Piloting a rotorcraft in a Degraded Visual Environment (DVE) is a very complex task, and the evolution of the rotorcraft
missions tend to augment the probability of such degraded flight conditions (increase of night flights, all-weather flights,
with brownout or whiteout phenomena…). When the direct view of the external situation is degraded, the avionic system
can be of great help for the crew to recover the lost visual references. TopOwl® Head Mounted Sight and Display
(HMSD) system is particularly adapted to such situations, allowing the pilot to remain "eyes-out" while visualizing on a
large field of view different information: a conformal enhanced image (EVS) coming from an on-board sensor, various
2D and 3D symbologies (flight, navigation, mission specific symbols), a conformal synthetic representation of the terrain
(SVS), a night vision image coming from the integrated Image Intensifier Tubes, or a combination of these data,
depending on the external conditions and the phase of flight, according to the pilot’s choice.
TopOwl® is an original concept of binocular Helmet Mounted Sight and Display system (HMSD) for helicopters, where
two Image Intensifier Tubes (IIT) are integrated on the headgear and optically coupled to the clear visor placed in front
of the pilot's eyes.
Thales recently developed a new version of its TopOwl®'s Display Module with the objective to have an HMSD capable
to achieve all kind of missions up to the darkest night levels. The main enhancements are the redesign of the optical
combination, the use of new optical materials and of latest generation of optical design tools.
Two flyable prototypes of this new design were manufactured. A performance assessment has been conducted, showing
a significant improvement of the night vision performances, reaching performances equivalent to those of last issued
NVGs. These evaluations are being completed by different flight test evaluations.