RV12 Rudder Cracks

[JOhn Ahearn]

Hi RV12 owners, and operators,
I'm interested to know if anyone has seen cracks like this on their RV12 rudder.
In the attached pictures you'll see two cracks - one each side at the bottom of the rudder - starting at trailing edge near the trim tab.

The trim tab is mounted to the rudder using double sided foam tape.

I suspect a lack of rigidity in the foam tape allows the trim tab to vibrate - which maybe caused the cracks to start and propagate.

There is also some impact damage around a rivet which could be the trigger point for the cracks to start.

The aircraft's first flight was in 2011. 675 hours.

Vans advised; "recommend full rudder placement. The rudder has been redesigned to help with this very issue by adding a Stub Spar and Trim Tab."

So in the meantime, I want to keep flying until a new rudder can be installed.

Has anyone had a similar experience?

I'm looking for a repair strategy. Drilling holes at the end of the cracks is an obvious answer. However, that solves the symptoms but not the cause.

I'm thinking about a patch that includes the trim tab, bonded and riveted in place. Any suggestions would be appreciated.

Thanks for any assistance.

Regards,
John

 

[scottmillhouse]

No experience with cracks on a 12. Was this plane by chance at Oshkosh 2022 when the big storm came through? The gust came from the rear and many rudders even with robust gust locks were damaged including my 7A. Looks like a result from similar force.

 

[GatorsR1]

John
I had to replace the rudder skin on my 12, of earlier design without the stub spar, due to a slight wrinkle (doink) on the trailing edge after an unfortunate bout with a hangar mates wingtip. The new kit, containing skin and stub spar, was very easy to install. Note that mine was unpainted.
Drill out rivets, remove skin, drill four holes in lower ribs for stub spar and then rivet on new spar, skin and trim tab.

 

[12vaitor]

It is interesting that Van's never published the Rev 1 for Section 7 or has issued a SL/SB to incorporate the stub spar. Seems unusual for a running production change to a structure to not make it to a SL/SB.

John Salak
RV-12 N896HS

 

[rvbuilder2002]

It is interesting that Van's never published the Rev 1 for Section 7 or has issued a SL/SB to incorporate the stub spar. Seems unusual for a running production change to a structure to not make it to a SL/SB.

John Salak
RV-12 N896HS

It falls under what many manufacturers refer to as a running change / product improvement.
Many of the legacy rudders are still doing fine but this minor change was done to help newly built rudders tolerate higher levels of abuse (damage doesn’t happen from flight loads… it is usually from banging around in the wind).

 

[Tony_T]

It falls under what many manufacturers refer to as a running change / product improvement.
Many of the legacy rudders are still doing fine but this minor change was done to help newly built rudders tolerate higher levels of abuse (damage doesn’t happen from flight loads… it is usually from banging around in the wind).

Even a slight breeze from aft will cause the rudder to bang against the stops. I carry and use a simple rudder lock that can't be forgotten and use it always even for a short stop for lunch.
I realize this does not answer the OP's question about what to do now, but a search of the forums for "rudder cracks" turned up a lot of posts with various temporary fixes. Even dr's 6 had/has a cracked rudder.