Condition inspection squawks

I have an email into Van's support on this one but I thought I'd check the collective wisdom of VAF. I've run into some issues on my third annual condition inspection (approx. 200 hours on the airframe)

The first issue is the infamous elevator trailing edge cracking. I'm just going to rebuild the elevators with .020 skins and use this as an opportunity to add electric trim. No big problem there, just annoying.

The second issue I ran into is that the right hand main gear has a bit of play in it. If you push on the axle you can get fore and aft movement of about 1/16 to 1/8 inch. The bolt at the top of the gear leg that runs through the gear socket moves with the gear leg. Not sure what is to be done about this. Any suggestions?

The third problem I found was some cracking of the top wing skin just outboard of the wingwalk. The cracks run along the rear spar rivet line and radiate from 3 rivet holes. The cracks appear to have been caused by the skin flexing when an errant foot has missed the wing walk. Again, suggestions are appreciated.

The biggest cause of skin cracking at the rear-most rivets of elevator and rudder skins is the trailing edge radius being too large. The radius should be such that the skin lays against the spar in relaxed state before any riveting. My trailing edges are crack free (.016) after 13 years of flying.
Mel...DAR

RV squawks

My RV-3 had the same exact issue with the gear legs (at 10yo). When the plane was on it's jacks, you could wiggle the gear with little or no force about 1/2" at the end. The bolt moved with it.

In our case the bolt-whole in the mount had oblonged from all the gear-leg shimmy. We fixed this by welding-filling the whole. We re-drilled undersized and reamed out to a snug fit. I only flew the plane for another year after doing that, but for that year, it did the trick.

I hope this helps.

-Bruce

RV Squawks!

Scott it would be interesting to hear a little more about the type of flying you do and your aircraft set up.

Do you do much aerobatic flying (big numbers on the G meter)?
What kind of strip do you operate out of?
Engine size and prop type( one or two blades)?

I'm sure Mel is right about the Elevator trailing edge radius, particularly after 13 years!
Did you apply the RTF to the stiffeners?
Have you seen any cracks in the rudder?
Were the radius bends formed on the Rudder and the Elevator the same?

Randy Lervold did quite a lot of work regarding the .016" vs .020" skins and came to the conclusion that if they were formed properly and the RTF was applied there was little to worry about, I'll wait and see, I'm not ready for flying yet and I have .016" skins.

Now the cracks in the wing skins near the walk on reinforcement is a bit of a worry since I'd not heard of this one before!!

Just trying to reassure myself that 15 mins in every hour would be OK upsidedown................!

I used no RTV or sub-ribs in my elevators or rudder.
Mel...DAR

Condition Inspection Squawks

Funny you should inquire about condition inspection squawks. If you have followed this forum for any length then you might remember the broken weldmens I found on my aircraft last October on a Condition Inspection. Articles with pictures will be in both the EAA Sport Aviaition magazine and the IAC Sport Aerobatics magazine. I had hoped not to go this route but Van's was not interested in issuing a service bullitin on the pre 1984 RV4s. Roger Moore [email protected]

I can't answer many of the questions regarding the tail feathers because I didn't build them. I bought the kit from another builder. I have already ordered the fixin's for a new set of elevators with .020 skins and an electric trim kit. The cracking elevators is a fairly common problem so I'm not too concerned with them. Besides, they are easy enough to rebuild. Since I'll be building them this time I can pay more attention to what Mel suggests.

I don't do any aerobatics though I have been known to turn and bank agressively. I have thus far only flown from paved runways. The engine is an Aerosport O320-D2A with a two blade Catto prop and Landol harmonic balancer. No cracks in any of the other trailing edges.

My bigger concern is the cracking on the top wing skin and how to fix that. Also the gear wobble. Here's a link to the diagram I sent Van's.

Welds and age

FYI: It's standard practice for me, but be sure to check all the welds on your mount. Pay very close attention to the big corner weldments. They crack with bad lan... err age

-Bruce

Straight from the horse's mouth...

Here's Vans' answer to my email:

On 11 Feb 06, at 20:04, Scott wrote:

> Hello,
> I have a couple of concerns about some items that came up during my
> third annual condition inspection. Item number 1 is that some
> cracking has started to occur along the left wing top skin / rear spar
> rivet line. Cracks have formed around 3 rivets on the top skin just
> outboard of the reinforcing plate that you step on. I left my
> drawings at the hangar so I apologize for not having part numbers but
> I'm sure you know what I'm talking about. My assumption at this point
> is that this was caused by carless feet. My question is can this be
> repaired and how can it be repaired? Is replacing the inboard top
> skin my only option?

It's the only option to get rid of the cracks, but if you stop drill them
(don't drill into the spar though) it would be OK to leave them, and
they may not spread any further.

>
> Item number 2 involves the right hand main gear leg. When I had the
> wheel off today I noted that the axle can move fore and aft about 1/16
> - 1/8 inch. The bolt at the top of the gear leg seems to move with
> the gear leg. Is this a concern and if so what are my repair options?
>

It probably won't matter with that amount of movement, but it is likely
to get worse over time, sooner or later you will ned to fix it. You can
ream the hole out to 3/8, which will probably take care of it at this
stage by making the hole in the mount round again; it is most likely
slightly oval. Alternatively, you could weld a patch over the holes in
the mount and redo the hole to 5/16 and avoid enlarging it, if the
hole in the gear leg itself is still round.

Vans