eVader 6D
email:  garyg@gressaero.com

Please note:  Address info@gressaero.com
no longer exists.  If you did not receive a reply
please send again to the above address.  I
appologize for any inconvenience.
eVader 750
Educational video: Propellers as CMGs
and momentum wheels
for 3D attitude
control in air
and outer space
Nymbus and eVader 6D on display at Ottawa's Aviation and Space Museum, 2012
Oblique Active Tilting Overview,  AHS (2007) - Gress
Gyroscopically Controlled Air Vehicle (2012) - Thorne
Multirotor UAV with Tilting Rotors (2013) - Segui-Gasco
UAV having Two Tilting Rotors (2005)- Kendoul et al
Discovery Channel (Daily Planet) segment on Gary's aircraft and their control (2007)
Nymbus 650/ nVader 7
Only two rigid, non-cyclic propellers are
required to hover an aircraft if they are
controlled by Oblique Active Tilting (OAT).  In
this way the propellers become
(control moment gyroscopes) and
momentum wheels, both of which are used
to control orbital satellites and space

The inertial control moments produced do
not depend on distances to the aircraft center
of mass and, of course, are independent of
the atmosphere and wind gusts.  The aircraft
you see here are fully controllable about all
three axes in outer space! (see video on right)
Related theses and papers:
Enhanced Aircraft Hover Control
using Propeller Dynamics
Gary's artwork at Fine Art America
Nymbus composite, 2011 (5 min)
Gary's artwork on Facebook
Gary Gress
University of Calgary
Passively Stabilized VTOL Aircraft (2014) - Gress  MSc
Nymbus at U of C  2013 (1 min)
Nymbus over lake, 2011 (2 min)
PS bicopter undergoing testing.  Aluminum rings attached to commercial propellers increase
their moment of inertia and allow
aircraft self-stabilization in pitch and roll.
The team of engineering students at U of C responsible for the design, analysis,
construction and testing of the inertial rings.  From left to right: Austin Mireault, Derek
Chen, Brendyn Stone,  David Dyck, Jovana Cuzovic, Jeff Woolsey.  (April 2015)
Rigid-Propeller Bicopter VTOLs
OAT** Bicopters sold:
PS* Bicopter Research:
Pitch Control of OAT Bi-rotor (2014) - Blouin-Lanteigne
(**Oblique Active Tilting)    
(*Passively Stabilized)    
Inventor of Oblique Active Tilting (OAT)
Bicopter Passive Stabilization.