start the plane from one single point.
The front canopy was designed to be remova-
ble but is normally not touched except to
remove the batteries and charge them. The
short nose makes it a breeze to access these
batteries and make it very easy to charge
them out of the plane for maximum safety.
The full depth cockpit tub is inserted into the
canopy frame and the whole unit is removed
as a block. Enough room is available in front
of the cockpit tub to fit a GPS unit and pitot
sensor board or ASSI board.
I managed to get my hands on the drawings
of the Martin Baker Mk5 ejection seat and that
was the occasion to CAD design a super
scale cockpit. Using the pictures of the seat,side panels, front instrument panel, I went full
scale and included every screw, switch, dial
and knob available. These components are
either 3D printed in-house on my SLA laser
printers or available as a simpler kit of cast
resin panels. The cockpit tub allows to place
all these components as well as a full height
ejection seat and allows for a very easy
access to the nose section once the canopy/
tub assembly is removed.
All of this CFD study, iterations tests and trou-
bleshooting took about 1 year before I would
be confident enough to cut a wing and stabili-
zer plug. By that time, we had received our
Kuka robot and these were precision CNC
machined in the same MDF material as the
fuselage.
Once I had a set of plugs finely sanded and
primed, I started working on the paneling and
rivetting. Upon careful study of the real plane
pictures, it appeared that these Navy airfra-
mes had sustained some severe abuse
during Vietnam war and most of them had
marked wrinkles and wavy skin between the
stringers. I thought that it would be really cool
to reproduce these waves that I first saw on
the very impressive Skygate Collection Hawk
many years ago.
So I started tracing all the panel and stringer
lines and sanded the plug along these in a
wavy manner to create the skin ondulations.
However I carefully made these so that they
would only be noticeable in tangential light or
when touching the surface of the fuselage.
These came up extremely well, and after many
hours of fine tuning and sanding, I started pro-
ceeding with the panelling and rivetting.
Panelling was made from the pictures of the
real one and the Vought panelling manual,
with a mix of different thickness adhesive alu-
minum like Flight Metal. Rivets were punched
into the panels using a mix of tubes and rods
of different diameters relevant to the airplane
scale.
As explained earlier, the stabilizer design
required a very precise operating mechanism.
So I elected to make a very stiff setup. The
pivot point was computed to be at 17% of sta-
bilizer MAC for a good natural control stability,
moderate oscillation damping and reasonable
servo load. The pivot shaft itself is made from
aero certified alloy 2044 from Alcoa. We pur-
chase all our Alcoa aluminum directly at the
Lafayette factory in the USA with certificates
of origin. Al 2044 is specified by Alcoa as an
aero alloy specifically resistant to shocks and
fatigue cracking. Very useful on parts that are
subject to transport shocks and vibration. The
10 mm shaft is glued and double pinned in the
carbon fibre structure. I designed it so that it
would be as long as possible to butt againstAUTHOR: OLIVIER NICOLAS
XFLR5 screen shot of the wing, stabilizer and fin stream as well as fuselage interaction at low Reynolds numbers.A close-up of the optimized stabilizer and its interaction with the
wing at an AOA of 12 degrees and flap deflection of 20 degrees.A rear view of the wing and stabilizer vortices at 8 degrees AOA, as well as lift distribution curve. The stabili-
zer tips end up in the dog tooth mini vortices, which worried me and pushed me to optimize this partA close-up of the slats lip that seals the
control in clean and takeoff configura-
tions (up to 15 degrees of slat deflection)Crusader_Layout 1 07/03/18 17.13 Pagina 4