Pilot of a C182 inadvertently took off on taxiway at tmb airport with multiple runway txwys.

Attributes
ACN	471213
Time
Date	200004
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : tmb.airport
State Reference	FL
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : tmb.tower
Operator	general aviation : personal
Make Model Name	Skylane 182/RG Turbo Skylane/RG
Operating Under FAR Part	Part 91
Flight Phase	climbout : takeoff
Flight Plan	None
Person 1
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Experience	controller limited radar : 3 controller military : 3 controller time certified in position1 : 2 flight time total : 100
ASRS Report	741213
Person 2
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : private
Events
Anomaly	incursion : taxiway non adherence : clearance non adherence other
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact none taken : insufficient time
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

A C182 was taxiing on a heading of 130 degrees on taxiway D, parallel to runway 31. Pilot called requesting departure clearance. I cleared him for takeoff runway 31, then turned my head to scan my d-brite scope. When I looked back, the C182 had crossed runway 31 and was rotating to depart on a 270 degree heading off taxiway east. Taxiway east crosses the end of runway 31 on an east/west heading. The C182 apparently had made the right turn off taxiway D onto runway 31, but didn't turn far enough to line up with the centerline and instead departed from the taxiway. There were no other aircraft in the airspace, and no aircraft on the ground were a factor. Fearing the pilot would be unable to abort the takeoff in the remaining distance of taxiway east, I said nothing and let him take off. Once the C182 was several hundred ft in the air, I asked the pilot if he was aware of what he had done. The pilot apologized and expressed embarrassment.

Original NASA ASRS Text

Title: PLT OF A C182 INADVERTENTLY TOOK OFF ON TXWY AT TMB ARPT WITH MULTIPLE RWY TXWYS.

Narrative: A C182 WAS TAXIING ON A HDG OF 130 DEGS ON TXWY D, PARALLEL TO RWY 31. PLT CALLED REQUESTING DEP CLRNC. I CLRED HIM FOR TKOF RWY 31, THEN TURNED MY HEAD TO SCAN MY D-BRITE SCOPE. WHEN I LOOKED BACK, THE C182 HAD CROSSED RWY 31 AND WAS ROTATING TO DEPART ON A 270 DEG HDG OFF TXWY E. TXWY E CROSSES THE END OF RWY 31 ON AN E/W HDG. THE C182 APPARENTLY HAD MADE THE R TURN OFF TXWY D ONTO RWY 31, BUT DIDN'T TURN FAR ENOUGH TO LINE UP WITH THE CTRLINE AND INSTEAD DEPARTED FROM THE TXWY. THERE WERE NO OTHER ACFT IN THE AIRSPACE, AND NO ACFT ON THE GND WERE A FACTOR. FEARING THE PLT WOULD BE UNABLE TO ABORT THE TKOF IN THE REMAINING DISTANCE OF TXWY E, I SAID NOTHING AND LET HIM TAKE OFF. ONCE THE C182 WAS SEVERAL HUNDRED FT IN THE AIR, I ASKED THE PLT IF HE WAS AWARE OF WHAT HE HAD DONE. THE PLT APOLOGIZED AND EXPRESSED EMBARRASSMENT.

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.