A homebuilt sailplane's tail wheel steering clip failed on takeoff unbeknown to the pilot so that on landing he lost control of the aircraft as the tail wheel touched down; damaging the aircraft.

Narrative

Glider had a hard left turn on takeoff behind tow-plane. I overcame it by full right-hand rudder and right-hand stick input. Flew for 2.5 hours to 14;500 FT. I landed glider on centerline in winds less than 10 KTS. As tail wheel touched; a hard left turn [was] experienced with left wing on ground. Right-hand wing contacted a runway light; breaking it off; and causing leading edge dent on right-hand wing; one inch by 2 inch; and right-hand inboard flap section skin tear. Disconnection of tail cone revealed steering spring clip (spring connected to rudder push rod and tail wheel steering horn) had disconnected due to right-hand full rudder deflection and/or ground handling that caused the clip disconnection. Clip is 'C' shaped; bent over spring and horn (no safety).Corrective action: 1) Redesign of steering spring clip to mimic 'paper clip' so any spring of horn connection cannot be opened or disconnected; 2) Removal of tail cone and rebuild [it] with [an] inspection port (window) to inspect same on preflight.