Boeing 7E7 First to Use Electricity to Power Cabin Systems
The proposed Boeing 7E7 will be the first airliner to use electricity
instead of bleed air from its engines to power its environmental
control and cabin comfort systems -- if Honeywell Aerospace's
proposal is chosen in Seattle.
The chance to apply new technology on this scale comes only once
every new airliner, and Honeywell is pulling together technologies
from across its aerospace and industrial controls businesses to
offer systems that are significant step beyond those of today.
It is also proposing to develop a distributed power system integrated
with and controlled by its Primus Epic avionics to supply electricity
on demand where and when needed by motors and cabin equipment
throughout the aircraft.
"Just eliminating bleed air from the engines will improve
fuel efficiency by 2% and eliminate the need for all the ducting,"
said Roger Wolfe, VP for airframe systems technologies.
Honeywell says all the compressed air requirements in the aircraft,
from pressurization to air quality, can be met electrically. But
providing enough power will need generators on each engine of
up to 200 kW, roughly twice the size of the biggest now flying,
on the Boeing 777.
Wolfe believes the generators can also be used as engine starters,
and will be designed to handle the tremendous torque involved
in spinning up a large jet engine.
Gretchen McClaine, VP of technology at Honeywell, said the company's
philosophy of two functions on one shaft (starter and generator)
is also used on the Joint Strike Fighter and in some APUs. It
could find its way into an APU for the Boeing 7E7 if Honeywell
provides complete systems, as could oil-less air bearings.
The technologies offered for the Boeing 7E7 could also form part
of Honeywell's bid on the European A400M transport, both executives
said.
Meanwhile Honeywell continues to invest heavily in research to
make its engines and APUs cleaner and quieter. They include new
technologies in combustion to reduce emissions, in sound-absorbing
materials, engine design to reduce harmonics and noise signature
(such as interaction between blades and vanes), and forward-swept
fans. Honeywell is also driving filtration technology to make
cabin air systems lighter and cheaper, as well as to enable more
widespread use on smaller airliners, McClaine said.
