Narrative:

I was completing a training flight for insurance coverage having previously obtaining a tailwheel endorsement in different make and model. Pilot and instructor were returning from the airport where the proficiency training was conducted. I flew a normal approach to airport and runway 16. Wind approximately 140 at 5 KTS. Three point touchdown with a bounce; recovered straight ahead. Aircraft veered left; and then over-correction resulted in veer to the right. Aircraft exited right side of runway at slow speed. Aircraft impacted the side of a culvert damaging landing gear; aircraft belly; and propeller. No injuries to either occupant. Inspection of the tailwheel showed that both tailwheel springs missing. Inspection of the runway [had] located one spring at the approximate location of the initial touchdown. The second spring was found several days later in roughly the same area. Neither spring; nor the spring attachment clips; nor the rudder horn was damaged. The springs came off due to excessive slack and large gap on the spring attach hook. The slow speed made the rudder ineffective for directional control. Loss of tailwheel steering left the brakes as the only directional control. There was insufficient time and space due to narrow runway and adjacent drainage culverts for braking action to bring the aircraft under control. Aggravating the situation was the upward runway slope in the touchdown zone; narrower than standard runway; and the culvert close to the runway edge. The proper investigation would be to determine if the tailwheel springs were the correct parts for the installed tailwheel and if the resulting combination was properly rigged to resist shimmy and the risk of spring rejection.

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Original NASA ASRS Text

Title: Pilot reports both tailwheel springs had separated from an Aeronica-7AC aircraft on landing as he was completing a training flight. The missing springs caused the aircraft to veer left than right; exit the narrow runway; impacting a culvert; damaging landing gear; aircraft belly; and propeller; no injuries to occupants.

Narrative: I was completing a training flight for insurance coverage having previously obtaining a tailwheel endorsement in different make and model. Pilot and instructor were returning from the airport where the proficiency training was conducted. I flew a normal approach to airport and Runway 16. Wind approximately 140 at 5 KTS. Three point touchdown with a bounce; recovered straight ahead. Aircraft veered left; and then over-correction resulted in veer to the right. Aircraft exited right side of runway at slow speed. Aircraft impacted the side of a culvert damaging landing gear; aircraft belly; and propeller. No injuries to either occupant. Inspection of the tailwheel showed that both tailwheel springs missing. Inspection of the runway [had] located one spring at the approximate location of the initial touchdown. The second spring was found several days later in roughly the same area. Neither spring; nor the spring attachment clips; nor the rudder horn was damaged. The springs came off due to excessive slack and large gap on the spring attach hook. The slow speed made the rudder ineffective for directional control. Loss of tailwheel steering left the brakes as the only directional control. There was insufficient time and space due to narrow runway and adjacent drainage culverts for braking action to bring the aircraft under control. Aggravating the situation was the upward runway slope in the touchdown zone; narrower than standard runway; and the culvert close to the runway edge. The proper investigation would be to determine if the tailwheel springs were the correct parts for the installed tailwheel and if the resulting combination was properly rigged to resist shimmy and the risk of spring rejection.

Data retrieved from NASA's ASRS site as of July 2013 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.