Wing Attach Fittings Paranoia

[Eric Fogelin]

The Elite is coming along nicely. I'm working on the right
wing after knocking down a wall in my crowded workshop.
But am having an attack of bolt hole edge distance
paranoia.

Things have gone well and I am now fitting the front and
rear spar fittings. These are the fittings that attach the
wing to the fuselage (W-119 and W-124 which I believe are
the same part numbers on the Rebel).

The front and rear spars are pre-punched for placing
the spar fittings. The pre-punched holes at the spar root
have the normal 5/16" edge distance found on most parts.
However, these holes get drilled and reamed for either
AN3 or AN4 bolts which would require at least 3/8" edge
distance (for AN3 bolts).

As these fittings seem *really* small (for attaching something
as important as the wing). And the number of bolts doing
the attaching also seems small, I'm making every attempt
to keep tolerances tight.

The factory parts all seem to be manufactured correctly. I know
there are extra doublers in this area. But why is edge distance
not a problem here, when it seems like you'd *really* like that
extra metal?

Also, the construction in this area does not seem to allow
inspection or replacement of the bolts holding the front spar
fitting. As I'll be on floats, I'd like to be able to inspect
and replace all bolts as they can corrode over time from
water and abuse (especially salt water). Am I misreading
the manual or are these bolts all torque 'em and forget 'em?

I checked Wray's online manual and the Elite looks almost
identical to the Rebel in this area so words of wisdom and
comfort will help me sleep better.

Thanks,

Eric Fogelin
Elite 645
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[Eric Fogelin]

Thanks, Wayne. I'm feeling better already.

But just to follow-up. How about the edge distance problem?
On the Rebel, is the Root Rib Attach Bracket (W-161) flush
with the root end of the front spar? If yes, then the Rebel
doesn't have an edge distance problem as the W-119 Front
Spar Fitting Attachment will be bolted 15/32" back from the
root end of the front spar. My W-161 bracket overhangs
the root end due to the 5/16" pre-punched holes in the front
spar used to align W-161.

I've got email into Murphy on what, if any, differences there
are in this area between the Elite and Rebel. They seem
almost identical, but something seems wrong.

Your insight and experience has been a great aspect of
this internet group.

Thanks,

Eric

----------
From: Wayne G. O'Shea[SMTP:oifa@irishfield.on.ca]
Reply To: murphy-rebel@dcsol.com
Sent: Thursday, January 27, 2000 5:29 AM
To: Murphy Rebel Builders List
Subject: Re: Wing Attach Fittings Paranoia

Eric, Torque 'em and Forget 'em, just like a Cessna or any other! Coat them
with epoxy chromate before installing so the water can't get in there! I
have fixed some pretty good wrecks (if you can call a wreck good). The wing
fittings have always been in perfect condition (after the fall) and I had
one where the cabin was narrowed at the rear attach fitting by 8", after the
wing tip dug into the ground. The wing fittings were just fine, although the
compression of all three torque tubes jamming together cause the opposite
wing to be damaged inside also. The Rebel that went in the lake and
cartwheeled bent the right wing up like a boomerang, but all fittings were
left like new! In most aspects of flight there is a compression load on the
attach fittings and not tension. Hope this lets you sleep at night now,
Wayne

-----Original Message-----
From: Eric Fogelin <ericfo@whidbey.com>
To: 'murphy-rebel@dcsol.com' <murphy-rebel@dcsol.com>
Date: Thursday, January 27, 2000 1:09 AM
Subject: Wing Attach Fittings Paranoia

The Elite is coming along nicely. I'm working on the right
wing after knocking down a wall in my crowded workshop.
But am having an attack of bolt hole edge distance
paranoia.

Things have gone well and I am now fitting the front and
rear spar fittings. These are the fittings that attach the
wing to the fuselage (W-119 and W-124 which I believe are
the same part numbers on the Rebel).

The front and rear spars are pre-punched for placing
the spar fittings. The pre-punched holes at the spar root
have the normal 5/16" edge distance found on most parts.
However, these holes get drilled and reamed for either
AN3 or AN4 bolts which would require at least 3/8" edge
distance (for AN3 bolts).

As these fittings seem *really* small (for attaching something
as important as the wing). And the number of bolts doing
the attaching also seems small, I'm making every attempt
to keep tolerances tight.

The factory parts all seem to be manufactured correctly. I know
there are extra doublers in this area. But why is edge distance
not a problem here, when it seems like you'd *really* like that
extra metal?

