Apache Longbow Helicopter Upgrade Launches the Future of Airborne UAV Management

06/28/2011  Neil Waghorn - defenceiq.com

The Block III upgrade for the Apache Longbow AH-64D promises to drastically improve one of the best attack helicopter platforms in the world. The upgrade is to include composite main rotor blades, an improved drive system and upgraded 701D engines (which will restore A-Model performance lost due to the weight of the D-Model). The upgrade is also meant to include the Joint Tactical Radio System (JTRS), designed to link Land-Sea-Air platforms and allow immediate communication. Despite recent successful demonstrations of this technology, owing to an extremely troubled and delayed development history, some industry experts are sceptical that the JTRS will be included in the initial Block III upgrades.

One remarkable technological modernisation will be the upgrading of Apache control over UAVs – a feature that will radically transform Apache situational awareness and enhance the capabilities of an already versatile system.

This increased control of UAVs, or UAS (Unmanned Aerial Systems), comes through the introduction of advanced Levels of Interoperability (LOI). There are several different Levels of LOI. At the bottom rung is Level 1: the Apache is able to receive data and streaming video from the UAV indirectly (via relay from base). At Level 2, this information comes directly from the UAV. At level 3, the Apache can receive data and gains control over the payload (sensor or missile), allowing a certain level of interaction. The level 4 upgrade brings almost true interoperability, with the Apache being able to view the data feed from the UAV, control its payload and exert a level of control over the flight path of the UAV in certain situations. The envisioned final rung of the ladder would be Level 5, at which point the Apache will possess complete control of the UAV, including takeoff and landing phases of flight.

Heightened situational awareness in the combat environment

The key feature of LOI 4 is that it improves Apache situational awareness over the existing LOI – a standard that operators have already deemed excellent. The existing capabilities allow Apaches responding to a call for from troops on the ground (FAC or JTAC) to view footage from a loitering UAV asset whilst en-route to the area – allowing them to arrive knowing where the friendly troops are located relative to FEBA (Forward Edge of the Battle Area), as well as potential threats. This situational awareness is improved when at a target area, as LOI 3 allows the Apache sensor to be synched to the exact location that a UAV is surveilling. This allows the Apache crew to view the target from above (courtesy of the UAV), and from a low altitude aspect view from the Apache – allowing the construction of a more complex perspective of the target area. Boeing Experimental Flight Test Pilot, Bob Gradle, comments on this particular improvement, highlighting that this dynamic aerial view would enable the Apache to visually acquire a tank that might have previously been obscured by a building. 

The addition of LOI 4 to these capabilities now allows the crew to build two separate site pictures from two divergent perspectives. Real time image updates from a loitering UAV can be presented side-by-side with Apache M-TADS (Modernized Target Acquisition Designation Sight) imagery. Additionally, this information can be provided to the crew without the time delay (and task saturation) induced by directing a remotely based UAV pilot. This shortening of the sensor-to-kill loop has been referred to by the Apache Block III Product Office and Aviation Flight Test Directorate as ‘taking the TV remote control instead of talking your spouse through channel surfing.’  The ability for Apache crews to gain control during critical targeting phases will allow faster reactions in the midst of what is already a complex and dynamic process.

Sharpening the ISR edge

The ISR impact of Level 4 integration will be large, with the potential of Apaches being possible to direct a UAV to examine a target that had not be originally observed, or had emerged after a UAV pass. The ability to insert waypoints into the flight path of a UAV will enhance the already existing capability of LOI 3 to control UAV sensor suites. As UAVs move towards increased autonomy, Apache operators’ ability to direct a UAV within a target area will provide an airborne ‘human in the loop’ – an effective alternative to conventional ground-based operators.

Problems of LOI 4

The Apache Block III Product Office describes certain concerns regarding LOI 4 as ‘myths’. These include:

    The Apache Pilot’s workload is increased to a detrimental effect by the addition of LOI 4

    LOI 4 involves flying a UAV by ‘stick’ from the Apache

    Team flying between a UAV and Apache will result in ‘formation flying’

They assert that, because of the crew’s limited time in control of the UAV, coupled with the integration of UAV controls within existing cockpit controls, there is far less of a detrimental effect than some worry about. The integration of the UAV control within the existing cockpit controls also seemingly disproves the ‘stick’ myth. The control of the UAV is not that advanced.

LOI 4 only offers the Apache pilot or co-pilot the following control options:

    HOLD Mode – circles around current location

    DEST (Destination) Mode – fly to a location and circle

    PROG (Program) Mode – fly a designated route

    GUIDE Mode – circle around sensor target (the Apache can target this and the UAV will adjust accordingly)

To the flying formation claim, the Product Office highlights that the UAV will be ‘typically miles away from the Apache and at a much higher altitude’, and that the pilot will only have limited control of the UAV for short periods of time rather than the entire flight.

The Block III Program, scheduled for initial low rate delivery in late 2011, will provide yet another update to the Apache and hopefully ensure that it remains a valuable tool in the US Army arsenal for many years to come.  The cost to the DoD will be just short of $700m which, in conjunction with the demise of the RAH-66 Comanche project, will place increased pressure on this and similar legacy upgrades to extract added value from the middle aged Apache airframe. By focusing on improving situational awareness and reducing task saturation in the cockpit, the LOI 4 upgrade also aims to further reduce collateral damage and blue-on-blue incidents in the battlefield, further adding political value to its attack capability. It is with these requirements in mind that the US Army has once again chosen the AH-64 Apache Longbow as the service’s primary attack helicopter for at least another decade.