Digital eyes

The cancellation of the contract for the 126 French Rafale medium multirole combat aircraft  has drawn attention to the future of a very significantly important battlefield tool-head mounted display-that helps ensure a “first shot kill” from within a fighting platform.

A burgeoning joint venture between an Indian private sector company Samtel Avionics and the French company Thales that specializes in high-end airborne electronic systems for supply of helmet mounted displays appears to have been nipped in the bud with the cancellation of the Rafale contract and reduction of acquisitions to only 36 aircraft in flyaway condition.

A head mounted display when applied to a fighter aircraft, gives the pilot a panoramic view outside the cockpit and enables him to engage targets “off boresight” with missiles that automatically head in the direction in which the head is pointed. It eliminates what for long has been the standard operating procedure of maneuvering one’s aircraft to “get on the tail” of the target before releasing the missiles or firing the guns. It has added a new dimension to dogfights in the air enabling engagement of target as much as 80 degrees on either side of the centerline of the cockpit.    

Situational awareness

Air-to-air warfare has long depended on the acuteness of the peripheral vision of the pilot. What he could see “from the sides of his eyes” without looking in the direction of the intended target added to his situational awareness. It is this quality that has been enhanced with the use of digital technology and miniaturized sensors that read the direction in which the eyes are looking to  “cue” the missile in that direction.

Chances of a target aircraft managing to evade being hit are substantially reduced given that modern missiles too travel at high subsonic speed and India’s Brahmos has broken even that barrier with its supersonic speed and its beyond-visual- range capability in ground attack mode. India is also preparing to induct the Astra air-to-air missile to its fighter fleet.   

Head mounted display systems need to be light enough not to create difficulties for the pilot when operating in high “g” (gravity) conditions when blood circulation in the head is affected by the force of gravity drawing down the blood  towards the legs during these high “g” maneuvers. This phenomenon can cause “greyouts” in which the pilot has difficulty in focusing his eyes on cockpit instrumentation. With the external ambient information focused on a head-up configuration, the pilot has greater control of the situation than earlier. Because there is little need for supersonic  flight,  helicopters tend to be ideal platforms for operations with head mounted displays.   

There is rapid improvement in head mounted display systems since the South African Air Force first introduced it to combat the Soviet supplied MiG aircraft to countries on its periphery. The Soviets responded with their own display system slaved to the R-73 short range air-to-air missile for dogfights and managed to regain air superiority. By this time the Israelis had also managed to gain expertise in head mounted displays which it married with its Python-4 air-to-air missile to gain a regional advantage and air superiority over its Arab neighbors most of whom were clients of American equipment. The Americans, however, were lagging behind in this technology and were still dependent on the legacy head up display system within a glass cockpit configuration. The Soviet technology slipped into western hands with the reunification of East and West Germany. The former was using the MiG aircraft fitted with head mounted displays.    

Experimental work on new technologies is underway in many laboratories. One of these is on sensors that would accurately measure the direction of the eye in relation to the position of the head. In an attempt to improve peripheral vision the pilot tends to slew his eye sideways even as the head is held straight. Or, conversely, in the midst of maneuvers during aerial combat many a time the head and eye are not in sync. The new device would take the cue to the missile from the eye and not the more generalized direction of the angle of the head. Another new gadget on the drawing board is a direct laser-enabled display within the pilot’s retina that would enable him to get a larger field of view than what he would get in the head mounted display system.  

Increasing demands

More of the arms producing nations are working on their own head mounted display systems in conjunction with indigenous missiles. This combination increases the unit value of the missile system as manufacturers market them as a composite whole. The offer of “one shot sure kill” has a tremendous impact on the overall deployment of the air fleet, making for greater efficiency per sortie and hence reduction in the cost of operations. In short, a smaller fleet of even legacy aircraft like the MiG-21 series can be very gainfully employed with the new systems.

In the particular case of the Rafale jets, the Indian company Samtel Avionics had formed a Joint Venture with the French Thales which provides the cockpit avionics suite inclusive of the head mounted displays. The Thales components have also been incorporated in the navalised version of the MiG-29 air superiority and surface attack fighter and the massive retrofitting and upgradation is currently underway in the French supplied Mirage 2000 aircraft of the Indian Air Force. Given the large numbers of MiG-29s and Mirages in the Indian Armed Forces and many nations in South East Asia and West Asia also using these ex-Soviet aircraft  the Joint Venture can still succeed in its quest of creating a hub in India for head mounted display systems for upgradation, repair and maintenance.

Apart from helmets for pilots there appears to be a huge market for combat headwear for tank, infantry combat vehicles and mechanized infantry crew. One estimate suggested that as many as 5000 head mounted display systems would be required by the Army alone.  Here too, in a separate joint venture with General Dynamics of Canada Samtel Avionics is bidding for the supply of head mounted displays for the whole range of fighting vehicles including the T-72 tanks that are the backbone of the armored regiment. For long there have been complaints that Indian Army tanks are “night blind” because of inadequate night vision devices. The new headgear is intended to cater to both the day and night fighting capabilities of tanks and ICVs.

There have been demands for panoramic viewfinders for Indian tanks. These allow the tank commander to scan the countryside even while the turret canopy is shut. This raises a question about the feasibility of garbing the commander with a head mounted display while he is locked within the tank. The best configuration is that the commander in his head mounted display operates with the canopy open. This factor, as the lessons of the Sri Lanka deployment of the Indian Peace Keeping Force had shown, tends to make the commander vulnerable to small arms fire. In the urban guerrilla warfare in Jaffna tank commanders travelling with canopies open suffered head injuries in built up areas.