Narrative:

As a tow pilot for a gliderport; I was preparing for the 8TH launch of a fairly busy afternoon. The tow rope (about 200 ft) normally remained attached to the tow plane through all phases of the operation. For efficiency; I had taxied the tow plane to position the glider's end of the tow rope within easy reach for hook-up to the glider. I then taxied forward; lining up in front of the glider and positioning the tow plane far enough away to minimize the propeller wash blowing the 2 men who would be in the glider. It appeared that the 'ride pilot' was assisting the customer getting settled into the front seat. I left a significant amount of slack in the rope to allow for glider hook-up and/or to preclude moving the glider forward before they were in and ready. I then occupied myself with the pretkof checklist. A few mins later I saw in the tow plane's mirror that the glider's canopy was closing and the wing was being raised by the 'wing runner.' the wing runner was a boy looking to be 8-10 yrs old. He acted uncertain; confirming to me that I would rely on signals from the glider; not just him. The rudder on the glider fanned a few times and the boy confirmed with the circular wave 'launch' signal. I quickly scanned the pattern and runway for conflicts and responded by fanning the tow plane rudder. This confirmed that I was about to take off. I applied full power and checked the engine gauges. As the tow plane accelerated; I glanced at the glider in the mirror. Instead of seeing the glider's start; I saw the rope quickly moving as the remaining slack was taken up. I immediately pulled the throttle back and applied the brakes heavily. The nose pitched downward and the propeller cut into the grass runway. The engine stopped in about 10-15 revolutions. In the next few moments; the tail came back down with a thud. No one was hurt. I was uninjured. I turned off the aircraft's electrical switches; magnetos and shut off the fuel. I got out; glanced at the damage; and walked back to check the people in the glider. They and the boy were physically unaffected. Since the tow plane stopped before the rope's slack was entirely taken up; the glider never moved. Damage to the tow plane: to the naked eye; the propeller was worn and 1 blade was bent. Engine damage is unknown at the time of this writing. 2 leaves of the tailwheel springs broke. The 'tost'-style tail hook assembly was bent upward; contacting and damaging the rudder. Whose fault: although the glider pilot and wing runner had given the signal to take off; the responsibility to assure the slack was removed was clearly mine. Somehow I missed it. Why/what would have helped? Possible contributing factors: poor sleep; heat-related fatigue (approximately 90 degrees F); moderate dehydration; and hunger. Differences which could have prevented or mitigated the event: experienced reliable assistance personnel (wing runner). The addition of a red funnel near the glider's end of the tope rope (the raising of the funnel off the ground had been a definite telltale of slack removed when used in the past). Better larger non-vibrating mirrors installed on the tow plane. Pilot hand positioned on or near tow rope release lever after setting full power.

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Original NASA ASRS Text

Title: GLIDER TOW PLT OF PA25 STARTS FULL POWER TKOF ROLL WHILE LINE TO GLIDER IS STILL SLACK. SUBSEQUENT EMERGENCY BRAKING CAUSES TOW PLANE TO NOSE OVER DAMAGING PROP; ENGINE AND TOW APPARATUS.

