The landing gear collapsed on an small aircraft.

Attributes
ACN	257684
Time
Date	199311
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : 30f
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	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	landing other other
Person 1
Affiliation	Other
Function	instruction : instructor
Qualification	pilot : commercial pilot : instrument pilot : cfi
Experience	flight time last 90 days : 62 flight time total : 636 flight time type : 156
ASRS Report	257684
Person 2
Affiliation	Other
Function	instruction : trainee
Qualification	pilot : private pilot : instrument
Experience	flight time last 90 days : 11 flight time total : 270 flight time type : 9
ASRS Report	257690
Events
Anomaly	aircraft equipment problem : critical non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

My student and I were practicing lndgs at lakeview airport. We were on downwind and proceeded through our 'gumpsf.' the student moved the johnson bar forward into the locking detent and we verified a green gear down indication. The landing proceeded normally. I instructed my student to line up on the turf runway. A green gear down indication was verified on final and we proceeded to land on the grass. Touchdown was gentle on the mains and we proceeded to roll out, the airplane shaking and vibrating rapidly on the turf. As the rollout continued, the gear horn sounded and I saw the johnson bar separate from the locking detent. The gear collapsed and the motor stopped as the plane skidded approximately 50 ft on its belly. As the acting PIC, I can say in good conscience that the gear indicator was green and the gear appeared to be locked. I, however, cannot say without a doubt that the gear was fully and securely locked. I did not reach up and grab the johnson bar to verify it was securely locked. Supplemental information from acn 257690: perhaps one of the key factors in this event was whether the johnson bar was really in the locked position. It appeared to me that I had locked this bar into position while lowering the gear. In addition, the instructor present indicated to me afterwards that the green light was lit, further confirming that the gear were down and locked.

Original NASA ASRS Text

Title: THE LNDG GEAR COLLAPSED ON AN SMA.

Narrative: MY STUDENT AND I WERE PRACTICING LNDGS AT LAKEVIEW ARPT. WE WERE ON DOWNWIND AND PROCEEDED THROUGH OUR 'GUMPSF.' THE STUDENT MOVED THE JOHNSON BAR FORWARD INTO THE LOCKING DETENT AND WE VERIFIED A GREEN GEAR DOWN INDICATION. THE LNDG PROCEEDED NORMALLY. I INSTRUCTED MY STUDENT TO LINE UP ON THE TURF RWY. A GREEN GEAR DOWN INDICATION WAS VERIFIED ON FINAL AND WE PROCEEDED TO LAND ON THE GRASS. TOUCHDOWN WAS GENTLE ON THE MAINS AND WE PROCEEDED TO ROLL OUT, THE AIRPLANE SHAKING AND VIBRATING RAPIDLY ON THE TURF. AS THE ROLLOUT CONTINUED, THE GEAR HORN SOUNDED AND I SAW THE JOHNSON BAR SEPARATE FROM THE LOCKING DETENT. THE GEAR COLLAPSED AND THE MOTOR STOPPED AS THE PLANE SKIDDED APPROX 50 FT ON ITS BELLY. AS THE ACTING PIC, I CAN SAY IN GOOD CONSCIENCE THAT THE GEAR INDICATOR WAS GREEN AND THE GEAR APPEARED TO BE LOCKED. I, HOWEVER, CANNOT SAY WITHOUT A DOUBT THAT THE GEAR WAS FULLY AND SECURELY LOCKED. I DID NOT REACH UP AND GRAB THE JOHNSON BAR TO VERIFY IT WAS SECURELY LOCKED. SUPPLEMENTAL INFO FROM ACN 257690: PERHAPS ONE OF THE KEY FACTORS IN THIS EVENT WAS WHETHER THE JOHNSON BAR WAS REALLY IN THE LOCKED POS. IT APPEARED TO ME THAT I HAD LOCKED THIS BAR INTO POS WHILE LOWERING THE GEAR. IN ADDITION, THE INSTRUCTOR PRESENT INDICATED TO ME AFTERWARDS THAT THE GREEN LIGHT WAS LIT, FURTHER CONFIRMING THAT THE GEAR WERE DOWN AND LOCKED.

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.