The right landing gear of an small aircraft folded after landing.

Attributes
ACN	258732
Time
Date	199312
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : s13
State Reference	WA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : pvd
Operator	general aviation : instructional
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	descent : approach landing other
Flight Plan	None
Person 1
Affiliation	Other
Function	instruction : instructor
Qualification	pilot : instrument pilot : commercial pilot : atp pilot : cfi
Experience	flight time last 90 days : 130 flight time total : 26000 flight time type : 19
ASRS Report	258732
Person 2
Affiliation	Other
Function	instruction : trainee
Qualification	pilot : private
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Upon level off at 1800 ft about 1 1/2 mi north of martha lake, I pulled power to idle to simulate an engine failure. The airplane is an small aircraft with an automatic landing gear extension feature. My student pinned the override to keep the landing gear retracted and completed the engine restart procedure while establishing a glide toward the airport. Flaps were set at 10 degrees on about a 3/4 mi final, followed by the landing gear extension. I rechked the landing gear switch down green lights, auxiliary pump 'on' and override released and decided we looked ok for a full stop landing. Spi extended 40 degrees flaps on short final and the touchdown about 400 ft past the threshold was in a nose high attitude and seemed normal. Shortly after landing, the right wing began to lower and the landing gear warning horn sounded as the airplane pulled to the right and slid to a stop angled about 20 degrees off runway direction with the right main landing gear collapsed on the grass. The nose gear and left main landing gear remained extended and the right gear was manually extended and locked to clear the airplane from the runway. In this case, the gear down indications (landing gear switch, green lights, and warning horn) were positive, although the down lock apparently released during rollout. Damage was limited to the right flap and aileron.

Original NASA ASRS Text

Title: THE R LNDG GEAR OF AN SMA FOLDED AFTER LNDG.

Narrative: UPON LEVEL OFF AT 1800 FT ABOUT 1 1/2 MI N OF MARTHA LAKE, I PULLED PWR TO IDLE TO SIMULATE AN ENG FAILURE. THE AIRPLANE IS AN SMA WITH AN AUTOMATIC LNDG GEAR EXTENSION FEATURE. MY STUDENT PINNED THE OVERRIDE TO KEEP THE LNDG GEAR RETRACTED AND COMPLETED THE ENG RESTART PROC WHILE ESTABLISHING A GLIDE TOWARD THE ARPT. FLAPS WERE SET AT 10 DEGS ON ABOUT A 3/4 MI FINAL, FOLLOWED BY THE LNDG GEAR EXTENSION. I RECHKED THE LNDG GEAR SWITCH DOWN GREEN LIGHTS, AUX PUMP 'ON' AND OVERRIDE RELEASED AND DECIDED WE LOOKED OK FOR A FULL STOP LNDG. SPI EXTENDED 40 DEGS FLAPS ON SHORT FINAL AND THE TOUCHDOWN ABOUT 400 FT PAST THE THRESHOLD WAS IN A NOSE HIGH ATTITUDE AND SEEMED NORMAL. SHORTLY AFTER LNDG, THE R WING BEGAN TO LOWER AND THE LNDG GEAR WARNING HORN SOUNDED AS THE AIRPLANE PULLED TO THE R AND SLID TO A STOP ANGLED ABOUT 20 DEGS OFF RWY DIRECTION WITH THE R MAIN LNDG GEAR COLLAPSED ON THE GRASS. THE NOSE GEAR AND L MAIN LNDG GEAR REMAINED EXTENDED AND THE R GEAR WAS MANUALLY EXTENDED AND LOCKED TO CLR THE AIRPLANE FROM THE RWY. IN THIS CASE, THE GEAR DOWN INDICATIONS (LNDG GEAR SWITCH, GREEN LIGHTS, AND WARNING HORN) WERE POSITIVE, ALTHOUGH THE DOWN LOCK APPARENTLY RELEASED DURING ROLLOUT. DAMAGE WAS LIMITED TO THE R FLAP AND AILERON.

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.