Posted for "rtitsworth" <rtitsworth@mindspring.com>:
Tom,
As stated by the others, a blunt gap (~1/8 or smaller), then covered with
gap tape and/or filled with silicone is the std approach. However, a few
builders have overlapped the wing and fairing (like a Columbia). Attached
is photo of Bryn Burr’s overlapped fairing (excuse the poor photo/lighting,
his looks really nice in person) and a Columbia (which is overlapped from
the factory).
A theoretical caution (no experience) for inserting the wings with an
overlapped fairing… The wings are relatively heavy and take a bit of
“wobbling” to get inserted and aligned in the fuselage spar pocket. It seems
perhaps if an overlapped fairing fit “tight”, that it could be damaged
and/or troublesome during the wing installation – and if it fit loose, it
might look poor. Furthermore, the spars insert essentially horizontal, but
the wing itself has an upward dihedral. So, building a tight fitting
overlapped fairing for the bottom would be impossible (due to the geometry).
This leaves you with a transition of some sort at the leading edge.
As a side note, when inserting the wings, try not to let the spar “rest” on
the lower faring as it slides/wobbles into the fuselage – the fairing is
generally not that strong (ask me how I know).
FYI, There are several methods for building/attaching the fairings. For
example, at the builders assist, we did mine by first cutting out the faring
rib and gluing it to the wing root (with foam spacers). We then inserted
the wings and built/bonded the fairing skins with the wings attached. When
completed, we pulled the wings off, breaking the foam spacers (see attached
photo). To get this approach to work, you need to start with a “very
straight” wing skin edge at the root. This is perhaps not as easy as it
sounds since the wing has both dihedral and camber. If you sand the root
edge “straight” with the wing in a horizontal position and then later raise
it to the proper dihedral, your “straight” line will become a “curve” when
viewed from the top or front. Thus, you need to make the wing root edge
“straight” with the wing in the proper orientation. I used a 6’ aluminum
bar with sandpaper glued to it to make the edge straight (at BL 25.5”)
Note: in the photo I have a black plastic electrical conduit that runs from
the front to the rear of the cabin “through the wing fairing”. This is a
modification/enhancement. It is not really part of the fairing, but
obviously needed to be installed before the fairings were done.
There also seems to be two schools of thought on whether you should do the
top or bottom fairing first. After pre-fitting each individually, I bonded
the top fairings first. Seems it could have also been done the other way
around. I also cut the bottom fairing into two parts (a front and back part
– seamed near the spar). This made getting it to fit much easier. The seam
is mostly covered by the gear leg fairing later anyway.
FYI, if all you have is the old manual, a new/pdf ES manual has been
available on the Lancair web site at
http://www.lancair.com/Main/builders_only/index.htm. However, it has
currently been removed for updating (???). Overall, it wasn’t really any
better than the old manual (in some cases it’s worse). However, it’s
helpful in selected areas. I’m using a combination of both. If you need a
copy of the prior electronic ES pdf manual, I could make a CD and send it to
you. Hopefully Lancair will have a new ES pdf uploaded soon.
Where are you located at?
Rick Titsworth
Detroit, Michigan
_____
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Tom
Wallace
Sent: Thursday, September 20, 2007 4:37 PM
To: lml@lancaironline.net
Subject: [LML] FW: Lancair ES Wing Fairings Fitting
Hello Group,
I am just starting to install the wing fairings and find the manual (mine is
1999 vintage) a little confusing. Seems like the manual directs you to end
up with a 1/8” gap between the fairing and the wing skins. I can’t find any
reference to filling this gap later. Seems to me that I’ve never seen a
plane with a 1/8” gap between the wing skin and fairing. I was thinking
that maybe the wing skin should slide into the fairing ¼ - ½ “ however that
type fit would probably abrade the paint on the wing area…????? Hope
someone can give me some guidance that’s been here already.
Any help on fitting the fairings to the wing skin would be greatly
appreciated.
Blue skies,
Tom Wallace
tlwcfii@yahoo.com
|