Narrative:

During a landing at an 1800 ft private grass strip, my RV3 began to yaw to the right near the end of the rollout. Full left rudder was applied then hard left brake. The aircraft continued to yaw to the right and a ground loop began. When the aircraft was at the right edge of the mowed area of the grass strip and almost pointed 90 degrees to the right, the left gear leg mount tore from the engine mount and collapsed under the fuselage. This resulted in the propeller and the left wingtip striking the ground. No injuries or property damage other than to the aircraft occurred. At the time, winds were calm and the grass surface was cut and dry. The ground loop occurred during that portion of the rollout where the rudder was not effective due to low speed and tailwheel steering and differential braking were not enough to maintain directional control on the grass surface once the yaw began. A short application of power might have increased rudder effectiveness and avoided the ground loop. Since I have never needed to use that corrective action in the past, it did not occur to me to use it at the critical moment.

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Original NASA ASRS Text

Title: AN RV3 PLT LOSES CTL OF HIS ACFT ON LNDG RESULTING IN A GND LOOP, GEAR COLLAPSE, AND PROP STRIKE. NO INJURIES.

Narrative: DURING A LNDG AT AN 1800 FT PVT GRASS STRIP, MY RV3 BEGAN TO YAW TO THE R NEAR THE END OF THE ROLLOUT. FULL L RUDDER WAS APPLIED THEN HARD L BRAKE. THE ACFT CONTINUED TO YAW TO THE R AND A GND LOOP BEGAN. WHEN THE ACFT WAS AT THE R EDGE OF THE MOWED AREA OF THE GRASS STRIP AND ALMOST POINTED 90 DEGS TO THE R, THE L GEAR LEG MOUNT TORE FROM THE ENG MOUNT AND COLLAPSED UNDER THE FUSELAGE. THIS RESULTED IN THE PROP AND THE L WINGTIP STRIKING THE GND. NO INJURIES OR PROPERTY DAMAGE OTHER THAN TO THE ACFT OCCURRED. AT THE TIME, WINDS WERE CALM AND THE GRASS SURFACE WAS CUT AND DRY. THE GND LOOP OCCURRED DURING THAT PORTION OF THE ROLLOUT WHERE THE RUDDER WAS NOT EFFECTIVE DUE TO LOW SPD AND TAILWHEEL STEERING AND DIFFERENTIAL BRAKING WERE NOT ENOUGH TO MAINTAIN DIRECTIONAL CTL ON THE GRASS SURFACE ONCE THE YAW BEGAN. A SHORT APPLICATION OF PWR MIGHT HAVE INCREASED RUDDER EFFECTIVENESS AND AVOIDED THE GND LOOP. SINCE I HAVE NEVER NEEDED TO USE THAT CORRECTIVE ACTION IN THE PAST, IT DID NOT OCCUR TO ME TO USE IT AT THE CRITICAL MOMENT.

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.