A C310 gear collapses on landing. All gear signals were 'green' on the approach.

Attributes
ACN	417268
Time
Date	199810
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ftw
State Reference	TX
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : instructional
Make Model Name	Cessna 310/T310C
Operating Under FAR Part	Part 91
Flight Phase	descent : approach landing other
Flight Plan	None
Person 1
Affiliation	Other
Function	instruction : instructor oversight : pic
Qualification	pilot : cfi
Experience	flight time last 90 days : 250 flight time total : 950 flight time type : 110
ASRS Report	417268
Person 2
Affiliation	Other
Function	flight crew : single pilot instruction : trainee
Qualification	pilot : private
Events
Anomaly	aircraft equipment problem : critical conflict : ground critical other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	none taken : unable
Consequence	other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

I was on downwind. I reduced power, I heard the gear horn. I extended the gear, the light was green, the horn stopped. I touched down on the main gear. I felt the impact on the main gear, then I started sinking more and more until the nosewheel hit the ground, then I continued to sink until I felt the belly on the runway. I didn't panic, I kept control of the airplane on the centerline to a full stop. I evacuate/evacuationed the airplane with the student and the passenger. Nobody was hurt. The owner of the airplane came into the airplane first after we evacuate/evacuationed it. He saw the gear knob on down position. The tower said they saw the gear down but unlocked. They tried to call us to go around, we didn't hear it. None of us heard the radio, none of us heard the gear horn on final when I had the power on idle. The passenger saw the gear light on green. The pilot says that it was not red, and I saw the green and the gear in the wingtip mirrors.

Original NASA ASRS Text

Title: A C310 GEAR COLLAPSES ON LNDG. ALL GEAR SIGNALS WERE 'GREEN' ON THE APCH.

Narrative: I WAS ON DOWNWIND. I REDUCED PWR, I HEARD THE GEAR HORN. I EXTENDED THE GEAR, THE LIGHT WAS GREEN, THE HORN STOPPED. I TOUCHED DOWN ON THE MAIN GEAR. I FELT THE IMPACT ON THE MAIN GEAR, THEN I STARTED SINKING MORE AND MORE UNTIL THE NOSEWHEEL HIT THE GND, THEN I CONTINUED TO SINK UNTIL I FELT THE BELLY ON THE RWY. I DIDN'T PANIC, I KEPT CTL OF THE AIRPLANE ON THE CTRLINE TO A FULL STOP. I EVACED THE AIRPLANE WITH THE STUDENT AND THE PAX. NOBODY WAS HURT. THE OWNER OF THE AIRPLANE CAME INTO THE AIRPLANE FIRST AFTER WE EVACED IT. HE SAW THE GEAR KNOB ON DOWN POS. THE TWR SAID THEY SAW THE GEAR DOWN BUT UNLOCKED. THEY TRIED TO CALL US TO GAR, WE DIDN'T HEAR IT. NONE OF US HEARD THE RADIO, NONE OF US HEARD THE GEAR HORN ON FINAL WHEN I HAD THE PWR ON IDLE. THE PAX SAW THE GEAR LIGHT ON GREEN. THE PLT SAYS THAT IT WAS NOT RED, AND I SAW THE GREEN AND THE GEAR IN THE WINGTIP MIRRORS.

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.