Aeronca departure from rvs took off without ATC clearance causing go around.

Attributes
ACN	606682
Time
Date	200401
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : rvs.airport
State Reference	OK
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : rvs.tower
Operator	general aviation : personal
Make Model Name	Cruisemaster
Operating Under FAR Part	Part 91
Flight Phase	climbout : takeoff ground : takeoff roll
Flight Plan	None
Aircraft 2
Controlling Facilities	tower : rvs.tower
Operator	general aviation : personal
Make Model Name	Cessna 150
Operating Under FAR Part	Part 91
Flight Phase	landing : go around
Person 1
Affiliation	other
Function	flight crew : captain oversight : pic
Qualification	pilot : private pilot : multi engine pilot : commercial pilot : instrument
Experience	flight time last 90 days : 76.4 flight time total : 5000 flight time type : 19.5
ASRS Report	606682
Person 2
Affiliation	other
Function	flight crew : single pilot
Events
Anomaly	conflict : airborne less severe non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : executed go around
Consequence	faa : reviewed incident with flight crew
Miss Distance	vertical : 150
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

At rvs airport, aeronca was asked by ground control to contact tower north side of runway 13. Upon switching to tower frequency 120.3 I heard 'aircraft Y cleared on course.' I responded 'aircraft Y cleared for takeoff,' and proceeded with the takeoff roll. No further response came from the tower until after I was airborne. After liftoff, I observed a small cessna passing overhead on the 'go around.' the cessna was approximately 150 ft above and in front of me. I was approximately 200 ft in the air when the tower informed me that I had not been cleared for takeoff. I responded that I thought I had been cleared. The tower acknowledged that my call sign had been used but that no clearance was given. When the tower said 'aircraft Y cleared on course,' I presumed they were in a hurry to get me off and I acknowledged and responded by commencing the takeoff. I believe the tower had intended the 'clearance on course' for another aircraft and inadvertently used my call sign with such clearance, resulting in confusion. I acknowledged the clearance as a takeoff clearance and got no corrective response from the tower. I fly big planes into big airports and it is not unusual for the tower to initiate the call after being switched by ground control to tower.

Original NASA ASRS Text

Title: AERONCA DEP FROM RVS TOOK OFF WITHOUT ATC CLRNC CAUSING GAR.

Narrative: AT RVS ARPT, AERONCA WAS ASKED BY GND CTL TO CONTACT TWR N SIDE OF RWY 13. UPON SWITCHING TO TWR FREQ 120.3 I HEARD 'ACFT Y CLRED ON COURSE.' I RESPONDED 'ACFT Y CLRED FOR TKOF,' AND PROCEEDED WITH THE TKOF ROLL. NO FURTHER RESPONSE CAME FROM THE TWR UNTIL AFTER I WAS AIRBORNE. AFTER LIFTOFF, I OBSERVED A SMALL CESSNA PASSING OVERHEAD ON THE 'GAR.' THE CESSNA WAS APPROX 150 FT ABOVE AND IN FRONT OF ME. I WAS APPROX 200 FT IN THE AIR WHEN THE TWR INFORMED ME THAT I HAD NOT BEEN CLRED FOR TKOF. I RESPONDED THAT I THOUGHT I HAD BEEN CLRED. THE TWR ACKNOWLEDGED THAT MY CALL SIGN HAD BEEN USED BUT THAT NO CLRNC WAS GIVEN. WHEN THE TWR SAID 'ACFT Y CLRED ON COURSE,' I PRESUMED THEY WERE IN A HURRY TO GET ME OFF AND I ACKNOWLEDGED AND RESPONDED BY COMMENCING THE TKOF. I BELIEVE THE TWR HAD INTENDED THE 'CLRNC ON COURSE' FOR ANOTHER ACFT AND INADVERTENTLY USED MY CALL SIGN WITH SUCH CLRNC, RESULTING IN CONFUSION. I ACKNOWLEDGED THE CLRNC AS A TKOF CLRNC AND GOT NO CORRECTIVE RESPONSE FROM THE TWR. I FLY BIG PLANES INTO BIG ARPTS AND IT IS NOT UNUSUAL FOR THE TWR TO INITIATE THE CALL AFTER BEING SWITCHED BY GND CTL TO TWR.

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.