Flight instructor reports his student became inadvertently airborne while doing fast taxi maneuvers ...

Narrative:

I was conducting nose-high; fast-taxi maneuvers to illustrate the landing attitude to my student. To accomplish this; we had conducted three passes down runway 12R/30L; turning 180 degrees at the ends; with tower clearance. I had informed tower that we may become momentarily airborne. After the third pass; we repositioned to runway 30R as instructed; for a final fast-taxi pass; our intent was to then depart runway 12L in left closed traffic for pattern work. I transferred control to my student; and asked that the she repeat the maneuver. She used sufficient power to become airborne; and I noted that she did not immediately retard the throttle; and we were climbing slowly. I took control at a moment when I could not see the 12L end of the runway. By the time I yawed the aircraft to give me sufficient visibility; I determined that continuing in a normal climb would be safer than attempting to land on the remaining runway. As we climbed out; tower commented 'that was not the fast taxi we expected.' I apologized and stated that I did not believe we could have stopped safely in the runway remaining. I noted tower instructing another aircraft to hold position; and attempted unsuccessfully to observe his position on the ground. Upon landing; ground control informed me of a possible pilot deviation and asked me to call the tower. When I called; tower explained that the other aircraft had already been issued a takeoff clearance. I do not know whether that aircraft had already begun moving; but it was clearly a potentially dangerous situation. Lessons for me include noting how quickly a student can convert a fast-taxi into a fully-developed takeoff and climb; and to be ready to assume control more quickly in that situation. Further; I believe that it would be better to request a takeoff clearance from tower; and notify them that we may simply fast-taxi the length of the runway and exit at the far end; to cover the possibility of the fast-taxi becoming a departure.

Original NASA ASRS Text

Title: Flight Instructor reports his student became inadvertently airborne while doing fast taxi maneuvers to illustrate the landing attitude. The instructor elected to continue the takeoff as stopping seemed risky; resulting in the Tower canceling the takeoff clearance of another aircraft.

Narrative: I was conducting nose-high; fast-taxi maneuvers to illustrate the landing attitude to my student. To accomplish this; we had conducted three passes down Runway 12R/30L; turning 180 degrees at the ends; with Tower clearance. I had informed Tower that we may become momentarily airborne. After the third pass; we repositioned to Runway 30R as instructed; for a final fast-taxi pass; our intent was to then depart Runway 12L in left closed traffic for pattern work. I transferred control to my student; and asked that the she repeat the maneuver. She used sufficient power to become airborne; and I noted that she did not immediately retard the throttle; and we were climbing slowly. I took control at a moment when I could not see the 12L end of the runway. By the time I yawed the aircraft to give me sufficient visibility; I determined that continuing in a normal climb would be safer than attempting to land on the remaining runway. As we climbed out; Tower commented 'That was not the fast taxi we expected.' I apologized and stated that I did not believe we could have stopped safely in the runway remaining. I noted Tower instructing another aircraft to hold position; and attempted unsuccessfully to observe his position on the ground. Upon landing; Ground Control informed me of a possible pilot deviation and asked me to call the Tower. When I called; Tower explained that the other aircraft had already been issued a takeoff clearance. I do not know whether that aircraft had already begun moving; but it was clearly a potentially dangerous situation. Lessons for me include noting how quickly a student can convert a fast-taxi into a fully-developed takeoff and climb; and to be ready to assume control more quickly in that situation. Further; I believe that it would be better to request a takeoff clearance from Tower; and notify them that we may simply fast-taxi the length of the runway and exit at the far end; to cover the possibility of the fast-taxi becoming a departure.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	849449
Time
Date	200908
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Cessna 152
Operating Under FAR Part	Part 91
Flight Phase	Takeoff
Route In Use	None
Flight Plan	None
Person 1
Function	Instructor Pilot Not Flying
Qualification	Flight Crew Commercial Flight Crew Flight Instructor Flight Crew Instrument
Experience	Flight Crew Last 90 Days 164 Flight Crew Total 5416 Flight Crew Type 200
Events
Anomaly	Conflict Ground Conflict Less Severe Deviation - Procedural Clearance

Flight instructor reports his student became inadvertently airborne while doing fast taxi maneuvers to illustrate the landing attitude. The instructor elected to continue the takeoff as stopping seemed risky; resulting in the tower canceling the takeoff clearance of another aircraft.