right landing gear collapse
 

Anyone had or heard of one leg of landing gear collapsing after landing with down lock light (green) lit and tower fly by confirming gear down appearing normal?

What model? The gear system is vastly different with pre '73 vs original 337. The green light is only an indication of the nose gear not the mains. In the newer post '72 models (G) the mains have separate actuators for each of the two main gear. I would say that there could be a problem with one side and not the other. What happened?

1972 Serial No. 00025 T337G. Normal approach, downlock thunk didn't seem right ( but had green light) so did a tower flyby. Tower said 3 down ,looked normal, cleared to land. Touchdown seemed normal, second later right leg folded back and we went a short ride on the wingtip into the grass. The wheel collapsed against the closed gear door and kept the belly from scraping.
No prop strike. Some wing tip damage to plastic and end rib, and rear dorsal fin

landing gear collapse
 

After dealing with the bureaucracy and ferrying the plane home, we found the rotary gear actuator cylinder had cracked all along the casting seam flushing out all the hydraulic fluid.
Don't know if common with 337's - never happened before in the 45 years I've had a T337P. No one seems to know about this issue although another area of cracking for the RG's and 210's has been reported.

The other problem is that the cylinders are not easily accessed through a pressure bulkhead and would be difficult to inspect.

Apparently one RG driver found that after a similar failure (cracked in a different area) he could gyrate the plane in a way that managed to lock the gear down.
Might come in handy sometime.