Narrative:

On annual flight review with husband, also a pilot, in back seat. During the runup on the ground I for the first time switched the magnetos from both to right, back to both, then right, left and back to where the key was on both. RPM was find, engine sounded fine. Did a short (runway 36) field takeoff for the afr, switched frequencys to departure. At about 1000' MSL the engine was very noticeably rough. I did a 180 degree turn called departure and asked for clearance to land downwind runway 18. It was a difficult situation as visibility was very hazy (a bad 5 mi), we were low and if engine quit would not make it to runway, we were in the traffic area and talking to departure who was talking to the tower for us. Did not have time to check for cause of problem on switch radio frequencys as looking for aircraft and places to land. Landed and found that although key was on both mags according to the INS panel; in fact, it was on one set of magnetic and the time 'both' position was closer to where 'start' was indicated. We had a fouled spark plug. Had I checked the mags in the order I was taught, this could not have happened. Also, sometimes tower passes us to departure when we're a couple hundred ft in air. If have emergency and need to land climb out possible traffic conflict and delayed clearance because you're on the wrong frequency.

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Original NASA ASRS Text

Title: PVT PLT WITH INSTRUCTOR ENCOUNTERS ROUGH ENGINE DUE TO MAGNETO PROBLEM IMMEDIATELY AFTER TKOF FROM TLH. MAKES 180 DEGREE TURN TO LAND DOWNWIND WHILE COORD WITH DEP CTL SINCE THERE WAS NOT TIME TO SWITCH BACK TO TWR FREQ.

Narrative: ON ANNUAL FLT REVIEW WITH HUSBAND, ALSO A PLT, IN BACK SEAT. DURING THE RUNUP ON THE GND I FOR THE FIRST TIME SWITCHED THE MAGNETOS FROM BOTH TO RIGHT, BACK TO BOTH, THEN RIGHT, LEFT AND BACK TO WHERE THE KEY WAS ON BOTH. RPM WAS FIND, ENG SOUNDED FINE. DID A SHORT (RWY 36) FIELD TKOF FOR THE AFR, SWITCHED FREQS TO DEP. AT ABOUT 1000' MSL THE ENG WAS VERY NOTICEABLY ROUGH. I DID A 180 DEG TURN CALLED DEP AND ASKED FOR CLRNC TO LAND DOWNWIND RWY 18. IT WAS A DIFFICULT SITUATION AS VISIBILITY WAS VERY HAZY (A BAD 5 MI), WE WERE LOW AND IF ENG QUIT WOULD NOT MAKE IT TO RWY, WE WERE IN THE TFC AREA AND TALKING TO DEP WHO WAS TALKING TO THE TWR FOR US. DID NOT HAVE TIME TO CHK FOR CAUSE OF PROB ON SWITCH RADIO FREQS AS LOOKING FOR ACFT AND PLACES TO LAND. LANDED AND FOUND THAT ALTHOUGH KEY WAS ON BOTH MAGS ACCORDING TO THE INS PANEL; IN FACT, IT WAS ON ONE SET OF MAG AND THE TIME 'BOTH' POS WAS CLOSER TO WHERE 'START' WAS INDICATED. WE HAD A FOULED SPARK PLUG. HAD I CHKED THE MAGS IN THE ORDER I WAS TAUGHT, THIS COULD NOT HAVE HAPPENED. ALSO, SOMETIMES TWR PASSES US TO DEP WHEN WE'RE A COUPLE HUNDRED FT IN AIR. IF HAVE EMER AND NEED TO LAND CLBOUT POSSIBLE TFC CONFLICT AND DELAYED CLRNC BECAUSE YOU'RE ON THE WRONG FREQ.

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.