I had the same problem although it was upon landing. I've ben flying tail draggers for a while along with various warbirds and felt comfortable flying the Extra. I had the plane setup with the required CG and on low rates. The take off went fine but needed quite a bit of up elevator trim to get it to fly level. I flew it 5 times around the field at altitude then started my approach on the downwind leg.

Downwind to base went fine, but when I turned final it rolled hard right nose down and went in. I was about 35-40 ft up and once it started to nose in I didn't have any control at all. I assume that I just got it too slow for it's liking at those settings. Luckily the wing remained intact, it ripped the wing holdown out which took the brunt of the hit, but I had some hard impact damage to the firewall back to the cockpit on the right side.

The plane has since been fixed and I do all of my flying on high rates and moved the CG back about 1/4" which took some weight off the nose. I didn't change any of my approach speeds, but on high rates I have much more control. I think the nose heaviness of the plane along with the low rates at that approach speed all combined to the crash.

All in all I am happy with the plane and it still flies great after the repairs.