2013 APRIL / Vol. 5 / No. 4 /
GA
41
fuselage parasite and trim drag and
aerodynamic download that requires
an increase in rotor thrust; these
effects increase power required.
The Drive System survivability
is integrated with the aircraft design
to allow continued aircraft operation
with one fan operating or with both
fans inoperative with the main
gearbox functioning normally. The
fans may be damaged or the center
and/or either fan gearbox may be
damaged or have the lubrication lost
and the main gearbox can power
the aircraft back to a safe landing
site using the main rotor controls
and power to the main gearbox.
The main transmission is
designed to continue to rotate
without lubrication but the gearbox
may lose power. The gearbox
is designed so it will not jam if
lubrication and power is lost so
the aircraft can operate similar to a
gyrocopter with the fans providing
the propulsion and the main rotors
providing the lift. This allows the
aircraft to find a suitable landing
site and auto rotate to the ground.
The AVX fans can be used
to decelerate while approaching
a landing with a 5-10° nose
down approach, eliminating the
need to flare to a hover, which
could dramatically decrease
the risk of "brownout".
Additional studies are
being performed. ·