Scaled Composite's Cory Bird Creates What Could Be The Most
Accurately Built Aircraft Ever
By ANN Contributor Christopher Armstrong
At this year's Airventure in Oshkosh (WI), parked right next to
the old entryway arch, is a yellow, two-seat airplane that is so
perfectly built it grabs your eye from a hundred feet away.
You stop dead in your tracks. You forget what you were doing and
walk straight up to the plane.
Up close, it's even more impressive. Built to the closest
machinist tolerances, the plane was, at one time, perfect to
1/1000th of an inch when it was unveiled. You would still be hard
pressed to find any flaws now, but its creator says there have
indeed been few dings and chips since he started flying it last
year. Cory Bird, a project engineer who worked on Scaled
Composites' White Knight carrier plane, also says he has overheated
the brakes, which softened the epoxy of the carbon fiber wheel
pants. Still, "Symmetry" is near-perfect.
The access panels, inspection plates, fasteners and
imperfections that trip the airflow over most aircraft are nowhere
to be seen on Symmetry. The joints in the cowling, flying surface
to fuselage joints and control surfaces are so tight they can
barely be seen. Only a few screws are to be found on the exterior
of the aircraft. The large pitot tube found on most planes is
replaced by a tiny opening on the nose of the left wheel pant.
The tail wheel retracts into the fuselage and the opening is
perfectly sealed by the gear door. Even the fuel tank drains are
flush with the belly of the plane, not protruding below the surface
as most fuel drains do. Bird took the time to machine the fuel
drains so they would fit perfectly.
The cowling is another example of the lengths to which Bird went
to keep his aircraft aerodynamically clean. Most airplane cowlings
are held on by dozens of fasteners. Symmetry's cowl is attached to
the firewall by a circumferential groove and three locking pins.
The pins are released by a handle hidden under the oil check door
and locked closed using a rivet as a safety pin.
The oil check door is cable-released by a remote flush fitting
button located inside the right side cooling air inlet and holds
the safety rivet in position when closed. The sides of the cowl are
held together using hinge pins inserted through the air inlets.
Access to these is achieved by removing the inlet to engine
baffling skirts, which are removed by the only two screws on the
front of the plane, which are hidden deep inside the inlets.
With top cowling removed the engine compartment is revealed and
it is as carefully finished as the exterior of the plane. The
firewall is polished to a mirror surface which reflects engine
components and the carbon composite baffles that Bird says where
among the more difficult parts to complete to his standards. Even
the insides of the cowling look better then the outsides of most
airplanes.
The fuselage was built by pulling a mold off a plug the shape of
the fuselage. The fuselage halves were then made by hand-laying
fiberglass into the molds. The wing is one piece tip to tip. Both
the wing and the horizontal stabilizer are constructed using the
moldless composite techniques developed by Burt Rutan for his
VariEze in 1976. To remove the wing, the wing to fuselage fairings
and instrument panel are removed. Then the wing attach bolts are
removed and the wing slides straight out the side. Most of the
plane is constructed using fiberglass, with carbon fiber only used
in the high stress areas.
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Continued in Part Two: Symmetry's Interior and Performance