F704E Wing Center Section OPEN HOLES for Landing Gear on RV-7? Did Van make one Center Section?

[jackking123]

See Pictures: F704E which is the beefy fuselage bulkhead that the wing main spars slide in. There is a fwd and aft part of bulkhead. I am talking the fwd one.

14 open holes in upper spar cap and 8 open holes in lower spar cap. Mostly 1/4" holes but some 3/16".

I figure out that most of the holes are for the landing gear on a RV-7A. I am building RV-7.

There are x4 3/16" holes in upper spar cap (see picture) I can't find reference.

I would have liked to have a spar center section with no previsions for tricycle gear.
RV-7 spar center section with no 1/4" holes and just rivets.

Did YOUR RV-7 F704E come this way?

New photo · Thursday, Feb 12 📸

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New photo · Thursday, Feb 12 📸

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[rmartingt]

They get filled with bolts; the specific callouts can be tricky to find. The 1/4 holes are on Sheet 34 and the 3/16 holes are on Sheet 11 (they get a spacer as well and the bolt goes through both forward and aft parts).

They make a common center section for taildraggers and trigear because it keeps manufacturing costs down and gives you options (you get the center section before declaring your choice on the fuselage). And it also gives an ability (should you desire for some reason) to convert to a trigear later.

It's just a few bolts and they're easy to install.

 

[uk_figs]

+1 on the filling with bolts, there is also a Service Bulletin 12-08-14 on the wing attach bolts a as a number of cases were found where these bolts were not installed.
Also as noted check the drawings for installation as some bolts are inserted from the front and some washers are under the head versus the nut.
Figs

 

[jackking123]

OK confirmed. Thank you for taking the time. Just wanted to make sure. Called Van's Friday afternoon at 3pm PST and support was closed due to staff.

STILL CONFUSED about the four smaller 3/16" OPEN HOLES on the fwd F704A upper cap (F704E). They don't jive with anything or any drawing I can find. Not worried I can stuff bolts in there easy enough. I'll check that SB see if it's there.

They get filled with bolts; the specific callouts can be tricky to find. The 1/4 holes are on Sheet 34 and the 3/16 holes are on Sheet 11 (they get a spacer as well and the bolt goes through both forward and aft parts).

OK but only 2 bolts (spacer bolts) go through between the F704A halves, top cap, not including the 8 bolts attaching the spar to the F704A bulkhead, going through the full stack up both top and bottom caps (bars).

 

[wirejock]

I don't recall 3/16" holes. There are holes for the "A" model gear towers. I think there's a note on the plans or manual about them for the conventional models.

 

[mburch]

STILL CONFUSED about the four smaller 3/16" OPEN HOLES on the fwd F704A upper cap (F704E). They don't jive with anything or any drawing I can find.

Take a look at drawing 34, the correct bolts for those holes for taildraggers are shown there. When finished it looks like this:

 

[jackking123]

Take a look at drawing 34, the correct bolts for those holes for taildraggers are shown there. When finished it looks like this:

Yep I posted a snip of Dwg 34 in post #1. Got it. Thank you. That accounts for 10 of the 14 open holes in the upper chord. However I have 4 open 3/16 holes you show with rivets?

See Pic

New photo · Tuesday, Feb 17 📸

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I think they got left out. Trying to talk to Van's aircraft but Customer support is closed. I called today Tues Feb 17. Still has the same message, closed until Tues 16th (which is Monday). There is nothing they can do. I am convinced these are rivet holes that got left out. However they are too small for 3/16 rivets (#11 drill, the holes are #10). Weird. It is more of curiosity at this point.

I will either fill with 3/16" bolts or find some 3/16 rivets and drive them. I will have to get a 4x rivet gun. My 2X will not hack it.

 

[bobrv7taildragger]

Yep I posted a snip of Dwg 34 in post #1. Got it. Thank you. That accounts for 10 of the 14 open holes in the upper chord. However I have 4 open 3/16 holes you show with rivets?

See Pic

New photo · Tuesday, Feb 17 📸

Tap to view!

photos.app.goo.gl

I think they got left out. Trying to talk to Van's aircraft but Customer support is closed. I called today Tues Feb 17. Still has the same message, closed until Tues 16th (which is Monday). There is nothing they can do. I am convinced these are rivet holes that got left out. However they are too small for 3/16 rivets (#11 drill, the holes are #10). Weird. It is more of curiosity at this point.

I will either fill with 3/16" bolts or find some 3/16 rivets and drive them. I will have to get a 4x rivet gun. My 2X will not hack it.

left out...mine are filled with factory rivets....only the bolt holes are open. to clarify....only AN bolt holes are left open and yes bolts are set in these holes. one thing I found out...put the washers on "backwards" that is with the rounded edge to the aluminum....the sharper edge of the washers gouge the aluminum and I do this everywhere now after learning the lesson. against chromoly don't worry.

from the manual.
Main wing spar construction uses 3/16 rivets, which require a very high setting pressure, necessitating a heavy-duty rivet gun or a
fairly large rivet squeezer. RV kits have pre-assembled spars so builders do not have to set 3/16 rivets"

I would contact Vans about this. setting those rivets needs a 3/16" snap and a 4X gun. you should not have to buy those so vans will either replace it or sort out getting those rivets set.

 

[jackking123]

left out...mine are filled with factory rivets....only the bolt holes are open. to clarify....only AN bolt holes are left open and yes bolts are set in these holes. one thing I found out...put the washers on "backwards" that is with the rounded edge to the aluminum....the sharper edge of the washers gouge the aluminum and I do this everywhere now after learning the lesson. against chromoly don't worry.

from the manual.
Main wing spar construction uses 3/16 rivets, which require a very high setting pressure, necessitating a heavy-duty rivet gun or a
fairly large rivet squeezer. RV kits have pre-assembled spars so builders do not have to set 3/16 rivets"

I would contact Vans about this. setting those rivets needs a 3/16" snap and a 4X gun. you should not have to buy those so vans will either replace it or sort out getting those rivets set.

Thanks for the confirmation.
I did talk to them and they said put a AN3's in the holes.
For me to put in rivets they were not sized for rivet, but AN3. So I would have to ream...
I might do this if I can round up a X4 rivet gun. Already have long 3/16 button head AN rivets.
Bottom line mystery solved thanks to FAB community.
This is an older kit. I'm sure they sorted it out on later kits and Van said this is possible.
I understand one size fits all -7 and -7A wing/center section. Makes sense. So bolts it is.

PS Good tip on washer.