TKATC - Report

[Toobuilder]

My Rocket has a standard issue RV-8 tail group and thanks to an unfortunate flying experience I don't want to expound on further, I believe there is significant flutter margin in a properly constructed tail. I have personally been well in excess of 270 knots (followed by a 6 G pull at gross weight) with no damage of any kind. Based on that experience as well as the number of Rockets flying with -8 tails, I think there is more to this than a "simple" overspeed.

[1001001]

Originally Posted by BillL

No repair, just rebuilt. Link on post #11. There was a self etch layer, hi build layer (sanded down) a yellow/gold layer, a red layer, then the clear coat. No mention of rudder weight in the report IIRC.

From the Accident Docket: "Witness Statements and interview Summaries":

Page 1 of I
Todd Gunther
Air Safety Investigator
Eastern Region
Date: September 21, 2013
Person Contacted: Amy Kelly (Spouse)
NTSB Accident Number: ERA13FA424
RECORD OF CONVERSATION
According to Mrs. Kelly, Her husband had the last annual inspection on the airplane done in
Texas. The plane was there for 7 days and while sitting on the ramp, the rudder was damaged by
the wind, prop blast, or jet blast. The rudder had a hole in it but her husband was able to fl y it
back to Cross Keys in March, and then built a whole new rudder. He then got a new gustlock, to
keep the rudder from being damaged again.
Page 1 of l
Todd Gunther
Air Safety Inves tigator
Eastern Region
Date: September 21,2013
Person Contacted: Butch H arold Delaney (Friend)
NTSB Accident Number: ERA13FA424
RECORD OF CONVERSATION
According to Mr. Delaney , the airplane had previously had its rudder damaged not too long ago,
and the pilot had duct taped the rudder, and flown it home. He then built a new rudder to replace
the damaged one.
This was his second accident. Both occurred in Hamilton Township .
During the first accident he had run t he airplane out of fuel.
Mr. Delaney also believed that the pilot was building another RV airplane when this accident
occurred.

[Steve Melton]

what does it take to loose a wing tip? has that ever happened before?

[ChiefPilot]

Originally Posted by Toobuilder

My Rocket has a standard issue RV-8 tail group and thanks to an unfortunate flying experience I don't want to expound on further, I believe there is significant flutter margin in a properly constructed tail. I have personally been well in excess of 270 knots (followed by a 6 G pull at gross weight) with no damage of any kind. Based on that experience as well as the number of Rockets flying with -8 tails, I think there is more to this than a "simple" overspeed.

One difference is your rudder has a single piece skin and isn't double-flush riveted like this one (and the Canadian -7 IIRC) was. Could that be significant?

[BillL]

Originally Posted by Toobuilder

My Rocket has a standard issue RV-8 tail group and thanks to an unfortunate flying experience I don't want to expound on further, I believe there is significant flutter margin in a properly constructed tail. I have personally been well in excess of 270 knots (followed by a 6 G pull at gross weight) with no damage of any kind. Based on that experience as well as the number of Rockets flying with -8 tails, I think there is more to this than a "simple" overspeed.

Originally Posted by ChiefPilot

One difference is your rudder has a single piece skin and isn't double-flush riveted like this one (and the Canadian -7 IIRC) was. Could that be significant?

Yes, and the 8 has a .020 skin, with smaller area and formed trailing edge with a counterweight. The failed rudder(s) is(are) .016 skins with the riveted TE. This "8" rudder is also known as the 7 "short" rudder shipped with very early 7 kits. Significant? good question indeed.

[glenn654]

The sequence of failures is the thing I am curious about.

If that first failure had not happened perhaps there may not have been other failures and a recovery may have been possible.

The lower third of the rudder was the first piece that apparently separated but I have doubts that it was the first part to fail.

Is there a way to know if the vertical failed first and then the left horizontal or vice versa?

Perhaps if it was possible to know where the first failure occurred it may have been possible to gain enough safety margin with a design modification to survive the incident.

An event like this will likely occur again someday so learning all we can about this may save someone else.

What is the g-load to failure the the vertical and horizontal?

Glenn Wilkinson

P.S. Just thinking out loud...I know about the overspeed, maybe abrupt control inputs etc.

[rvbuilder2002]

Originally Posted by glenn654

The lower third of the rudder was the first piece that apparently separated

I don't think there is any evidence to support this theory.
In fact I think there is specific evidence to suggest it was not.
There was extensive damage done to the fuselage side skins where the rudder cables exited the fuselage (not sure if it is visible in the photos posted in the docket, but it was clearly apparent in some of the photos I viewed during the initial investigation). The rudder cables sawed large holes in the skins before the cable attach points on the rudder horn finally failed (probably only took a few seconds). It could have been during these violent gyrations that strong vibrations were induced in the fuselage which caused a loss of the canopy and the wing tip.... but that is pure speculation... we will probably never know precisely what happened.

[Mike S]

There was a very good question asked in the final post of the rudder re-build thread--------------one that I have yet to see answered, if it is even possible to actually answer it.

http://www.vansairforce.com/communit...2&postcount=70

Last sentence is the one.........................

[rmartingt]

Originally Posted by jrs14855

He admitted very candidly and in some detail that he had been trying to teach himself rolls in the RV. he completely lost control and split s's , reaching near 300 m/h and a lot of G. ... I have seen this scenario far too many times.

I read a lot about people losing control and "falling out" during a roll... how does it typically happen?

[RV8iator]

Originally Posted by rmartingt

I read a lot about people losing control and "falling out" during a roll... how does it typically happen?

Im not being flippant here, but sadly enough it happens when people try to teach themselves aerobatics. Get some real trainng and learn how to do them correctly and also how to safely recover from a botched maneuver. Most peoples first reaction that have had no unusual attitude training is to just "pull up" when things go wrong. Upside down and fast that just may get you hurt.