Narrative:

As my student practiced short-field lndgs at palo alto, while I was instructing, the following event occurred: student was high on approach path but low on airspeed so I instructed him to reduce power and lower the nose. He reduced power, but did not lower nose enough to gain enough airspeed. However, we were still near recommended short field approach speed. As we got closer to the runway he got slower so I reached to apply power, but as I reached he suddenly yanked back on the yoke causing the aircraft to, in fact, stall in. We were probably at 2-4 ft off the ground as this occurred. I am still not sure if we made the end of the runway, or if the mains clipped the grass just prior to the runway. The whole event happened with such rapidity and in such an unexpected manner I was unable to correct the situation soon enough. I think that in future I will take the following steps to try to prevent this situation occurring again: 1) demonstrate procedure more than once prior to letting student try it by him/herself. 2) keep my hands right on controls for first couple of student attempts. 3) try to be even quicker with reactions. Unfortunately, I believe that in this particular situation, even if I was fully expecting the event it would have been almost impossible to correct the situation, as it happened so quickly and so close to the ground. There was no damage to the aircraft or occupants, and I was unable to ascertain anything more by inspection of the approach end of the runway.

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Original NASA ASRS Text

Title: LNDG UNDERSHOT WHILE PRACTICING SHORT FIELD LNDGS. TRAINING IN PROGRESS.

Narrative: AS MY STUDENT PRACTICED SHORT-FIELD LNDGS AT PALO ALTO, WHILE I WAS INSTRUCTING, THE FOLLOWING EVENT OCCURRED: STUDENT WAS HIGH ON APCH PATH BUT LOW ON AIRSPD SO I INSTRUCTED HIM TO REDUCE PWR AND LOWER THE NOSE. HE REDUCED PWR, BUT DID NOT LOWER NOSE ENOUGH TO GAIN ENOUGH AIRSPD. HOWEVER, WE WERE STILL NEAR RECOMMENDED SHORT FIELD APCH SPD. AS WE GOT CLOSER TO THE RWY HE GOT SLOWER SO I REACHED TO APPLY PWR, BUT AS I REACHED HE SUDDENLY YANKED BACK ON THE YOKE CAUSING THE ACFT TO, IN FACT, STALL IN. WE WERE PROBABLY AT 2-4 FT OFF THE GND AS THIS OCCURRED. I AM STILL NOT SURE IF WE MADE THE END OF THE RWY, OR IF THE MAINS CLIPPED THE GRASS JUST PRIOR TO THE RWY. THE WHOLE EVENT HAPPENED WITH SUCH RAPIDITY AND IN SUCH AN UNEXPECTED MANNER I WAS UNABLE TO CORRECT THE SIT SOON ENOUGH. I THINK THAT IN FUTURE I WILL TAKE THE FOLLOWING STEPS TO TRY TO PREVENT THIS SIT OCCURRING AGAIN: 1) DEMONSTRATE PROC MORE THAN ONCE PRIOR TO LETTING STUDENT TRY IT BY HIM/HERSELF. 2) KEEP MY HANDS RIGHT ON CTLS FOR FIRST COUPLE OF STUDENT ATTEMPTS. 3) TRY TO BE EVEN QUICKER WITH REACTIONS. UNFORTUNATELY, I BELIEVE THAT IN THIS PARTICULAR SIT, EVEN IF I WAS FULLY EXPECTING THE EVENT IT WOULD HAVE BEEN ALMOST IMPOSSIBLE TO CORRECT THE SIT, AS IT HAPPENED SO QUICKLY AND SO CLOSE TO THE GND. THERE WAS NO DAMAGE TO THE ACFT OR OCCUPANTS, AND I WAS UNABLE TO ASCERTAIN ANYTHING MORE BY INSPECTION OF THE APCH END OF THE RWY.

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.