Also, the construction in this area does not seem to allow
inspection or replacement of the bolts holding the front spar
fitting. As I'll be on floats, I'd like to be able to inspect
and replace all bolts as they can corrode over time from
water and abuse (especially salt water). Am I misreading
the manual or are these bolts all torque 'em and forget 'em?

I checked Wray's online manual and the Elite looks almost
identical to the Rebel in this area so words of wisdom and
comfort will help me sleep better.

Thanks,

Eric Fogelin
Elite 645
*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*




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[Wayne G. O'Shea]

--------------------------------------------------------------------------
Your following message has been delivered to the 147 members of
the list murphy-rebel@dcsol.com at 08:33:03 on 27 Jan 2000.
--------------------------------------------------------------------------


Eric, Torque 'em and Forget 'em, just like a Cessna or any other! Coat them
with epoxy chromate before installing so the water can't get in there! I
have fixed some pretty good wrecks (if you can call a wreck good). The wing
fittings have always been in perfect condition (after the fall) and I had
one where the cabin was narrowed at the rear attach fitting by 8", after the
wing tip dug into the ground. The wing fittings were just fine, although the
compression of all three torque tubes jamming together cause the opposite
wing to be damaged inside also. The Rebel that went in the lake and
cartwheeled bent the right wing up like a boomerang, but all fittings were
left like new! In most aspects of flight there is a compression load on the
attach fittings and not tension. Hope this lets you sleep at night now,
Wayne

-----Original Message-----
From: Eric Fogelin <ericfo@whidbey.com>
To: 'murphy-rebel@dcsol.com' <murphy-rebel@dcsol.com>
Date: Thursday, January 27, 2000 1:09 AM
Subject: Wing Attach Fittings Paranoia

The Elite is coming along nicely. I'm working on the right
wing after knocking down a wall in my crowded workshop.
But am having an attack of bolt hole edge distance
paranoia.

Things have gone well and I am now fitting the front and
rear spar fittings. These are the fittings that attach the
wing to the fuselage (W-119 and W-124 which I believe are
the same part numbers on the Rebel).

The front and rear spars are pre-punched for placing
the spar fittings. The pre-punched holes at the spar root
have the normal 5/16" edge distance found on most parts.
However, these holes get drilled and reamed for either
AN3 or AN4 bolts which would require at least 3/8" edge
distance (for AN3 bolts).

As these fittings seem *really* small (for attaching something
as important as the wing). And the number of bolts doing
the attaching also seems small, I'm making every attempt
to keep tolerances tight.

The factory parts all seem to be manufactured correctly. I know
there are extra doublers in this area. But why is edge distance
not a problem here, when it seems like you'd *really* like that
extra metal?

Also, the construction in this area does not seem to allow
inspection or replacement of the bolts holding the front spar
fitting. As I'll be on floats, I'd like to be able to inspect
and replace all bolts as they can corrode over time from
water and abuse (especially salt water). Am I misreading
the manual or are these bolts all torque 'em and forget 'em?

I checked Wray's online manual and the Elite looks almost
identical to the Rebel in this area so words of wisdom and
comfort will help me sleep better.

Thanks,

Eric Fogelin
Elite 645
*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*




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[Wayne G. O'Shea]

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Your following message has been delivered to the 147 members of
the list murphy-rebel@dcsol.com at 17:04:41 on 27 Jan 2000.
--------------------------------------------------------------------------


Eric,
I have a "spare" Rebel wing out in the hanger and will have a look at it
later tonight (it's -39c so not to keen tonight) or in the morning, to check
the edge distance. I am working on a SR wing set right now in the shop and
it has very minimal E.D. for the two bolts that hold the Root rib to the
front spar. I know Murphy load tests their wings before offering to the
market (unlike some others) so I wouldn't worry too much about it. The only
thing to check is that when you put the ribs in place, is the distance
between each rib set equal (for and aft) all the way along, to prove the
predrilled holes are in the right location and that you didn't get a bad
front spar.

Blue skies,
Wayne G. O'Shea
www.irishfield.on.ca

-----Original Message-----
From: Eric Fogelin <ericfo@whidbey.com>
To: 'murphy-rebel@dcsol.com' <murphy-rebel@dcsol.com>
Date: Thursday, January 27, 2000 2:24 PM
Subject: RE: Wing Attach Fittings Paranoia

Thanks, Wayne. I'm feeling better already.

