Amphibian has gear down lights but gear collapses on roll out when brakes applied.

Attributes
ACN	199253
Time
Date	199201
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : omn
State Reference	FL
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : fwa
Operator	general aviation : personal
Make Model Name	Small Aircraft
Flight Phase	landing other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : commercial pilot : cfi
Experience	flight time last 90 days : 135 flight time total : 4635 flight time type : 55
ASRS Report	199253
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other other : unspecified cockpit
Resolutory Action	none taken : unable
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Before landing gear was put down, got green light, visual showed all gear down. After landing on gear I put on the brakes and the gear went up laying the airplane on its keel (flying boat). We had to close the airport as men and equipment were on the runway to jack it back up. No damage was sustained. Upon inspection it appeared that the micro switch may have loosened indicating gear down and locked prematurely (this was fixed). I suggest inspection of (gear micro switch) adjustment on this airplane every 25 hours. The aircraft is an amphibian. Callback conversation with reporter revealed the following information: reporter states mechanic gave a written report stating this micro switch will occasionally give premature light indication but gear stops before locked. Visually gear appears to agree with lights and no way to know it is not locked. No real damage to aircraft, just scraped the keel a bit. Reporter feels the word should be spread and possibly a requirement to adjust every 25 hours to eliminate such incidents. There are still about 300 of these amphibians still flying.

Original NASA ASRS Text

Title: AMPHIBIAN HAS GEAR DOWN LIGHTS BUT GEAR COLLAPSES ON ROLL OUT WHEN BRAKES APPLIED.

Narrative: BEFORE LNDG GEAR WAS PUT DOWN, GOT GREEN LIGHT, VISUAL SHOWED ALL GEAR DOWN. AFTER LNDG ON GEAR I PUT ON THE BRAKES AND THE GEAR WENT UP LAYING THE AIRPLANE ON ITS KEEL (FLYING BOAT). WE HAD TO CLOSE THE ARPT AS MEN AND EQUIP WERE ON THE RWY TO JACK IT BACK UP. NO DAMAGE WAS SUSTAINED. UPON INSPECTION IT APPEARED THAT THE MICRO SWITCH MAY HAVE LOOSENED INDICATING GEAR DOWN AND LOCKED PREMATURELY (THIS WAS FIXED). I SUGGEST INSPECTION OF (GEAR MICRO SWITCH) ADJUSTMENT ON THIS AIRPLANE EVERY 25 HRS. THE ACFT IS AN AMPHIBIAN. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES MECH GAVE A WRITTEN RPT STATING THIS MICRO SWITCH WILL OCCASIONALLY GIVE PREMATURE LIGHT INDICATION BUT GEAR STOPS BEFORE LOCKED. VISUALLY GEAR APPEARS TO AGREE WITH LIGHTS AND NO WAY TO KNOW IT IS NOT LOCKED. NO REAL DAMAGE TO ACFT, JUST SCRAPED THE KEEL A BIT. RPTR FEELS THE WORD SHOULD BE SPREAD AND POSSIBLY A REQUIREMENT TO ADJUST EVERY 25 HRS TO ELIMINATE SUCH INCIDENTS. THERE ARE STILL ABOUT 300 OF THESE AMPHIBIANS STILL FLYING.

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.