Possible edge distance issue on F-710B

Hi everyone,

I'm getting ready to install my horizontal stabilizer on the fuselage.
Before drilling the holes I re-checked the plans and instructions and realized that I may have an edge distance issue on the F-710B angle that is part of the support of the forward spar of the horizontal stab.

Please refer to the picture below and Van's drawing 27A.
This picture is taken from inside the aft fuselage, facing aft and looking up:



Same issue on the other side!

I've sent an email to the Mothership, but I'll get faster replies here...

I think when I fabricated the F-710B angle I cut at a 90? angle, when I should have cut with a slight angle so the edge of the angle would be parralel to the fuselage longeron.

What do you think??

If I have to replace the F-710B angle i involves drilling out about 60 rivets to remove the F-714 aft deck.

Thank you for your comments.

Alain.

Wait for the Vans factory reply.

IIRC there is a 'semi-standard' doubler fix for that problem.

That is a reasonably common issue, even with the QB fuselage. Talk to Van's first, but they will probably suggest a doubler with longer bolts as a fix. Drilling off the aft deck to replace the angle isn't that difficult either, it only takes an hour or so..
Cheers,
Hugh.

How to fix it.

I called Vans yesterday:

All the "stress" in this area is vertical, not sideways.
Edge distance is still necessary on F-710B but not as critical as in other areas, so 1/2D edge distance would be acceptable as long as the hole is dead center on the fuselage longeron.
If less than 1/2D on F-710B than:

Solution 1: drill out all rivets for the F-714 aft deck and the F-710B angle, re-fabricate the F-710B and re-rivet everything together.

Solution 2: fabricate a doubler, drill out the 4 rivets holding F-710B to the aft deck, re-rivet F-710B and doubler and drill holes for H-stab trough all the layers.

For my own peace of mind I think I'll do solution 1... Longer but better, as long as I don't mess up drilling out about 60 rivets!

According to Vans support this a common problem...

Thank you for the replies.

Alain.

I remember this issue when I built my fuse, fortunately I came across someone's build sit that identified this. on mine I remember custom fitting this angle, can't thank this site, and other peoples build sites enough, it has saved me lots of mistake and money. but even then.

Newbie question here...

First time builder about to order the -7 empennage. When issues like this come to the attention of Vans as a frequent occurrence, do they change the plans/instructions in a timely manner so that others don't make the same mistake? Sure would be nice if they kept an official list of gotchas published, in lieu of changing the instructions.

Just imagining myself referencing this forum before every single step to keep from screwing up (although I know full well I will definitely make my share of mistakes)

RV74ME said:

Newbie question here...

First time builder about to order the -7 empennage. When issues like this come to the attention of Vans as a frequent occurrence, do they change the plans/instructions in a timely manner so that others don't make the same mistake? Sure would be nice if they kept an official list of gotchas published, in lieu of changing the instructions.

Just imagining myself referencing this forum before every single step to keep from screwing up (although I know full well I will definitely make my share of mistakes)

Click to expand...

NO NO NO You might contact wirejock here on VAF, he as been posting 7 issues since day one (it seems) and maybe he has a txt he can send to you.

One thing to learn, check -double check, and then think. Now - think 3 steps ahead (or 5 on the canopy) and see what consequences things will have. This is part of the learning and second guessing process. It takes more time than building. Or just forge ahead, and accept in advance to redo the mistakes, probably faster. No one is perfect.

EDIT: My first tip - get a small neodymium magnet and use it to mark the end of the back rivet plate is so you won't pull the trigger on a rivet without the plate behind it. It might just be the most often issue on the emp.