RV7 plan horizontal stabilizer plan 3

I have a completed RV7 and I understand that the new Plan 3 depicts a different construction method for the front spar to alleviate the stress relief notch. Would someone email me a copy of the most current sheet 3 if it is permissible. Thanks [email protected]

On Van’s Site

Hi,

Is this what you need? Found under Service Bulletins on Van’s.

https://www.vansaircraft.com/service-information-and-revisions/sb-14-01-31/

Study it well. It is a very complicated area that is easily messed up.

Thanks I received a copy of the current plan 3 and it shows where the spar web edge has been removed at the bend line. I believe this would relieve stress at the point where cracks have occurred. There is no question that the mod obviously adds strength in this area. It would appear that there remains confidence in the original design as the SB only suggest continued inspection if no crack appears.

I would agree that the repair is very complicated and I am afraid more damage may occur completing the repair than continued monitoring. This area of the spar web appears to be .032 with significant additional support at this position. The SB also suggest that if the crack terminates at the rivet hole, no further action is required to terminate the crack. If there is no further movement it would appear that the stress has been relived.

I am still trying to determine what is the source of the stress at this area. It would appear that the point where the stabilizer is connected to the fuselage would be the point of the greatest stress.

Stress source

I suspect (speculate) that the source of the stress may be from the vertical stabilizer front spar, as it is attached to the horizontal stabilizer forward spar. Sideward forces on the vertical stabilizer would partly transfer through that location to the fuselage. It seems like an odd location for cracks to potentially occur though.
Cheers
Paul.

Van's S.B: 14-01-31

Hi,

You are correct when you say that the Service Bulletin requires ongoing inspection if it has not been incorporated.

You are also correct when you say that the Service Bulletin is difficult to incorporate and that you may induce further problems if you carry it out. That is why Van's only advise to accomplish it if you find cracks during your ongoing inspections.

It also states that if the Empennage Kit was a match hole version as delivered from Van's the modification is not applicable as the intent was incorporated by Van's. However, I would still perform the ongoing inspections.

The Service Bulletin also covers a number of other RV versions and possibly the cracking is probably more prevalent in other older variants.

Cheers,

griffg said:

It also states that if the Empennage Kit was a match hole version as delivered from Van's the modification is not applicable as the intent was incorporated by Van's. However, I would still perform the ongoing inspections.

The Service Bulletin also covers a number of other RV versions and possibly the cracking is probably more prevalent in other older variants.

Cheers,

Click to expand...

Help me understand your comment. I believe what you are saying is the modification within the SB is not applicable to match-hole kits. I believe you have mis-read step 6 in the instructions on page 3. The HS-710 re-inforcement angle does not need further inspection (once removed) because it is a matched-hole kit.

But the SB modification does apply to matched-hole kits if cracks are found or the owner/builder wants to incorporate the modification.

Perhaps I mis-read your post.

Mod applicability

Hi Scot,

I have had cause to read the Service Bulletin again and you are correct that the "not applicable to match hole kits" only applies to the HS-710 Reinforcing Angle.

My apologies to everybody if I have caused any confusion.

Cheers,