Narrative: AS A TOW PLT FOR A GLIDERPORT; I WAS PREPARING FOR THE 8TH LAUNCH OF A FAIRLY BUSY AFTERNOON. THE TOW ROPE (ABOUT 200 FT) NORMALLY REMAINED ATTACHED TO THE TOW PLANE THROUGH ALL PHASES OF THE OP. FOR EFFICIENCY; I HAD TAXIED THE TOW PLANE TO POS THE GLIDER'S END OF THE TOW ROPE WITHIN EASY REACH FOR HOOK-UP TO THE GLIDER. I THEN TAXIED FORWARD; LINING UP IN FRONT OF THE GLIDER AND POSITIONING THE TOW PLANE FAR ENOUGH AWAY TO MINIMIZE THE PROP WASH BLOWING THE 2 MEN WHO WOULD BE IN THE GLIDER. IT APPEARED THAT THE 'RIDE PLT' WAS ASSISTING THE CUSTOMER GETTING SETTLED INTO THE FRONT SEAT. I LEFT A SIGNIFICANT AMOUNT OF SLACK IN THE ROPE TO ALLOW FOR GLIDER HOOK-UP AND/OR TO PRECLUDE MOVING THE GLIDER FORWARD BEFORE THEY WERE IN AND READY. I THEN OCCUPIED MYSELF WITH THE PRETKOF CHKLIST. A FEW MINS LATER I SAW IN THE TOW PLANE'S MIRROR THAT THE GLIDER'S CANOPY WAS CLOSING AND THE WING WAS BEING RAISED BY THE 'WING RUNNER.' THE WING RUNNER WAS A BOY LOOKING TO BE 8-10 YRS OLD. HE ACTED UNCERTAIN; CONFIRMING TO ME THAT I WOULD RELY ON SIGNALS FROM THE GLIDER; NOT JUST HIM. THE RUDDER ON THE GLIDER FANNED A FEW TIMES AND THE BOY CONFIRMED WITH THE CIRCULAR WAVE 'LAUNCH' SIGNAL. I QUICKLY SCANNED THE PATTERN AND RWY FOR CONFLICTS AND RESPONDED BY FANNING THE TOW PLANE RUDDER. THIS CONFIRMED THAT I WAS ABOUT TO TAKE OFF. I APPLIED FULL PWR AND CHKED THE ENG GAUGES. AS THE TOW PLANE ACCELERATED; I GLANCED AT THE GLIDER IN THE MIRROR. INSTEAD OF SEEING THE GLIDER'S START; I SAW THE ROPE QUICKLY MOVING AS THE REMAINING SLACK WAS TAKEN UP. I IMMEDIATELY PULLED THE THROTTLE BACK AND APPLIED THE BRAKES HEAVILY. THE NOSE PITCHED DOWNWARD AND THE PROP CUT INTO THE GRASS RWY. THE ENG STOPPED IN ABOUT 10-15 REVOLUTIONS. IN THE NEXT FEW MOMENTS; THE TAIL CAME BACK DOWN WITH A THUD. NO ONE WAS HURT. I WAS UNINJURED. I TURNED OFF THE ACFT'S ELECTRICAL SWITCHES; MAGNETOS AND SHUT OFF THE FUEL. I GOT OUT; GLANCED AT THE DAMAGE; AND WALKED BACK TO CHK THE PEOPLE IN THE GLIDER. THEY AND THE BOY WERE PHYSICALLY UNAFFECTED. SINCE THE TOW PLANE STOPPED BEFORE THE ROPE'S SLACK WAS ENTIRELY TAKEN UP; THE GLIDER NEVER MOVED. DAMAGE TO THE TOW PLANE: TO THE NAKED EYE; THE PROP WAS WORN AND 1 BLADE WAS BENT. ENG DAMAGE IS UNKNOWN AT THE TIME OF THIS WRITING. 2 LEAVES OF THE TAILWHEEL SPRINGS BROKE. THE 'TOST'-STYLE TAIL HOOK ASSEMBLY WAS BENT UPWARD; CONTACTING AND DAMAGING THE RUDDER. WHOSE FAULT: ALTHOUGH THE GLIDER PLT AND WING RUNNER HAD GIVEN THE SIGNAL TO TAKE OFF; THE RESPONSIBILITY TO ASSURE THE SLACK WAS REMOVED WAS CLRLY MINE. SOMEHOW I MISSED IT. WHY/WHAT WOULD HAVE HELPED? POSSIBLE CONTRIBUTING FACTORS: POOR SLEEP; HEAT-RELATED FATIGUE (APPROX 90 DEGS F); MODERATE DEHYDRATION; AND HUNGER. DIFFERENCES WHICH COULD HAVE PREVENTED OR MITIGATED THE EVENT: EXPERIENCED RELIABLE ASSISTANCE PERSONNEL (WING RUNNER). THE ADDITION OF A RED FUNNEL NEAR THE GLIDER'S END OF THE TOPE ROPE (THE RAISING OF THE FUNNEL OFF THE GND HAD BEEN A DEFINITE TELLTALE OF SLACK REMOVED WHEN USED IN THE PAST). BETTER LARGER NON-VIBRATING MIRRORS INSTALLED ON THE TOW PLANE. PLT HAND POSITIONED ON OR NEAR TOW ROPE RELEASE LEVER AFTER SETTING FULL PWR.

Data retrieved from NASA's ASRS site as of January 2009 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.