Narrative:

Our small aircraft was fuel full and loaded with 2 pilots and 2 passenger for VFR local flight. Non rated (in type) pilot in left seat. Normal cockpit indications of 3 gear sown on preflight. 3 green lights. Non rated pilot making the takeoff. About 65 KTS aircraft rotated after slower than normal acceleration. Stall warning sounded and student commanded to hold the aircraft on the ground until 80 KTS. At about 75-80 KTS the gear retracted and the aircraft slid to a stop on the grass runway. No injuries. Gear handle was found to be in the up position. I was positive that it was down for taxi out and takeoff as I had looked at it and saw 3 green lights. The handle was apparently in the up position the entire time however as the non rated pilot who was left alone in the aircraft for a few minutes after engine start said that his son also in the aircraft asked about the handle earlier and saw that it was up. His son wanted to know if the gear would come up on the ground. The other pilot told his son 'no'. He apparently did not understand how the system worked or he would have told me about the handle position. I am not sure if he moved the handle or the last pilot flying the aircraft the previous day with this same non rated pilot had moved it. In any case failure of me to spot the gear handle in the wrong position is the direct cause of the inadvertent and unintentional gear retraction. Contributing to the incident was the stall warning horn which is the same horn used in this model for the gear. It was not the stall warning horn but rather, the gear warning horn that was sounding. I feel certain that the poor acceleration on takeoff was because the non rated pilot who flies seaplanes for a living, was riding the brakes. He had done the same thing the previous day with the owner in another aircraft that had dual brakes. The slow acceleration and then the stall warning (false) led me to hold the aircraft on the runway longer than necessary (the non rated pilot was flying at this point. I commanded him to hold it down. The incident could have also probably been prevented had I assumed control of the aircraft when stall warning sounded as I have been flying this aircraft for 2 or 3 years now and was much more familiar with its feel (monday morning hindsight).) as the wing started lifting with the nose being held on the runway, the mains retracted, followed by the nose gear, at which point the nose fell onto the grass. The aircraft slid to a stop with all the gear retracted. There were no injuries.

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Original NASA ASRS Text

Title: LIGHT ACFT EXPERIENCES INADVERTENT LNDG GEAR RETRACTION DURING TKOF ROLL.

Narrative: OUR SMA WAS FUEL FULL AND LOADED WITH 2 PLTS AND 2 PAX FOR VFR LCL FLT. NON RATED (IN TYPE) PLT IN LEFT SEAT. NORMAL COCKPIT INDICATIONS OF 3 GEAR SOWN ON PREFLT. 3 GREEN LIGHTS. NON RATED PLT MAKING THE TKOF. ABOUT 65 KTS ACFT ROTATED AFTER SLOWER THAN NORMAL ACCELERATION. STALL WARNING SOUNDED AND STUDENT COMMANDED TO HOLD THE ACFT ON THE GND UNTIL 80 KTS. AT ABOUT 75-80 KTS THE GEAR RETRACTED AND THE ACFT SLID TO A STOP ON THE GRASS RWY. NO INJURIES. GEAR HANDLE WAS FOUND TO BE IN THE UP POSITION. I WAS POSITIVE THAT IT WAS DOWN FOR TAXI OUT AND TKOF AS I HAD LOOKED AT IT AND SAW 3 GREEN LIGHTS. THE HANDLE WAS APPARENTLY IN THE UP POSITION THE ENTIRE TIME HOWEVER AS THE NON RATED PLT WHO WAS LEFT ALONE IN THE ACFT FOR A FEW MINUTES AFTER ENGINE START SAID THAT HIS SON ALSO IN THE ACFT ASKED ABOUT THE HANDLE EARLIER AND SAW THAT IT WAS UP. HIS SON WANTED TO KNOW IF THE GEAR WOULD COME UP ON THE GND. THE OTHER PLT TOLD HIS SON 'NO'. HE APPARENTLY DID NOT UNDERSTAND HOW THE SYSTEM WORKED OR HE WOULD HAVE TOLD ME ABOUT THE HANDLE POSITION. I AM NOT SURE IF HE MOVED THE HANDLE OR THE LAST PLT FLYING THE ACFT THE PREVIOUS DAY WITH THIS SAME NON RATED PLT HAD MOVED IT. IN ANY CASE FAILURE OF ME TO SPOT THE GEAR HANDLE IN THE WRONG POSITION IS THE DIRECT CAUSE OF THE INADVERTENT AND UNINTENTIONAL GEAR RETRACTION. CONTRIBUTING TO THE INCIDENT WAS THE STALL WARNING HORN WHICH IS THE SAME HORN USED IN THIS MODEL FOR THE GEAR. IT WAS NOT THE STALL WARNING HORN BUT RATHER, THE GEAR WARNING HORN THAT WAS SOUNDING. I FEEL CERTAIN THAT THE POOR ACCELERATION ON TKOF WAS BECAUSE THE NON RATED PLT WHO FLIES SEAPLANES FOR A LIVING, WAS RIDING THE BRAKES. HE HAD DONE THE SAME THING THE PREVIOUS DAY WITH THE OWNER IN ANOTHER ACFT THAT HAD DUAL BRAKES. THE SLOW ACCELERATION AND THEN THE STALL WARNING (FALSE) LED ME TO HOLD THE ACFT ON THE RWY LONGER THAN NECESSARY (THE NON RATED PLT WAS FLYING AT THIS POINT. I COMMANDED HIM TO HOLD IT DOWN. THE INCIDENT COULD HAVE ALSO PROBABLY BEEN PREVENTED HAD I ASSUMED CONTROL OF THE ACFT WHEN STALL WARNING SOUNDED AS I HAVE BEEN FLYING THIS ACFT FOR 2 OR 3 YEARS NOW AND WAS MUCH MORE FAMILIAR WITH ITS FEEL (MONDAY MORNING HINDSIGHT).) AS THE WING STARTED LIFTING WITH THE NOSE BEING HELD ON THE RWY, THE MAINS RETRACTED, FOLLOWED BY THE NOSE GEAR, AT WHICH POINT THE NOSE FELL ONTO THE GRASS. THE ACFT SLID TO A STOP WITH ALL THE GEAR RETRACTED. THERE WERE NO INJURIES.

Data retrieved from NASA's ASRS site as of August 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.