Narrative:

It was a sunny and clear morning; with a forecast of clouds forming in the afternoon with a possibility of scattered thunderstorms; the usual forecast for august. While the plane had been at anchor the wind had come up from the east and the waves had grown to perhaps 4 to 6 inches. Not a problem; noisy; but not unusual. Start off was normal except for use of maximum aileron to keep the port float out of the water while the plane proceeded to get on the step and accelerated toward approaching liftoff. I concentrated on keeping the left float clear of the waves. The plane then lifted off prematurely; probably because of my concentration on getting airborne as soon as possible. Not having quite enough airspeed; the plane settled back on the water. While I concentrated on keeping the wings level I let the nose down a bit to reduce drag and increase acceleration. Obviously I went too far because we both recall several large 'bumpy' waves at this point. Hitting them resulted in a water loop terminated by an abrupt 180 degree turn during which both floats; I found out later; had separated from the aircraft. This is what they are supposed to do under these circumstances to save damage to the wings. The port one broke loose completely and the other came loose; but continued to hang on under the wing on the starboard side. Coming to rest; we were in the middle of the lake with the nearest shore a mi or two away. This was no place to be stranded in a sinking boat or airplane. The first thing to do was to get contact with civilization and to let someone know our location in case we might not make it to shore. I didn't hesitate to declare an emergency and called 121.5 while at the same time getting underway to attempt to taxi to the nearest shoreland. Steering was impossible because of the drag of the hanging starboard float. However; with full power I did get the plane into a plow taxi and with the air rudder and water rudder hard over to port we could barely manage a straight line to get to shore. The camp was still a mi or so away. After safely getting back on to a sandy bottom in knee deep water I called to request the 'emergency' be canceled. The 2 souls aboard had arrived safely ashore without having to swim and the plane remained afloat. While this was an unfortunate event; the lessons learned are multiple. First; starting with an analysis and review of the entire incident; a number of contributing factors became apparent. Second; the imbal was caused by water which was leaking into the port side float. Third; this water entered through the access cover near the bottom of the float. Fourth; this cover had been removed a week previously to service the stuck drain plug and replaced by me without adding new sealing compound. Fifth; no test of the water tightness of the cover was made at that time. Sixth; wind and waves had increased considerably at the center of the lake prior to the attempted takeoff. How could this mishap have been avoided? 1) I could have caulked the cover. 2) I could have canceled the flight. 3) I could have taken off quickly before the float filled up. 4) I could have drained the float (possible only because I could have stood on the bottom to do it). 5) I could have done a better takeoff. Any one of these would have worked! My advice: what might appear to be minor can; when taken in combination; turn out to be major indeed! Don't take shortcuts. Play it safe. Save lives and money.

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Original NASA ASRS Text

Title: LA-4 ATTEMPTED WATER TKOF WITH ONE WING FLOAT PARTIALLY FILLED WITH WATER. THIS RESULTED IN AN UNCONTROLLED 180 DEGREE TURN AND FLOAT SEPARATION.

