Narrative:

After obtaining ATIS and contacting clearance delivery, contacted ground to taxi to active. Followed a falcon jet out of parking area to what I thought was runway 31R. I had stopped at what I thought was runway 31R hold line as the falcon proceeded to runway 31L. I contacted tower. They asked my location, I told them 'behind the falcon jet, holding at runway 31R.' tower then cleared me for takeoff (at least I thought so) and said to be aware of wake turbulence from a departing learjet. I acknowledged and began takeoff roll and then was handed off to psp departure frequency, with the note that for future reference, 'please be aware that you had taken off from the taxiway.' needless to say, I was shocked -- not only did no one ever tell me of this beforehand, I was never told to abort, stop, or otherwise cease takeoff. The taxiway was sufficiently wide and long enough (approximately 8500 ft) to effect a safe takeoff, but my actions were in error. I believe there should be signage in the transient parking of FBO to note directions to runways 31L/right (also runways 13L/right) for aircraft not familiar with the airport. Neither runways 31L/right nor runways 13L/right start at the same point. Also, signs should be erected to warn that 'this is a taxiway, not a runway' at each end of the taxiway which is between each runway. Essentially, this was a confused situation. I did note afterward that there is a caution note in the pilot's guide to california airports, to not mistake taxiway C for runway 31L/31R. This leads me to believe that this is a situation that has come up before and has confused other pilots. I, myself, had missed the caution note. I also note that ground control (or tower control) should be more mindful of where every aircraft is on the airport. Their view should be unobstructed and they should alert pilots of mistakes/errors.

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Original NASA ASRS Text

Title: C172 PLT MAKES TKOF FROM TXWY. THOUGHT HE WAS ON THE RWY. ATC NOTIFIES HIM AFTER HE IS AIRBORNE. THERE IS A NOTICE ON A CHART TO NOT MISTAKE TXWY C FOR RWY.

Narrative: AFTER OBTAINING ATIS AND CONTACTING CLRNC DELIVERY, CONTACTED GND TO TAXI TO ACTIVE. FOLLOWED A FALCON JET OUT OF PARKING AREA TO WHAT I THOUGHT WAS RWY 31R. I HAD STOPPED AT WHAT I THOUGHT WAS RWY 31R HOLD LINE AS THE FALCON PROCEEDED TO RWY 31L. I CONTACTED TWR. THEY ASKED MY LOCATION, I TOLD THEM 'BEHIND THE FALCON JET, HOLDING AT RWY 31R.' TWR THEN CLRED ME FOR TKOF (AT LEAST I THOUGHT SO) AND SAID TO BE AWARE OF WAKE TURB FROM A DEPARTING LEARJET. I ACKNOWLEDGED AND BEGAN TKOF ROLL AND THEN WAS HANDED OFF TO PSP DEP FREQ, WITH THE NOTE THAT FOR FUTURE REF, 'PLEASE BE AWARE THAT YOU HAD TAKEN OFF FROM THE TXWY.' NEEDLESS TO SAY, I WAS SHOCKED -- NOT ONLY DID NO ONE EVER TELL ME OF THIS BEFOREHAND, I WAS NEVER TOLD TO ABORT, STOP, OR OTHERWISE CEASE TKOF. THE TXWY WAS SUFFICIENTLY WIDE AND LONG ENOUGH (APPROX 8500 FT) TO EFFECT A SAFE TKOF, BUT MY ACTIONS WERE IN ERROR. I BELIEVE THERE SHOULD BE SIGNAGE IN THE TRANSIENT PARKING OF FBO TO NOTE DIRECTIONS TO RWYS 31L/R (ALSO RWYS 13L/R) FOR ACFT NOT FAMILIAR WITH THE ARPT. NEITHER RWYS 31L/R NOR RWYS 13L/R START AT THE SAME POINT. ALSO, SIGNS SHOULD BE ERECTED TO WARN THAT 'THIS IS A TXWY, NOT A RWY' AT EACH END OF THE TXWY WHICH IS BTWN EACH RWY. ESSENTIALLY, THIS WAS A CONFUSED SIT. I DID NOTE AFTERWARD THAT THERE IS A CAUTION NOTE IN THE PLT'S GUIDE TO CALIFORNIA ARPTS, TO NOT MISTAKE TXWY C FOR RWY 31L/31R. THIS LEADS ME TO BELIEVE THAT THIS IS A SIT THAT HAS COME UP BEFORE AND HAS CONFUSED OTHER PLTS. I, MYSELF, HAD MISSED THE CAUTION NOTE. I ALSO NOTE THAT GND CTL (OR TWR CTL) SHOULD BE MORE MINDFUL OF WHERE EVERY ACFT IS ON THE ARPT. THEIR VIEW SHOULD BE UNOBSTRUCTED AND THEY SHOULD ALERT PLTS OF MISTAKES/ERRORS.

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.