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U.S. ARMY APACHE

Desert Operations Present Challenges

By Bob Gradle, Experimental Flight Test Pilot

Flight testing new equipment is always an adventure.

Testing is essential to ensure the equipment operates functionally, as well as to demonstrate that it can perform properly and reliably in every environment anticipated over its planned life. Individual components, subjected to severe environmental conditions in a laboratory, must function in extremes including bitter cold, high heat, high humidity, punishing vibration, and electromagnetic interference. Once the components have demonstrated their robustness in a controlled laboratory environment, they must prove they can operate in the real world. To accomplish this, equipment testing advances to the field where engineering meets environment in a head-on collision.

In the case of military hardware, like an attack helicopter, it is usually impossible to conduct final system testing at the contractor's facility. Few manufacturers have the luxury of owning live-fire ranges that allow weapons testing to be conducted in a controlled and safe manner, so most live-fire testing is conducted at designated military test ranges, such as the U.S. Army's Yuma Proving Ground located near Yuma in southwest Arizona.

The Boeing Company, prime contractor for the U.S. Army's AH-64D Apache, is conducting engineering design and testing of the next version of the attack helicopter. The planned Apache Block III enhancements will replace several existing systems with upgraded components, designed to provide the Army aviator with increased war-fighting capabilities. New engines and transmissions, as well as new composite main rotor blades, will improve the high altitude/high-temperature performance of the aircraft. New mission processors, replacing the present suite of system and weapons processors, will provide significantly increased digital capability to the aircraft, which in turn will operate the upgraded targeting and pilotage sensors.

These upgraded sensors include an improved fire control radar (FCR) processor for target detection, as well as a tactical control data link (TCDL) that will give the attack helicopter community the capability to monitor and control unmanned aerial systems. An electromagnetic helmet tracker is replacing today's infrared tracker for improved reliability. Upgraded navigations systems add a much-needed instrument meteorological conditions (IMC) capability to the Apache, and the incorporation of other improvements will enhance the Apache's already formidable combat presence. Much of this testing is presently taking place in the summer heat in Yuma.

Four helicopters are engaged in systems evaluation in the desert, consisting of three U.S. Army AH-64D Apaches and an MD 530F helicopter, all out of the Boeing facility in Mesa, Ariz. Two of the Apaches are modified with the first round of upgraded Block III equipment; the third is a field-representative Apache Longbow that has been fitted with the improved radar electronics unit.

The fourth aircraft, a militarized version of the MD 530F helicopter owned by Boeing, unofficially dubbed the "Unmanned Little Bird (ULB)," has been modified with two new systems that allow that helicopter to fly as either a manned or unmanned aerial system (UAS). The ULB has a prototype flight-control-system capable of controlling the air vehicle through an entire surveillance flight without the need for human interaction. It can also be fitted with any current operational sensor package. This assemblage of rotary-wing aircraft, following initial systems evaluation at the company facility, deployed to the Yuma Proving Grounds to demonstrate operational capability in the scorching heat of the desert Southwest.

One of the Apaches, under the control of Test Director Sonny Ellis, is a standard AH 64D Apache helicopter that has been fitted with the upgraded Radar Electronics Unit. A Combined Test Team, including both contractor and government pilots, flight test engineers and instrumentation personnel, has been flying test missions against an array of both stationary and moving vehicular targets for the past two months. The first of the two Block III prototype Apaches, operating under Leo Hatfield (test director), has been participating in the evaluation of the upgraded radar system and the new helmet tracker. Bob Whittington (test director) leads testing of the second Block III aircraft, equipped with a TCDL that replaces the FCR and allows the Apache to establish contact with and control an airborne sensor. The ULB employed at Yuma serves as the aerial sensor for the purposes of this evaluation.

The ability to team the Apache with a UAS greatly enhances the aircraft's mission capability in four ways. First, access to the UAS will allow the aviator to see more of the battlefield than he can today. The UAS operates at a higher altitude than the Apache and is usually placed in an orbit some distance from the helicopter. The aviator can thus see not only the engagement area around his own position, but also a second section of the battlefield around the UAS.

Second, the aviator can view potential threats and targets from a different battlefield perspective. The Apache has a Modernized Target Acquisition Designation Sight (M-TADS) located in a turret mounted on the nose of the helicopter. This turret contains separate day television and infrared sensors with selectable magnification levels, plus a targeting and ranging laser. Using the TADS, the Apache can survey the battlefield, select a target and illuminate it with the laser for engagement. The inherent limitation of this process is that the current Apache can only see the battlefield from its own point of view. As an example, the gunner can see the building that's four kilometers in front of him, but he can't see the enemy tank that's hidden behind the building. By directing the UAS into an orbit on the far side of the building, transmitting target location to the UAS to automatically direct the UAS sensors to the area of interest, and then accessing the video feed from the UAS sensor, the aviator can now see that hidden threat in real time.

Third, many of the unmanned aerial systems have onboard laser designators that are compatible with the helicopter's anti-armor missiles. The Apache helicopter uses this capability to attack targets while remaining behind cover. It does this by deploying its Hellfire missiles while using the UAS laser to designate the target, all the while remaining hidden from enemy detection. Sensor and target location data is automatically transmitted between the UAS and Apache to enable both platforms to automatically cue sensors and weapons to the same area of interest and eliminate ambiguities.

Finally, the Apache will be able to take the video feed from the UAS and send it on to other attack elements for engagement. The information may go to another deployed Apache unit or back to the command structure for assignment to ground attack unit.

In addition to the obvious challenges for the equipment, including blowing dust and unrelenting heat, desert operations often present unique challenges for the folks conducting tests. The desert Southwest, far from being the vast, lifeless sand dune depicted in B-movie westerns, is home to a vast array of plant and animal life, most of which have developed sophisticated and effective defense mechanisms that enable them to survive in the harsh climate. A recent encounter in the desert provided a reminder of this, when the early morning maintenance crew opened the aircraft hangar to discover a three-foot rattlesnake curled up on the floor outside the men's room door. Such encounters with nature serve as a constant reminder that people and aircraft must frequently overcome significant challenges to operate in foreign, hostile, and enchantingly beautiful locales.

 

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