"A" Model Tail Tiedown Ring Fairing

[Bob Axsom]

There are lots of variations on this but here is my cheap and dirty no fuselage fastener required tail tiedown ring fairing. I cut out a cylinder of 3/8" wood with a diameter forming a snug fit in the tiedown ring. I made the fairing out of 0.016 2024T3 with a spacer keel at the bottom & rear joint. Drilled staggered holes on the left and right side. Installed with two short wood screws and dimple washers and taped the fairing to fuselage joint. I saw a small increase in speed on the order of 0.15 kt.

Bob Axsom

[dan]

Man, why not just yank the rings out when you fly? I never have mine in unless the plane is chained to the ground. We go to all this trouble to make our RVs smooth -- imho a pair of tiedown rings in the slipstream (even with fairings) is like giving some of that away.

[osxuser]

But Dan, besides the measurable .12kt's you also get the added directional stability of those little surfaces sticking into the airstream...

[L.Adamson]

Originally Posted by dan

Man, why not just yank the rings out when you fly? I never have mine in unless the plane is chained to the ground. We go to all this trouble to make our RVs smooth -- imho a pair of tiedown rings in the slipstream (even with fairings) is like giving some of that away.

I was under the impression that it's the tail ring, which is a welded and permanent fixture for the RV6A's. The pic is too dark to tell.

L.Adamson

[dan]

Originally Posted by L.Adamson

I was under the impression that it's the tail ring, which is a welded and permanent fixture for the RV6A's. The pic is too dark to tell.

L.Adamson

Wow, I had no idea they were welded on the -6A. Learn something every day!

[Rick6a]

Originally Posted by dan

Wow, I had no idea they were welded on the -6A. Learn something every day!

Yea, my kit supplied tie down ring is perpetually for sale because I installed Orndorf's removable ring instead. When not in place, that hole becomes the world's largest drain hole. My hat is off to Bob for taking the time and effort to put a nice shade of lipstick on that pig.

Make me an offer.

[jcaplins]

For those still constructing:
How about using a tie down similar to whats on the cessna 182's, 206's wing strut(and probobly a load of other planes)? They are the spring loaded things that are recessed when not in use.

Sorry I don't have any pictures, but you know what i'm talking about. Right?


Jeff

[kentb]

I leave it in all the time. It works as a skid, in the event that I over flair on landing. You know that you got to keep the stick back.

I may build one of these my self. I haven't been building much lately.

Kent

[Bob Axsom]

As you are building if you give this some thought (on an RV-6A with the welded tiedown ring) almost anything you come up with to reduce the drag will work. This fairing is no exception and as has been stated earlier with a little forethought and tweaking it could be made to work as a trim tab for yaw.

When I flew in the Taylor 100 race recently I had the fairing in place when we arrived and it was time to tie down for the night. Since we were very early in the test flying of our plane we have been using the bent wire in the rudder stop and control horn to lock the rudder while the plane is tied down outside. As an aside however I found that during heavy gust loads the wire would pop out of the holes and allow the rudder to be banged around. There are many fixes for this but mine was to put the locks on both sides (yes two wires tied together with nylon wire bundle lacing tape with a red flag hanging from the looped string in the middle). Anyway back to the evolving idea. The resulting rudder locked situation with the double wires is rock solid and I observed that the triangular space formed by the wire on one side and the horn with its angled down vertical element formed an opening that could be used for the tail tiedown. I did use it for the three nights were stayed in Taylor with no problem. I am considering sawing off the ring and grinding the stub flush with the fuselage skin as the next step in my personal attack on this drag item.

Bob Axsom

[AlexPeterson]

I have never hit the tail tie down ring on my 6A during any flight ops, but I've wondered how far above the ground it is during a typical landing.

However, I was taxiing at Oshkosh to a camping area with an aft cg, and was going through a little dip right in the camping area and hit the ring as I was going up the other side. So, it does serve a function beyond just a tie down.

On my list is to machine something up which will have a recessed female thread so that I can remove the ring. Perhaps just threading in a streamlined skid for normal ops would be in order.