Narrative:

Although I had a seaplane rating, I had never flown a lake and just wasn't familiar with it. I then had him taxi back to runway 21 and advised him to demonstrate a short field or maximum performance takeoff and landing. His takeoff was excellent and, on downwind, I advised him to imagine a 50 ft tree being right at the end of the runway and he would need to cross the end of the runway at approximately 100 ft AGL. His approach was excellent, very stable, with a constant airspeed somewhere around 80 KIAS or so I think, with a constant rate of descent. Gear and flaps were down, and he crossed the end of the runway in excellent or perfect position, about 100 ft AGL. But immediately after crossing the runway, he then put the plane in what I would call an excessive angle of descent. He really caught me by surprise, because I wasn't expecting this less than 100 ft off the ground. I immediately grabbed the wheel and pulled back but it was too late to avoid contact with the runway. The aircraft hit in a flat attitude, but it hit hard, breaking off the left main and damaging the nose gear. It also wrinkled the skin on the wings. I had never met or flown with xy before, so I don't know if he made all of his approachs like this or maybe this is something he picked up from the lake representative.

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Original NASA ASRS Text

Title: DAMAGED ACFT AS A RESULT OF A HARD LNDG.

Narrative: ALTHOUGH I HAD A SEAPLANE RATING, I HAD NEVER FLOWN A LAKE AND JUST WASN'T FAMILIAR WITH IT. I THEN HAD HIM TAXI BACK TO RWY 21 AND ADVISED HIM TO DEMONSTRATE A SHORT FIELD OR MAX PERFORMANCE TKOF AND LNDG. HIS TKOF WAS EXCELLENT AND, ON DOWNWIND, I ADVISED HIM TO IMAGINE A 50 FT TREE BEING RIGHT AT THE END OF THE RWY AND HE WOULD NEED TO CROSS THE END OF THE RWY AT APPROX 100 FT AGL. HIS APCH WAS EXCELLENT, VERY STABLE, WITH A CONSTANT AIRSPD SOMEWHERE AROUND 80 KIAS OR SO I THINK, WITH A CONSTANT RATE OF DSCNT. GEAR AND FLAPS WERE DOWN, AND HE CROSSED THE END OF THE RWY IN EXCELLENT OR PERFECT POS, ABOUT 100 FT AGL. BUT IMMEDIATELY AFTER XING THE RWY, HE THEN PUT THE PLANE IN WHAT I WOULD CALL AN EXCESSIVE ANGLE OF DSCNT. HE REALLY CAUGHT ME BY SURPRISE, BECAUSE I WASN'T EXPECTING THIS LESS THAN 100 FT OFF THE GND. I IMMEDIATELY GRABBED THE WHEEL AND PULLED BACK BUT IT WAS TOO LATE TO AVOID CONTACT WITH THE RWY. THE ACFT HIT IN A FLAT ATTITUDE, BUT IT HIT HARD, BREAKING OFF THE L MAIN AND DAMAGING THE NOSE GEAR. IT ALSO WRINKLED THE SKIN ON THE WINGS. I HAD NEVER MET OR FLOWN WITH XY BEFORE, SO I DON'T KNOW IF HE MADE ALL OF HIS APCHS LIKE THIS OR MAYBE THIS IS SOMETHING HE PICKED UP FROM THE LAKE REPRESENTATIVE.

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.