But just to follow-up. How about the edge distance problem?
On the Rebel, is the Root Rib Attach Bracket (W-161) flush
with the root end of the front spar? If yes, then the Rebel
doesn't have an edge distance problem as the W-119 Front
Spar Fitting Attachment will be bolted 15/32" back from the
root end of the front spar. My W-161 bracket overhangs
the root end due to the 5/16" pre-punched holes in the front
spar used to align W-161.

I've got email into Murphy on what, if any, differences there
are in this area between the Elite and Rebel. They seem
almost identical, but something seems wrong.

Your insight and experience has been a great aspect of
this internet group.

Thanks,

Eric

----------
From: Wayne G. O'Shea[SMTP:oifa@irishfield.on.ca]
Reply To: murphy-rebel@dcsol.com
Sent: Thursday, January 27, 2000 5:29 AM
To: Murphy Rebel Builders List
Subject: Re: Wing Attach Fittings Paranoia

Eric, Torque 'em and Forget 'em, just like a Cessna or any other! Coat them
with epoxy chromate before installing so the water can't get in there! I
have fixed some pretty good wrecks (if you can call a wreck good). The wing
fittings have always been in perfect condition (after the fall) and I had
one where the cabin was narrowed at the rear attach fitting by 8", after

the

wing tip dug into the ground. The wing fittings were just fine, although

the

compression of all three torque tubes jamming together cause the opposite
wing to be damaged inside also. The Rebel that went in the lake and
cartwheeled bent the right wing up like a boomerang, but all fittings were
left like new! In most aspects of flight there is a compression load on the
attach fittings and not tension. Hope this lets you sleep at night now,
Wayne

-----Original Message-----
From: Eric Fogelin <ericfo@whidbey.com>
To: 'murphy-rebel@dcsol.com' <murphy-rebel@dcsol.com>
Date: Thursday, January 27, 2000 1:09 AM
Subject: Wing Attach Fittings Paranoia

The Elite is coming along nicely. I'm working on the right
wing after knocking down a wall in my crowded workshop.
But am having an attack of bolt hole edge distance
paranoia.

Things have gone well and I am now fitting the front and
rear spar fittings. These are the fittings that attach the
wing to the fuselage (W-119 and W-124 which I believe are
the same part numbers on the Rebel).

The front and rear spars are pre-punched for placing
the spar fittings. The pre-punched holes at the spar root
have the normal 5/16" edge distance found on most parts.
However, these holes get drilled and reamed for either
AN3 or AN4 bolts which would require at least 3/8" edge
distance (for AN3 bolts).

As these fittings seem *really* small (for attaching something
as important as the wing). And the number of bolts doing
the attaching also seems small, I'm making every attempt
to keep tolerances tight.

The factory parts all seem to be manufactured correctly. I know
there are extra doublers in this area. But why is edge distance
not a problem here, when it seems like you'd *really* like that
extra metal?

Also, the construction in this area does not seem to allow
inspection or replacement of the bolts holding the front spar
fitting. As I'll be on floats, I'd like to be able to inspect
and replace all bolts as they can corrode over time from
water and abuse (especially salt water). Am I misreading
the manual or are these bolts all torque 'em and forget 'em?

I checked Wray's online manual and the Elite looks almost
identical to the Rebel in this area so words of wisdom and
comfort will help me sleep better.

Thanks,

Eric Fogelin
Elite 645
*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

*----------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*----------------------------------------------------*

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between builders and owners of Murphy Rebel aircraft.
Archives located at:
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[klehman]

Eric Fogelin wrote:

But just to follow-up. How about the edge distance problem?
On the Rebel, is the Root Rib Attach Bracket (W-161) flush
with the root end of the front spar? If yes, then the Rebel
doesn't have an edge distance problem as the W-119 Front
Spar Fitting Attachment will be bolted 15/32" back from the
root end of the front spar. My W-161 bracket overhangs
the root end due to the 5/16" pre-punched holes in the front
spar used to align W-161.

Eric

FWIW on my Rebel the w161 overlaps the leading edge spar (inboard) on both
wings.
On the right wing I just barely have 1/2" edge distance on the leading edge spar
for the AN4 bolts. The left wing has quite a bit less. In addition to Wayne's
comments, I think maybe the spar doublers (.040 and .050?) reduce the need for
the normal edge distance.

As far as corrosion goes, I chromated over the entire bolt. I asked MAM about an
inspection/access plate and they said no, which I guess is not surprising in
this area. I believe I had to insert the bolts with the head forward to clear
the wing skin so there would be no way to remove them anyway.

There is a similar situation at the rear spar where the width of the flange on
the root rib is not sufficient for the normal edge distance. I am sure that MAM
has designed for this as well however.

cheers
Ken

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