Pilot commenced takeoff roll with position and hold clearance.

Attributes
ACN	312120
Time
Date	199508
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : rnt
State Reference	WA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Experimental
Operating Under FAR Part	Part 91
Flight Phase	climbout : takeoff
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Experience	flight time last 90 days : 7 flight time total : 3700 flight time type : 20
ASRS Report	312120
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	non adherence : clearance other anomaly other
Independent Detector	other controllera other flight crewa other other : unspecified cockpit
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

2ND flight this yr in the aircraft. Going out to maintain tailwheel currency and light aerobatics. Cleared into position and hold. While holding on runway became preoccupied with watching departing traffic, which was alternating between pitching up, and down, on departure. Eventually that traffic stabilized in a climb, and turned crosswind. With the prior departure out of the way I started my takeoff, forgetting that I had only been cleared into position and hold, not to takeoff when traffic was clear. Very accommodating controller. He cleared me for takeoff while I was on the roll. Primary cause: lack of currency, causing me to be preoccupied with aircraft control on takeoff, as opposed to really paying attention to tower clrncs.

Original NASA ASRS Text

Title: PLT COMMENCED TKOF ROLL WITH POS AND HOLD CLRNC.

Narrative: 2ND FLT THIS YR IN THE ACFT. GOING OUT TO MAINTAIN TAILWHEEL CURRENCY AND LIGHT AEROBATICS. CLRED INTO POS AND HOLD. WHILE HOLDING ON RWY BECAME PREOCCUPIED WITH WATCHING DEPARTING TFC, WHICH WAS ALTERNATING BTWN PITCHING UP, AND DOWN, ON DEP. EVENTUALLY THAT TFC STABILIZED IN A CLB, AND TURNED XWIND. WITH THE PRIOR DEP OUT OF THE WAY I STARTED MY TKOF, FORGETTING THAT I HAD ONLY BEEN CLRED INTO POS AND HOLD, NOT TO TKOF WHEN TFC WAS CLR. VERY ACCOMMODATING CTLR. HE CLRED ME FOR TKOF WHILE I WAS ON THE ROLL. PRIMARY CAUSE: LACK OF CURRENCY, CAUSING ME TO BE PREOCCUPIED WITH ACFT CTL ON TKOF, AS OPPOSED TO REALLY PAYING ATTN TO TWR CLRNCS.

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.