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Fuselage inspection Hole

MS1095

Well Known Member
The plans show one hole on the left side of the fusealgae between the last two bulkheads in the tail. I have seen flying airplanes with one hole and sometimes a hole on both sides. Does anybody have a valid a to put one on both sides, or should I stick to just one?
 
The plans show one hole on the left side of the fusealgae between the last two bulkheads in the tail. I have seen flying airplanes with one hole and sometimes a hole on both sides. Does anybody have a valid a to put one on both sides, or should I stick to just one?

The -6 has one on each side, as do all of the subsequent models. I think two access points are handy back there.
 
My -4 has an inspection hole on both sides. One good reason I can think of for having access to both sides is installing the bolt for the elevator pushrod rod end to elevator horn connection. Without an access hole on both sides, it would be VERY difficult to get a wrench on the opposite side nut or bold head.

I guess your alternative would be climbing head first down the fuse to do that job, which I've done. 6' and 215#, it's not fun...
 
Two Inspection Holes

I can tell you from experience that trying to get both hands in at the same time to do the elevator bell crank hook up is extremely challenging with only one opening available.

All subsequent airplanes I built, I put in the second one, and was always glad I did.

YMMV

HFS
 
I saw a 7 last fall where the guy has done one better and had put a lexan window in each of those panel covers. You could see all the way thru the tail and look at that linkage thru the window on every preflight
 
Recessed vs non-recessed cover

On the plans for the -6A (dwg 46) the opening hole is 2.5" x 3.25" and then it looks like there is a doubler ring so that the inspection cover will sit flush with the skin.

I read a post that some builders have done away with the flush mounting ring and have just surface mounted the cover plate. The advantage is that the access hole will be bigger.

What are your thoughts on flush mounting versus surface mounting the inspection cover plate?
 
one hole

My RV4 has just one hole. I was able to do all the hookups without any trouble. A hole on each side would have made it easier, of course, but no real trouble with one hole. I'm not flying yet, but the a/w inspection is next week.
 
On my -6 I joggled the opening like the stamped skins on the -7. That gave me flush cover plates without a doubler and allowed for a slightly larger opening for my fat hands.
 
Both sides

The plans show one hole on the left side of the fusealgae between the last two bulkheads in the tail. I have seen flying airplanes with one hole and sometimes a hole on both sides. Does anybody have a valid a to put one on both sides, or should I stick to just one?

I have them on both sides but made a big safety enhancement by making one side clear plexiglass.
Important because I can now see the torque tube bolt to elevator during pre-flight.
Note: prior builder did not use the correct length bolt, and also used a nyloc nut.
Found that post full aerobatic flight!

Daddyman
 
I have them on both sides but made a big safety enhancement by making one side clear plexiglass. Important because I can now see the torque tube bolt to elevator during pre-flight.
Note: prior builder did not use the correct length bolt, and also used a nyloc nut.
Found that post full aerobatic flight!
Daddyman

Nyloc nut is perfectly acceptable here. The nut is torqued down on a rod-end bearing and not subject to rotation. If you replaced with a castellated nut, I hope that you torqued to the proper specification.
 
learn somthing every day

Nyloc nut is perfectly acceptable here. The nut is torqued down on a rod-end bearing and not subject to rotation. If you replaced with a castellated nut, I hope that you torqued to the proper specification.

Mel,
I did not know that. Thanks for the correction.
It would have been fine if 2 threads were showing past the nut, but there were none, and it was in fact finger-loose.
Fell off when I touched it.

Yep torqued, then inserted a cotter pin.

Daddyman
 
How did everyone make the 4in round cover plate? I cut it out on bandsaw and use a belt sander. It's close but not perfectly round, and it bothers me.
 
used simple tools

How did everyone make the 4in round cover plate? I cut it out on bandsaw and use a belt sander. It's close but not perfectly round, and it bothers me.

I used a hand held jig saw on 1/4" plexiglass. Made the holes using a plexiglass bit.
It took 2 tries before I was satisfied. Sanded on a disc sander. Beveled the edges to save on drag. Looks darn sweet.
Daddyman
 
My RV-4 fuselage came with two holes. The one on the right side an inch or two lower than the one on the left side.

The reinforcement "rings" are actually not rings. More like mount plates for the nut plates. They are cut top and bottom so you can get a hand in sideways through the cuts.

One hole could be enough if placed so that you can get a hand in and put in the bolt from the opposite side. But you'll have to use a long wrench and something to hold the wrench while tightening the nut. If you need to add washers it's even harder.

Finn
 
Easy enough with a single inspection hole, I have just done final fitting of the elevator push rod on my RV 3. It is certainly tight and patience is required, I used a small wooden wedge to slightly push apart the elevator horns then inserted a bolt about halfway to hold the pushrod aligned, then put a washer in place with a washer holding tool (ie 2 strips of 016 riveted together with a 3/16 hole cut out) then insert another bolt from other direction pushing the first bolt out. Repeat for another washer on the other side if required.

Have a magnet on hand to easily retrieve any dropped bolts, washers or nuts. Easy to torque with a long socket extension.

Russell
 
Square bolt in a round hole

I saw a builder who made a superb inspection hole by turning a piece of Lexan on a lathe to make it circular, then pressed a round clip to match. I don't have a lathe or a hydraulic press, so I made round holes and square clips.
 

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Both the -6A I had and the -8 I have now, neither of which I built, had an inspection hole on each side of the rear fuselage and each was covered with a clear piece of plexiglass or Lexan for easy inspection. So far I have never had to take one of the covers off to do any work back there.
 
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