Helmet mounted sight ODEN

Sighting information presented on the visor

With a fighter aircraft equipped with the HELMET MOUNTED SIGHT, HMS system ODEN, the pilot can aim at the enemy with the HMS instead of using a standard sensor with limited ability to move. At flight tests time-savings with more than several seconds have been proved for locking up the seeker. The possibility to lock on several aircraft within a short time range has also increased considerably, compared to earlier when the sensor had to be guided.

The pilot can slave the aircraft's radar, the missile seeker and other sensors with the HMS system. The HMS system provides the pilot with visor presented information before attack. It is possible to use the same system for aiming of sensors also in army and navy applications.

HMS system ODEN
Performance increasing equipment

Through using a HMS system a pilot can guide his sensors outside the normal search programme. A faster locking up is achieved through guiding the sensor towards the right area straight away and the normal search programme will then find the target.

A HMS system will have its complete function when it is working together with an short range air-to-air missile which has a high manoeuvring ability. The pilot can then fire his weapons in a position that earlier was impossible, this to avoid being shot down.

Working area for helmet mounted sight system:
[Sketch showing greater aquision volume]

FFV Aerotech's HMS system ODEN is a further development of the original flight helmet 116 which is a standard helmet for the Swedish Air Force. The only change is an optics which has been integrated to the helmet shell with a protective hood on the outside. The HMS system using the same oxygen mask and manoeuvring of the visor as the original helmet system.

The HMS system ODEN fulfils the same requirements for flight safety as the original system and has been blast-tested in a wind tunnel with approved result.

Symbology

HMS system ODEN uses static presentation of symbols for aiming of targets. The presentation consists of a hair cross, four arrows and presentation of the current choice of weapons.

Shown is the symbol configuration for prototype of HMS ODEN.

Systems description

The HMS system consists of the following subsystems

Helmet with relay optics and display. This fulfils the same requirements as the original helmet system.
Helmet tracker system. This consists of an electronic unit, a transmitter and a sensor. The system is built on the magnetic principle with a generated magnetic field for positioning the helmet's position. The electronic unit also runs the display on the helmet which consists of ordinary LEDs.

The electronic unit communicates with the aircraft's mission computer via either a bus- or a series communication. There is a possibility for other subsystems in the aircraft to communicate with the HMS system.

FFV Aerotech's HMS system is a high performance low cost alternative with sufficient performance to heavily increase the combat ability of the aircraft.

Technical data

Working range:
yaw ą 180 degrees
pitch ą 90 degrees
bank ą 180 degrees
Head-motion-box:
X(Front-Rear) ą 406 mm
Y(Left-Right) ą 254 mm
Z(Up-Down) ą 152 mm
Update rate, tracker: 60 Hz
Time delay, tracker: 46 ms
Resolution:
angular 1.75 mrad, 0.1 degree
translation 2.54 mm
Accuracy:
"HUD" box 2 mrad (RMS)
Others 4-10 mrad
Power supply:
115 V ac, 0.7 A, 400 Hz
28 V dc, 0.1 A
Transmission visor: 83% (blue-green light)
Reflection visor: 83% (red light)
Total weight: 1.35 kg
Field of view: 6 degrees
Exit pupil: 18 mm
Range: Depending on sight conditions and the range of the radar
Possible colloborating systems: radar, missiles, OTIS, FLIR, camera
Accuracy system: Better than 1 degree

The new Swedish air combat suit, including helmet

Military aviation
Text last modified 1996 Sep 27, content reviewed 2000 Sep 15 by Urban Fredriksson
Text via Nicklas Friberg, FFV Aerotech AB