GA small aircraft gear strut failure. Strut was collapsed causing loss of aircraft control.

Attributes
ACN	111971
Time
Date	198905
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : pao
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 : private
Experience	flight time last 90 days : 44 flight time total : 262 flight time type : 132
ASRS Report	111971
Events
Anomaly	aircraft equipment problem : less severe other anomaly
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Normal T/D, plane veered to left after hard sink on left side. Pilot maintained satisfactory control off runway in grass and brought plane to stop on parallel taxiway. Mechanical failure upon mechanical inspection: left main gear strut seal failure and gear not extended all the way. Normal flare and T/D for lights wind conditions--hard sink symptomatic of wind shear or premature stall of which neither condition existed. After veering to the left, pilot regained satisfactory control to keep aircraft in original direction of flight where ground looping was very inevitable. (Parked planes in immediate vicinity). Factors affecting pilot performance--pilot training in severe crosswind conditions and base airport is dominant in that condition. Therefore, directional control training very good. Pilot has calm personality and does not panic in stressful non-predetermined situations. Condition of left gear strut seal is not detectable upon preflight inspection of aircraft.

Original NASA ASRS Text

Title: GA SMA GEAR STRUT FAILURE. STRUT WAS COLLAPSED CAUSING LOSS OF ACFT CONTROL.

Narrative: NORMAL T/D, PLANE VEERED TO LEFT AFTER HARD SINK ON LEFT SIDE. PLT MAINTAINED SATISFACTORY CONTROL OFF RWY IN GRASS AND BROUGHT PLANE TO STOP ON PARALLEL TXWY. MECHANICAL FAILURE UPON MECHANICAL INSPECTION: LEFT MAIN GEAR STRUT SEAL FAILURE AND GEAR NOT EXTENDED ALL THE WAY. NORMAL FLARE AND T/D FOR LIGHTS WIND CONDITIONS--HARD SINK SYMPTOMATIC OF WIND SHEAR OR PREMATURE STALL OF WHICH NEITHER CONDITION EXISTED. AFTER VEERING TO THE LEFT, PLT REGAINED SATISFACTORY CONTROL TO KEEP ACFT IN ORIGINAL DIRECTION OF FLT WHERE GND LOOPING WAS VERY INEVITABLE. (PARKED PLANES IN IMMEDIATE VICINITY). FACTORS AFFECTING PLT PERFORMANCE--PLT TRNING IN SEVERE XWIND CONDITIONS AND BASE ARPT IS DOMINANT IN THAT CONDITION. THEREFORE, DIRECTIONAL CONTROL TRNING VERY GOOD. PLT HAS CALM PERSONALITY AND DOES NOT PANIC IN STRESSFUL NON-PREDETERMINED SITUATIONS. CONDITION OF LEFT GEAR STRUT SEAL IS NOT DETECTABLE UPON PREFLT INSPECTION OF ACFT.

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.