and supplied the cockpit briefing,
showing us the glass instruments that
take the place of the basic six-pack.
Eureka is currently certificated for
visual flight rules (VFR) flight, though
instrument flight rules certification
is pending. Her presentation
included the all-important gauges
that show temperatures of the air
and the helium in the ship’s three
gas envelopes, known as ballonets.
One holds helium; the other two
are filled with air. The outside air
temperature compared to the helium
temperature is key to determining
how much lift the airship has. As
the lifting gas cools, with altitude,
for example, it will contract and
decrease in volume. When the lifting
gas warms, it expands and increases
in volume. Using onboard heaters
to heat the helium produces an
effect known as “superheat,” which
increases the airship’s available lift
by approximately 100 kilograms
for each 3°C increase of helium
temperature above the outside air
temperature.
The pilot controls the ship’s lift
by monitoring the amount of air
