How Strong is the RV-8 tail?

[David-aviator]

Originally Posted by sf3543

Since we are talking about RV8 tails, I'll relate an issue I came across recently. It may actually belong in the thread about RV tail horror stories, but here goes.
I was asked to look at some cracks noticed on an RV8 rudder. The cracks were at the very top of the spar where the spar and counter weight arm come together.
It turned out that the two rivets that hold the spar to the top rib were not installed and only the skin was holding the top rib and counter weight to the rudder. Over the about 60 hours on the plane the skin started to tear.
I suppose the top of the rudder would have eventually torn off if left alone, but would have probably remained controllable for landing.
This plane was a second builder plane where the first builder built the empennage.
If nothing else, it emphasises the need for good pre-flight inspections and thorough condition inspections each year. Also,if you are building, don't under estimate the value of having other people look over your project. Anybody can miss something in their build and never notice it.
Sorry for thread drift.

Good post Steve. Thanks.

[Rogue Rocket]

Dan, I may have shared my personal experiences with you in the run up to Reno but also happy to share with everyone.

My Harmon Rocket II has a standard RV 4 tail with angle of incidence optimized for higher speed. I have been studying the tail section as speeds have been pushed up over the last three years with a supercharged SEO-540 on the nose. Confidence to push up the speeds depends on the design and build quality.

The designer published Vne on the Rocket is 240 KTAS (say 275 mph). In preparation for the Reno Air Races, I have completed power on descents in 2015 and 2016 for flutter testing (more than a few body parts were puckered up). Since I am here to write this note is a good thing. I took my 1998 Rocket (built in Bakersfield by three time RV builder) to 270 Kts true airspeed (310 mph) without adverse results. Stick forces get quite heavy but otherwise well mannered. Not recommended for RVs.

The conditions at Reno (density altitude, dirty air off racers and surface mechanical turbulence) still make me nervous on the flutter side, especially in the chute. Racing on Sunday with the Lancers and Glasairs, the true air speed for release in the chute got me out of my comfort zone, so pulled back the throttle until on the course.

Throttle UP! BB

[Mike S]

Bill, welcome aboard the good ship VAF.

Saw your plane at Reno, impressive stuff there.