Training flight with student and instructor taxied back on runway for takeoff, heard the word 'takeo...

Attributes
ACN	178416
Time
Date	199105
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : hou
State Reference	TX
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : instructional
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	climbout : takeoff
Flight Plan	None
Person 1
Affiliation	Other
Function	instruction : instructor
Qualification	pilot : instrument pilot : commercial pilot : cfi
Experience	flight time last 90 days : 60 flight time total : 988 flight time type : 50
ASRS Report	178416
Person 2
Affiliation	Other
Function	flight crew : single pilot instruction : trainee
Qualification	pilot : student
Events
Anomaly	incursion : runway non adherence : clearance non adherence : far
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While on a student pilot training flight into the primary airport of an arsa, and after landing, my student taxied clear of the runway. Tower asked our intentions. My student requested to taxi to takeoff. Tower directed us to back-taxi on runway 12L, hold in position and advise tower when we were ready to go. My student advised tower that we were ready. Immediately we heard the words, 'take off.' we took off west/O conflict with any other traffic. After liftoff tower informed us that we had not been cleared for takeoff. Tower requested that we give them a call on the phone when we returned to our base. I called tower and again was informed that we had taken off west/O clearance to do so. The problem arose from the hurried nature of operations at this busy airport. The problem might have been avoided if we had been directed to taxi back via txwys. This would have allowed us time to plan and prepare for takeoff. What was intended to be an educational flight left my student a little confused and intimidated. I realize that I should have informed ATC that this was a student training flight and I should have made my student verify that the words 'take off' were intended for us.

Original NASA ASRS Text

Title: TRAINING FLT WITH STUDENT AND INSTRUCTOR TAXIED BACK ON RWY FOR TKOF, HEARD THE WORD 'TKOF,' SO PROCEEDED TO DO SO. CLRNC APPARENTLY MISUNDERSTOOD. TWR ADVISED THEY HAD TAKEN OFF WITHOUT CLRNC.

Narrative: WHILE ON A STUDENT PLT TRNING FLT INTO THE PRIMARY ARPT OF AN ARSA, AND AFTER LNDG, MY STUDENT TAXIED CLR OF THE RWY. TWR ASKED OUR INTENTIONS. MY STUDENT REQUESTED TO TAXI TO TKOF. TWR DIRECTED US TO BACK-TAXI ON RWY 12L, HOLD IN POS AND ADVISE TWR WHEN WE WERE READY TO GO. MY STUDENT ADVISED TWR THAT WE WERE READY. IMMEDIATELY WE HEARD THE WORDS, 'TAKE OFF.' WE TOOK OFF W/O CONFLICT WITH ANY OTHER TFC. AFTER LIFTOFF TWR INFORMED US THAT WE HAD NOT BEEN CLRED FOR TKOF. TWR REQUESTED THAT WE GIVE THEM A CALL ON THE PHONE WHEN WE RETURNED TO OUR BASE. I CALLED TWR AND AGAIN WAS INFORMED THAT WE HAD TAKEN OFF W/O CLRNC TO DO SO. THE PROB AROSE FROM THE HURRIED NATURE OF OPS AT THIS BUSY ARPT. THE PROB MIGHT HAVE BEEN AVOIDED IF WE HAD BEEN DIRECTED TO TAXI BACK VIA TXWYS. THIS WOULD HAVE ALLOWED US TIME TO PLAN AND PREPARE FOR TKOF. WHAT WAS INTENDED TO BE AN EDUCATIONAL FLT LEFT MY STUDENT A LITTLE CONFUSED AND INTIMIDATED. I REALIZE THAT I SHOULD HAVE INFORMED ATC THAT THIS WAS A STUDENT TRNING FLT AND I SHOULD HAVE MADE MY STUDENT VERIFY THAT THE WORDS 'TAKE OFF' WERE INTENDED FOR US.

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.

Training flight with student and instructor taxied back on runway for takeoff, heard the word 'takeoff,' so proceeded to do so. Clearance apparently misunderstood. Tower advised they had taken off without clearance.