak arsa has no outer core in the northeast sector and I intended to do a brief bit of airwork 7 mi northeast, then return to oak. While climbing out we were advised of traffic in our 1 O'clock position. We (my student, actually) acknowledged the traffic. Approximately 5 mi northeast of oak our intercom ceased to function. Shortly thereafter I realized that our radio was inoperative (no reception). I attempted to contact the tower, then tried to receive several other known frequencys (local ATIS, etc). Realizing that we'd lost communication, but were clear of the arsa, I elected to change transponder codes from our discrete assigned code to 1200. While circling in the area at 2800' MSL we attempted to troubleshoot the problem. I changed frequencys, turned the radio off, checked the ammeter, checked my push-to-talk button, checked the hand-held microphone button and thought I observed my student manipulating his push-to-talk button. I did not check the circuit breaker's, as the radio frequency display still showed up and we could receive the navigation side of the navigation communication. We knew then that our cabin speaker and headsets were both functioning normally. My student and I then discussed radio failure procedures and a procedure for returning to oak. We set 7700 in the transponder for 1 min, then 7600. I transmitted in the blind to oak tower of our intentions, believing we might still have that capability. We then initiated a descent to enter right traffic runway 27R. I turned on all our lights: landing, strobes, navigation lights. Near the bottom of our descent, as we were about to enter downwind on a 45 degree entry, my student said, 'I smell smoke!' at that moment I too smelled electrical burning. I instructed my student to turn off the master switch and to close his fresh air vent. I took control of the airplane and checked all fresh air vents closed and closed the cabin heat as well. I flew the pattern, rocked my wings downwind, on base and on final. I saw a green light from the tower on final, landed (too fast, by the way), taxied and shut down. I then telephoned the tower. Tower personnel said we had a stuck microphone. I realized at that point that I had not myself checked my student's push-to-talk button nor had I instructed him to check it. However, when we rechked it afterwards it was not stuck, perhaps from my ungraceful landing. Several pts: I didn't check all the microphone buttons, I didn't check the circuit breaker's, I didn't turn all switches off when we smelled electrical burning (only the master), I landed poorly--too much in a hurry to get on the ground--believing we were about to have a fire, ATC green lights are almost invisible in bright daylight--my student never saw it, and we had no fire extinguisher onboard. I will from now on be teaching my students about stuck microphone possibilities and making sure they know emergency procedures thoroughly.
Original NASA ASRS Text
Title: GA-SMA HAD STUCK MIC AND WAS UNABLE TO COMMUNICATE WITH OAK TWR FOR COORD RETURN.
Narrative: AFTER A SERIES OF TOUCH AND GOES, MY STUDENT AND I DEPARTED OAK TO THE NE. I HAD REQUESTED 'NEGATIVE SVCS BEYOND 5 MI,' SINCE THE OAK ARSA HAS NO OUTER CORE IN THE NE SECTOR AND I INTENDED TO DO A BRIEF BIT OF AIRWORK 7 MI NE, THEN RETURN TO OAK. WHILE CLBING OUT WE WERE ADVISED OF TFC IN OUR 1 O'CLOCK POS. WE (MY STUDENT, ACTUALLY) ACKNOWLEDGED THE TFC. APPROX 5 MI NE OF OAK OUR INTERCOM CEASED TO FUNCTION. SHORTLY THEREAFTER I REALIZED THAT OUR RADIO WAS INOP (NO RECEPTION). I ATTEMPTED TO CONTACT THE TWR, THEN TRIED TO RECEIVE SEVERAL OTHER KNOWN FREQS (LCL ATIS, ETC). REALIZING THAT WE'D LOST COM, BUT WERE CLR OF THE ARSA, I ELECTED TO CHANGE TRANSPONDER CODES FROM OUR DISCRETE ASSIGNED CODE TO 1200. WHILE CIRCLING IN THE AREA AT 2800' MSL WE ATTEMPTED TO TROUBLESHOOT THE PROB. I CHANGED FREQS, TURNED THE RADIO OFF, CHKED THE AMMETER, CHKED MY PUSH-TO-TALK BUTTON, CHKED THE HAND-HELD MIC BUTTON AND THOUGHT I OBSERVED MY STUDENT MANIPULATING HIS PUSH-TO-TALK BUTTON. I DID NOT CHK THE CB'S, AS THE RADIO FREQ DISPLAY STILL SHOWED UP AND WE COULD RECEIVE THE NAV SIDE OF THE NAV COM. WE KNEW THEN THAT OUR CABIN SPEAKER AND HEADSETS WERE BOTH FUNCTIONING NORMALLY. MY STUDENT AND I THEN DISCUSSED RADIO FAILURE PROCS AND A PROC FOR RETURNING TO OAK. WE SET 7700 IN THE TRANSPONDER FOR 1 MIN, THEN 7600. I TRANSMITTED IN THE BLIND TO OAK TWR OF OUR INTENTIONS, BELIEVING WE MIGHT STILL HAVE THAT CAPABILITY. WE THEN INITIATED A DSCNT TO ENTER RIGHT TFC RWY 27R. I TURNED ON ALL OUR LIGHTS: LNDG, STROBES, NAV LIGHTS. NEAR THE BOTTOM OF OUR DSCNT, AS WE WERE ABOUT TO ENTER DOWNWIND ON A 45 DEG ENTRY, MY STUDENT SAID, 'I SMELL SMOKE!' AT THAT MOMENT I TOO SMELLED ELECTRICAL BURNING. I INSTRUCTED MY STUDENT TO TURN OFF THE MASTER SWITCH AND TO CLOSE HIS FRESH AIR VENT. I TOOK CTL OF THE AIRPLANE AND CHKED ALL FRESH AIR VENTS CLOSED AND CLOSED THE CABIN HEAT AS WELL. I FLEW THE PATTERN, ROCKED MY WINGS DOWNWIND, ON BASE AND ON FINAL. I SAW A GREEN LIGHT FROM THE TWR ON FINAL, LANDED (TOO FAST, BY THE WAY), TAXIED AND SHUT DOWN. I THEN TELEPHONED THE TWR. TWR PERSONNEL SAID WE HAD A STUCK MIC. I REALIZED AT THAT POINT THAT I HAD NOT MYSELF CHKED MY STUDENT'S PUSH-TO-TALK BUTTON NOR HAD I INSTRUCTED HIM TO CHK IT. HOWEVER, WHEN WE RECHKED IT AFTERWARDS IT WAS NOT STUCK, PERHAPS FROM MY UNGRACEFUL LNDG. SEVERAL PTS: I DIDN'T CHK ALL THE MIC BUTTONS, I DIDN'T CHK THE CB'S, I DIDN'T TURN ALL SWITCHES OFF WHEN WE SMELLED ELECTRICAL BURNING (ONLY THE MASTER), I LANDED POORLY--TOO MUCH IN A HURRY TO GET ON THE GND--BELIEVING WE WERE ABOUT TO HAVE A FIRE, ATC GREEN LIGHTS ARE ALMOST INVISIBLE IN BRIGHT DAYLIGHT--MY STUDENT NEVER SAW IT, AND WE HAD NO FIRE EXTINGUISHER ONBOARD. I WILL FROM NOW ON BE TEACHING MY STUDENTS ABOUT STUCK MIC POSSIBILITIES AND MAKING SURE THEY KNOW EMER PROCS THOROUGHLY.
Data retrieved from NASA's ASRS site as of August 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.