Narrative: IT WAS A SUNNY AND CLR MORNING; WITH A FORECAST OF CLOUDS FORMING IN THE AFTERNOON WITH A POSSIBILITY OF SCATTERED TSTMS; THE USUAL FORECAST FOR AUGUST. WHILE THE PLANE HAD BEEN AT ANCHOR THE WIND HAD COME UP FROM THE E AND THE WAVES HAD GROWN TO PERHAPS 4 TO 6 INCHES. NOT A PROB; NOISY; BUT NOT UNUSUAL. START OFF WAS NORMAL EXCEPT FOR USE OF MAX AILERON TO KEEP THE PORT FLOAT OUT OF THE WATER WHILE THE PLANE PROCEEDED TO GET ON THE STEP AND ACCELERATED TOWARD APCHING LIFTOFF. I CONCENTRATED ON KEEPING THE L FLOAT CLR OF THE WAVES. THE PLANE THEN LIFTED OFF PREMATURELY; PROBABLY BECAUSE OF MY CONCENTRATION ON GETTING AIRBORNE ASAP. NOT HAVING QUITE ENOUGH AIRSPD; THE PLANE SETTLED BACK ON THE WATER. WHILE I CONCENTRATED ON KEEPING THE WINGS LEVEL I LET THE NOSE DOWN A BIT TO REDUCE DRAG AND INCREASE ACCELERATION. OBVIOUSLY I WENT TOO FAR BECAUSE WE BOTH RECALL SEVERAL LARGE 'BUMPY' WAVES AT THIS POINT. HITTING THEM RESULTED IN A WATER LOOP TERMINATED BY AN ABRUPT 180 DEG TURN DURING WHICH BOTH FLOATS; I FOUND OUT LATER; HAD SEPARATED FROM THE ACFT. THIS IS WHAT THEY ARE SUPPOSED TO DO UNDER THESE CIRCUMSTANCES TO SAVE DAMAGE TO THE WINGS. THE PORT ONE BROKE LOOSE COMPLETELY AND THE OTHER CAME LOOSE; BUT CONTINUED TO HANG ON UNDER THE WING ON THE STARBOARD SIDE. COMING TO REST; WE WERE IN THE MIDDLE OF THE LAKE WITH THE NEAREST SHORE A MI OR TWO AWAY. THIS WAS NO PLACE TO BE STRANDED IN A SINKING BOAT OR AIRPLANE. THE FIRST THING TO DO WAS TO GET CONTACT WITH CIVILIZATION AND TO LET SOMEONE KNOW OUR LOCATION IN CASE WE MIGHT NOT MAKE IT TO SHORE. I DIDN'T HESITATE TO DECLARE AN EMER AND CALLED 121.5 WHILE AT THE SAME TIME GETTING UNDERWAY TO ATTEMPT TO TAXI TO THE NEAREST SHORELAND. STEERING WAS IMPOSSIBLE BECAUSE OF THE DRAG OF THE HANGING STARBOARD FLOAT. HOWEVER; WITH FULL PWR I DID GET THE PLANE INTO A PLOW TAXI AND WITH THE AIR RUDDER AND WATER RUDDER HARD OVER TO PORT WE COULD BARELY MANAGE A STRAIGHT LINE TO GET TO SHORE. THE CAMP WAS STILL A MI OR SO AWAY. AFTER SAFELY GETTING BACK ON TO A SANDY BOTTOM IN KNEE DEEP WATER I CALLED TO REQUEST THE 'EMER' BE CANCELED. THE 2 SOULS ABOARD HAD ARRIVED SAFELY ASHORE WITHOUT HAVING TO SWIM AND THE PLANE REMAINED AFLOAT. WHILE THIS WAS AN UNFORTUNATE EVENT; THE LESSONS LEARNED ARE MULTIPLE. FIRST; STARTING WITH AN ANALYSIS AND REVIEW OF THE ENTIRE INCIDENT; A NUMBER OF CONTRIBUTING FACTORS BECAME APPARENT. SECOND; THE IMBAL WAS CAUSED BY WATER WHICH WAS LEAKING INTO THE PORT SIDE FLOAT. THIRD; THIS WATER ENTERED THROUGH THE ACCESS COVER NEAR THE BOTTOM OF THE FLOAT. FOURTH; THIS COVER HAD BEEN REMOVED A WEEK PREVIOUSLY TO SVC THE STUCK DRAIN PLUG AND REPLACED BY ME WITHOUT ADDING NEW SEALING COMPOUND. FIFTH; NO TEST OF THE WATER TIGHTNESS OF THE COVER WAS MADE AT THAT TIME. SIXTH; WIND AND WAVES HAD INCREASED CONSIDERABLY AT THE CTR OF THE LAKE PRIOR TO THE ATTEMPTED TKOF. HOW COULD THIS MISHAP HAVE BEEN AVOIDED? 1) I COULD HAVE CAULKED THE COVER. 2) I COULD HAVE CANCELED THE FLT. 3) I COULD HAVE TAKEN OFF QUICKLY BEFORE THE FLOAT FILLED UP. 4) I COULD HAVE DRAINED THE FLOAT (POSSIBLE ONLY BECAUSE I COULD HAVE STOOD ON THE BOTTOM TO DO IT). 5) I COULD HAVE DONE A BETTER TKOF. ANY ONE OF THESE WOULD HAVE WORKED! MY ADVICE: WHAT MIGHT APPEAR TO BE MINOR CAN; WHEN TAKEN IN COMBINATION; TURN OUT TO BE MAJOR INDEED! DON'T TAKE SHORTCUTS. PLAY IT SAFE. SAVE LIVES AND MONEY.

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.