On Saturday I was part of a formation demo team at the EWB "Fun Day". At the end of the demo as we passed in front of the crowd, we stopped, 90 left and lead called "Smoke Now!" I hit the smoke button on my throttle as I pushed the power up to about 1700 RPM to increase the smoke volume. Despite full aft stick, in the blink of an eye, the tail rose. I chopped the power but it was too late. The momentum of the tail continued until the prop left it's signature in the taxiway. The tail then came down. Hard.
But why?!?! Simple, my flaps were still full down. If you have not yet seen or experienced it, the prop blast against the flaps will raise the tail of a typical (forward CG) RV-8 at around 1500 RPM even with full aft stick. I experienced this several years ago while doing an engine run but fortunately, was adding power slowly when the tail came up. On Saturday, I had momentarily forgotten the experience, didn't check flaps up prior to a quicker application of power. It was all over in an instant. Prop destroyed, engine to be torn down. The force of the tail coming down also put a bow in the tail spring so that will have to be replaced.
No injuries other than my pride and wallet.
It has since come to my attention that this is not a well known phenomenon so I post here to warn all, maybe prevent it from happening to someone else. Check flaps prior to advancing power above a low idle!!! If you feel that I have possibly saved you from a similar incident, the customary 5% contribution is appreciated. ;-)
But why?!?! Simple, my flaps were still full down. If you have not yet seen or experienced it, the prop blast against the flaps will raise the tail of a typical (forward CG) RV-8 at around 1500 RPM even with full aft stick. I experienced this several years ago while doing an engine run but fortunately, was adding power slowly when the tail came up. On Saturday, I had momentarily forgotten the experience, didn't check flaps up prior to a quicker application of power. It was all over in an instant. Prop destroyed, engine to be torn down. The force of the tail coming down also put a bow in the tail spring so that will have to be replaced.
No injuries other than my pride and wallet.
It has since come to my attention that this is not a well known phenomenon so I post here to warn all, maybe prevent it from happening to someone else. Check flaps prior to advancing power above a low idle!!! If you feel that I have possibly saved you from a similar incident, the customary 5% contribution is appreciated. ;-)