UPGRADING YOUR GLASAIR I FUSELAGE
This is a follow-up article to the earlier article about the upgrading of the
Glasair one wing. Just as the G-I wing can be upgraded using the components and
ideas from later kits, so too can the fuselage.
One of the simplest and structurally beneficial additions is the addition of two
unidirectional stiffening bows used in each side of the Glasair II aircraft.
The first unidirectional bow reinforces the wing cutout area. This bow is
installed in the foam core area just above wing cutout. Installing this bow on
each side will eliminate the need for the 6 layer laminate fuselage to forward
wing stiffening angle (shown in the later sections of the G-I Final Assembly).
This wing cutout siffening bow can be fabricated in place and should be
approximately 3/4" wide in the middle and flare out at the ends.
The second bow is installed just below the cutout for the gull wing doors. This
stiffens the fuselage to compensate for the strength lost cutting the doors from
the fuselage shell. This second bow is approximately 3/4" in width and 60" in
length and is centered under the door cutout. This bow can be fabricated in
place by cutting an appropriate sized channel in the inner skin and foam core.
The channel is then filled with successive layers of unidirectional cloth until
the channel is filled. The inner skins are then patched with a 2-layer
bidirectional laminate layer.
Another fuselage upgrade that has been very popular with G-I builders is the
bonding on of the wing to body fairings. The techniques used on the later
Glasair kits can easily be adapted. The bonded on fairings will stiffen the
fuselage as well as fit the wing and fuselage more tightly.
Some of the other G-II features, which could be incorporated, but with more
effort, would be to fabricate a cowling attach flange on the forward end of the
fuselage. The present instructions have the builder use pieces of aluminum angle
bolted to the forward side of the firewall. Creating a fiberglass firewall
attach flange before installing the firewall will create a stronger more durable
cowling attach method.
Those builders installing the firebarrier upgrade per Addendum 15 can take
advantage of the more recent methods of attaching the forward aluminum
firebarrier closeout sheet.
Several builders have asked about using the latest gull wing door latch and
hinges on the G-I. The upper fuselage contour is slightly different which makes
use of these hinges impractical. The latch kits have been installed but this
takes a significant amount of work enlarging the door frame to accommodate the
required installation dimensions of the newest style overcenter door latch
parts.
Several builders have also asked about using the screw and nutplate method of
attaching the fuselage (underwing) belly panel rather than the present piano
hinge attachment. This has not proved practical since the fore and aft size of
this G-I belly panel is shorter than the later aircraft. Because of this shorter
size installing a flange (necessary to mount nutplates) on the fuselage creates
a shortened opening making installation of the wing in the fuselage impossible.
Another G-II feature which has been very popular is the addition of the Dorsal
Fin. This simple fiberglass part is easy to install and gives the airplane a bit
more of the P-51 look.
This is likely not a comprehensive list of upgrades. The old company Stoddard
Hamilton Aircraft had a separate Options Catalog Addendum just for the Glasair
I. Although copies of this catalog are no longer generally available we can make
copies of pages that have items G-I builders may be interested in. If you have
questions about anything you have just read feel free to contact me here at
NewGlasair during Tech Support hours (1-3 PM, Tuesday, Wednesday, Thursday). My
phone number here is (360) 435-8533 Ext. 230