Narrative:

The LA27 is a lake amphibian. During a water takeoff from lake buffum, fl, I aborted the takeoff after crossing the shoreline, landing the aircraft straight ahead in a grass pasture. The airframe suffered sheet metal damage to the underbody and float sponsons. Takeoff was into the wind, estimated at 9 KTS. Waves estimated at 10 inches ht. I estimated 3000+ ft of waterway was available for takeoff. Upon advancing power, the aircraft acceleration seemed normal. Rotation speed is 60 KTS. I glanced at airspeed indicator, saw 60 KTS and rotated while approaching shoreline. There were 2 of us on board. I am an instructor and was demonstrating rough water takeoff technique from the right seat. Upon rotation, my left seat pilot said 'your airspeed is only 45 KIAS.' as the rotation commenced, the stall warning sounded. This was my largest error. I definitely misread the airspeed indicator (placed on far upper l-hand side of instrument panel). Rotation of a lake amphibian into ground effect flight (which I was at) is well known in the lake community to produce no acceleration. Yes, the aircraft was not accelerating, so I reduced power and aborted to a rough field landing (gear up) in the grass pasture ahead. I secured the aircraft and we walked to a nearby road for assistance. Contributing factors: obviously, not allowing enough waterway for takeoff. I could have back-taxied further on lake buffum. Yes, I had 3000 ft waterway available, but it is a weak excuse not to have used more. The wind could have dropped off during acceleration. I normally take one last look at wind strength before acceleration. I do not remember doing so this time. I normally pick a go/no-go water abort point. This I did not do. This lack of discipline was clearly a large judgement error.

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Original NASA ASRS Text

Title: ROUGH WATER TKOF DEMONSTRATION ENDS WITH A BLEACHED LA27 WHEN AIRSPD IS MISREAD AND ROTATION IS STARTED TOO SLOW.

Narrative: THE LA27 IS A LAKE AMPHIBIAN. DURING A WATER TKOF FROM LAKE BUFFUM, FL, I ABORTED THE TKOF AFTER XING THE SHORELINE, LNDG THE ACFT STRAIGHT AHEAD IN A GRASS PASTURE. THE AIRFRAME SUFFERED SHEET METAL DAMAGE TO THE UNDERBODY AND FLOAT SPONSONS. TKOF WAS INTO THE WIND, ESTIMATED AT 9 KTS. WAVES ESTIMATED AT 10 INCHES HT. I ESTIMATED 3000+ FT OF WATERWAY WAS AVAILABLE FOR TKOF. UPON ADVANCING PWR, THE ACFT ACCELERATION SEEMED NORMAL. ROTATION SPD IS 60 KTS. I GLANCED AT AIRSPD INDICATOR, SAW 60 KTS AND ROTATED WHILE APCHING SHORELINE. THERE WERE 2 OF US ON BOARD. I AM AN INSTRUCTOR AND WAS DEMONSTRATING ROUGH WATER TKOF TECHNIQUE FROM THE R SEAT. UPON ROTATION, MY L SEAT PLT SAID 'YOUR AIRSPD IS ONLY 45 KIAS.' AS THE ROTATION COMMENCED, THE STALL WARNING SOUNDED. THIS WAS MY LARGEST ERROR. I DEFINITELY MISREAD THE AIRSPD INDICATOR (PLACED ON FAR UPPER L-HAND SIDE OF INST PANEL). ROTATION OF A LAKE AMPHIBIAN INTO GND EFFECT FLT (WHICH I WAS AT) IS WELL KNOWN IN THE LAKE COMMUNITY TO PRODUCE NO ACCELERATION. YES, THE ACFT WAS NOT ACCELERATING, SO I REDUCED PWR AND ABORTED TO A ROUGH FIELD LNDG (GEAR UP) IN THE GRASS PASTURE AHEAD. I SECURED THE ACFT AND WE WALKED TO A NEARBY ROAD FOR ASSISTANCE. CONTRIBUTING FACTORS: OBVIOUSLY, NOT ALLOWING ENOUGH WATERWAY FOR TKOF. I COULD HAVE BACK-TAXIED FURTHER ON LAKE BUFFUM. YES, I HAD 3000 FT WATERWAY AVAILABLE, BUT IT IS A WEAK EXCUSE NOT TO HAVE USED MORE. THE WIND COULD HAVE DROPPED OFF DURING ACCELERATION. I NORMALLY TAKE ONE LAST LOOK AT WIND STRENGTH BEFORE ACCELERATION. I DO NOT REMEMBER DOING SO THIS TIME. I NORMALLY PICK A GO/NO-GO WATER ABORT POINT. THIS I DID NOT DO. THIS LACK OF DISCIPLINE WAS CLRLY A LARGE JUDGEMENT ERROR.

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.