After alleged normal approach and landing, during rollout, gear of small aircraft collapsed.

Attributes
ACN	132824
Time
Date	198912
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : apc
State Reference	CA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	landing other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 27 flight time total : 1280 flight time type : 550
ASRS Report	132824
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other controllera other other : unspecified cockpit
Resolutory Action	none taken : detected after the fact
Consequence	other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

As I completed my landing rollout after landing my small aircraft at apc, my landing gear collapsed. My passenger and I exited the aircraft, uninjured, and awaited assistance. The approach and landing had been normal to that point. I had lowered the landing gear, a manual 'johnson bar' arrangement, and checked it in place by seeing and feeling the bar in it slot and observing the gear down light on the instrument panel. The landing was smooth and rollout normal until the gear collapsed. A discussion with napa tower personnel indicated they had observed the landing and rollout directly in front of them and had noted nothing unusual. They said that in fact they were in the process of keying their microphone to direct me to do a 180 degree turn and back-taxi to parking, since they had seen an apparently normal landing/roll/slowdown, and I appeared to be ready for that direction. I had no indication my landing gear was unsafe from my indications onboard. I feel, and have been told by aircraft maintenance experts, that a worn bushing on the nose gear can unseat the gear and collapse it. I had felt a nose shimmy the previous 2 lndgs. Runway 24 at napa has some large bumps and I think I hit one, causing my loose nose gear to dislodge the gear.

Original NASA ASRS Text

Title: AFTER ALLEGED NORMAL APCH AND LNDG, DURING ROLLOUT, GEAR OF SMA COLLAPSED.

Narrative: AS I COMPLETED MY LNDG ROLLOUT AFTER LNDG MY SMA AT APC, MY LNDG GEAR COLLAPSED. MY PAX AND I EXITED THE ACFT, UNINJURED, AND AWAITED ASSISTANCE. THE APCH AND LNDG HAD BEEN NORMAL TO THAT POINT. I HAD LOWERED THE LNDG GEAR, A MANUAL 'JOHNSON BAR' ARRANGEMENT, AND CHKED IT IN PLACE BY SEEING AND FEELING THE BAR IN IT SLOT AND OBSERVING THE GEAR DOWN LIGHT ON THE INSTRUMENT PANEL. THE LNDG WAS SMOOTH AND ROLLOUT NORMAL UNTIL THE GEAR COLLAPSED. A DISCUSSION WITH NAPA TWR PERSONNEL INDICATED THEY HAD OBSERVED THE LNDG AND ROLLOUT DIRECTLY IN FRONT OF THEM AND HAD NOTED NOTHING UNUSUAL. THEY SAID THAT IN FACT THEY WERE IN THE PROCESS OF KEYING THEIR MIC TO DIRECT ME TO DO A 180 DEG TURN AND BACK-TAXI TO PARKING, SINCE THEY HAD SEEN AN APPARENTLY NORMAL LNDG/ROLL/SLOWDOWN, AND I APPEARED TO BE READY FOR THAT DIRECTION. I HAD NO INDICATION MY LNDG GEAR WAS UNSAFE FROM MY INDICATIONS ONBOARD. I FEEL, AND HAVE BEEN TOLD BY ACFT MAINT EXPERTS, THAT A WORN BUSHING ON THE NOSE GEAR CAN UNSEAT THE GEAR AND COLLAPSE IT. I HAD FELT A NOSE SHIMMY THE PREVIOUS 2 LNDGS. RWY 24 AT NAPA HAS SOME LARGE BUMPS AND I THINK I HIT ONE, CAUSING MY LOOSE NOSE GEAR TO DISLODGE THE GEAR.

Data retrieved from NASA's ASRS site as of August 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.