Tailwheel spring

A friend of mine owns a beautiful RV-7 which he purchased already built.

The other day, he kind of botched a landing and came down pretty hard on the tailwheel. The stinger flexed and the tailwheel fork attach nut struck the bottom of his rudder. It hit hard enough to dislodge his tail strobe/position light, although I think the integrity of that particular attachment was a bit questionable. I shot up to take a look at it for him yesterday.

Other than a bit of a mashing of the paint where the tailwheel yolk attach bolt struck, there appears to be no damage anywhere.

All hinges/rod end bearings for the rudder are perfect, show no signs of cracking or bending, no loose or popped rivets, jam nuts are tight, everything seems fine.

Inspection of the stinger attach fittings seems to be damage free. No loose or broken rivets, no wrinkles in the skin, nothing.

While all seems fine, the bottom of the bottom rudder fiberglass part rubs against the stinger with the airplane in the normal stance. (weight on the tailwheel) It is unnoticeable while operating the rudder normally, but the stinger is actually against the fiberglass. Cant slide a piece of paper between!

I'm a bit flummoxed. As he is not the builder, and as neither one of us actually ever looked at that fit prior, we have no idea if it was like this before. While the length of the stinger does not appear to be bent, it seems very unlikely that even if it did bend, that the bend would happen right at the rear attach fitting. I recall some recent discussion regarding this clearance but am unable to find the thread. Has anyone seen this?

Thanks,
Jesse

Another look

I purchased my RV8 flying, so I can't vouch for the entire history of the aircraft. But I'm pretty sure I've never had a landing event that could have bent anything. Anyway I have always been a bit concerned about the clearance between the tailwheel spring and the bottom rudder fairing. I doubt I could get more than a credit card thickness in between the two.

Have seen damage to the rudder bottom similar without damage to the spring. Adding that many RV-7s have had to modify the front end of the bottom cap to clear the spring. If you look around you will how it was done. Some made it flat for the few front inches or just fit the cap closer the rudder when installing.

The tail spring and the sock it inserts into should be parallel when the weight is removed from the tail wheel.
Even though the tail spring is tapered, you should be able to check for bend with a straight edge held against the bottom of the mount.

Additionally, if it has been rubbing since first flight, I would think that the paint would be rubbed through by now. It could be checked that way if you are willing to remove the rudder.

Tail wheel spring

My 15 year young RV7 is somewhat heavy and has had many less than perfect tail first landings. Some are after a well loaded cross country trips with minimal fuel and aft CG. My rudder bottom has been touched up a number of times.

I thought the spring was straight, with a strait edge lined up with it, looked ok. But I pulled the spring out and rolled it across the flat floor. Certainly bent quite a bit and holes were drilled such that I couldn't just flip it over. Sent it back to mfgr to have it straightened, asked for a bit of reverse bend while they had it in the press.

Worked out great. More clearance and no rudder contact since. Of course my landings are improving as well.

PS: Check out the aft fuselage sides as well. -7s have a tendency to have a bend in the skins due to tail wheel loads. Discussion on the VAF led me to add reinforcing angle pieces below the access plate and double check all the bolts and rivets on bulkheads and weldments.

Lesson: be gentle on the tail wheel.

I've been trying to search for any threads discussing the RV-7 aft fuselage bending and ideas for reinforcing. No luck finding anything. Can anybody post link(s) here to help out? Thanks.

Tail wheel spring

It wasn't really that the fuselage was bending, just a slight bow in the skins on either side between the bulkheads. Take a look at -7s whenever you run across one and it is not uncommon to see this. I ended up flush riveting some pieces of angle between the bulkheads on either side. Am considering putting in a double layer of access cover perhaps with some more screws/nut plates. I found some old threads about this quite a while back and followed suggestions. Worked well for me, but I am making better landings and my grandson is now too big for the "backseat" anyway.