Cracks in Rudder Skin

[krhea]

2014 RV7- 537 hours, cracks in .016 skin of rudder at stiffener to spar.

Looking for possible avenues to repair these cracks.
1. Clear packing tape & stop drill-observation (gleaned from searching forum)
2. Click bond patch (gleaned from searching forum)
3. Patch over skin after stop drilling, IAW AC43-13-1B using Cherry N Rivets.
4. Rebuild Rudder using new skins stiffeners, ribs, wedge, spar; reuse FB parts, counterbalance, hardware.

It won’t bother me to put a patch on skin, not a perfect airplane, but doesn’t have any trim tabs and only weighs 1020# all up.

Maybe do #3 and then #4 later.

Have i missed anything?

Thanks

Keith Rhea
RV7
2021 Donation

 

[Fred.Stucklen]

Rudder Cracks

I had the same problem a year ago. It turns out Van's sells a rudder kit for the RV-7, so I bought one, put it together in a weekend, painted it, and replaced the old cracked rudder.
Be sure to glue (old Pro-Seal) the stiffeners to the inside of the skins to eliminate any possibility of getting cracks again...

2014 RV7- 537 hours, cracks in .016 skin of rudder at stiffener to spar.

Looking for possible avenues to repair these cracks.
1. Clear packing tape & stop drill-observation (gleaned from searching forum)
2. Click bond patch (gleaned from searching forum)
3. Patch over skin after stop drilling, IAW AC43-13-1B using Cherry N Rivets.
4. Rebuild Rudder using new skins stiffeners, ribs, wedge, spar; reuse FB parts, counterbalance, hardware.

It won’t bother me to put a patch on skin, not a perfect airplane, but doesn’t have any trim tabs and only weighs 1020# all up.

Maybe do #3 and then #4 later.

Have i missed anything?

Thanks

Keith Rhea
RV7
2021 Donation

 

[Ron RV8]

This was an elevator, but just an example of what cracks can lead to...

https://www.youtube.com/watch?v=ec-eWnCr7cQ

 

[Sam Buchanan]

This was an elevator, but just an example of what cracks can lead to...

https://www.youtube.com/watch?v=ec-eWnCr7cQ

Totally different scenario, the elevator had a cracked trailing edge.

The small (<1/2") cracks under discussion in this thread are at the end of stiffeners adjacent to the spar. The well-documented rudder cracks seen in numerous "thin-skinned" rudders over the past ~20 years have not resulted in safety of flight issues, just cardiac arrest in prospective buyers.

Any of the options explored by the original poster would be satisfactory in regard to airworthiness.

 

[AlexPeterson]

2014 RV7- 537 hours, cracks in .016 skin of rudder at stiffener to spar.

Looking for possible avenues to repair these cracks.
1. Clear packing tape & stop drill-observation (gleaned from searching forum)
2. Click bond patch (gleaned from searching forum)
3. Patch over skin after stop drilling, IAW AC43-13-1B using Cherry N Rivets.
4. Rebuild Rudder using new skins stiffeners, ribs, wedge, spar; reuse FB parts, counterbalance, hardware.

It won’t bother me to put a patch on skin, not a perfect airplane, but doesn’t have any trim tabs and only weighs 1020# all up.

Maybe do #3 and then #4 later.

Have i missed anything?

Thanks

Keith Rhea
RV7
2021 Donation

I stop drilled 3 cracks in 6A rudder at about 200 hours. Haven't done anything further for the next 1540 hours.

 

[plehrke]

2014 RV7- 537 hours, cracks in .016 skin of rudder at stiffener to spar.

I did not think the RV-7 kits ever had come with 0.016 skins on the rudder.

 

[Roy Thoma]

I also did not think any RV-7s had 0.016 skins.

Here is a picture of a patch on Ken Krueger’s -4. Un-rivet where the forward edge of the skins meet. Stop drill crack. Cover crack with patch that is riveted and prosealed in place. Before re-riveting front of skins make SURE to bend/massage the skins so they are not under tension.

Regards,

 

[patterson]

I stop drilled mine

2 - 1/2" cracks near the trailing edge.
650 hours and no issues. The addition of packing tape sounds like a good addition to this fix.

 

[krhea]

I just looked on the plans, did not measure and don't remember. Could be .020 skins.

 

[Laird]

That's almost EXACTLY the same patch I did on my .016 rudder skins in about 6 places after the stop drill holes continued to crack. I bonded my patches on, and used the the small pop rivets to replace the solid rivets I drilled out. Worked perfect. No more cracks.

I did recently build a new rudder w/ .020 skins, but that's just because I was Covid bored.

I also did not think any RV-7s had 0.016 skins.

Here is a picture of a patch on Ken Krueger’s -4. Un-rivet where the forward edge of the skins meet. Stop drill crack. Cover crack with patch that is riveted and prosealed in place. Before re-riveting front of skins make SURE to bend/massage the skins so they are not under tension.

Regards,