Tactical Airborne Displays Advance to High-Performance Commercial Technology

March 1999
By Edward J. Walsh

Pilots eye targets, then engage controls without looking down or maneuvering into firing position.

Maintaining air supremacy soon may be easier for U.S. fighter pilots equipped with the latest helmet technology. Head-tracking display screens are being designed to allow target designation with little more than a pilot’s nod. The introduction at the end of the 1980s of the Soviet AA-11 Archer air-to-air missile revealed a serious deficiency in U.S. capabilities. That deficiency took on increasingly ominous significance as Russian-built aircraft and air-launched weapons, integrated with helmet-mounted sights and capable of being launched at up to 90 degrees off boresight of a target, proliferated widely to governments hostile to the United States. The problem is now being addressed in a joint U.S. Navy-U.S. Air Force effort, which combines the AIM-9X missile, an advanced short-range dogfight weapon with a targeting device that can aim sensors and weapons wherever a pilot looks.

Despite funding constraints, the Navy and Air Force pushed ahead with situation awareness improvement initiatives aimed both at new aircraft and current aircraft inventories. In October and November of 1998, their efforts paid off when Air Force and Navy pilots successfully flight-tested a joint helmet-mounted cueing system aboard an Air Force F-15 Eagle and a Navy F/A-18 Hornet aircraft. The joint helmet-mounted cueing system (JHMCS), as an element of a new high-off-boresight seeker AIM-9X air-to-air missile, would give U.S. pilots the long-needed ability to launch well off boresight.

The system features a magnetic head tracker integrated with a display that is projected onto the pilot’s visor. The system gives aviators the ability to aim sensors and weapons by simply turning their heads and engaging the controls, and it permits them to view all cockpit display data without looking down. Because of the seeker capability of the AIM-9X missile, the system permits the pilot to engage targets without wasting critical seconds maneuvering the aircraft into a firing position. The technology will be deployed for Air Force F-15s, F-16s and F-22s, and Navy F/A-18s.

The Boeing Company, St. Louis, and Lockheed Martin Tactical Aircraft Systems, Fort Worth, Texas, are both prime contractors for the JHMCS joint-service program office. Vision Systems International, a combined venture of Elbit Systems Limited, Haifa, Israel, and Kaiser Electronics of San Jose, California, is the prime subcontractor on this project. Elbit has built a similar system for the Israeli Air Force, and European companies are developing new display and cockpit systems for the tri-nation Eurofighter single-seat fighter aircraft.

The U.S. Navy and the U.S. Air Force, through a number of separate and joint research programs, have sought to enhance the level of situational awareness of tactical aircraft pilots. Such efforts aimed to capitalize on breakthroughs in processing and display technology to give the pilot a clearer view of the fast-changing air picture in a highly complex air-combat environment.

A number of companies, including Boeing, Kaiser Electronics and Flight Visions, developed prototype systems, capitalizing on such technologies as active matrix liquid crystal displays (AMLCDs), both under contract to the services and as independent research and development programs. Both the Air Force’s F-22 Raptor advanced tactical fighter and the Navy’s F/A-18E/F, the next generation of the F/A-18C/D Hornet attack aircraft, will be equipped with AMLCD displays.

Early work, such as a project by Boeing (then McDonnell Douglas) in the 1990s to develop a conceptual 100-square-inch cockpit display, was aimed at supporting pilots for extremely fast-moving, air-to-air dogfights with high-performance Soviet fighters. Although the Cold War is over and the likelihood of old-fashioned air-to-air combat has diminished, the mission load for U.S. tactical aircraft pilots and crews has increased dramatically as Air Force and Navy tactical aircraft have now been configured for both air-to-air and precision-strike operations. The air-to-air threat, moreover, has not disappeared, experts agree.

Now, in addition to the Navy-Air Force JHMCS program, the joint strike fighter program may also adopt the new targeting system. Lockheed Martin and Boeing are leading the two joint strike fighter industry teams. GEC Marconi of the United Kingdom is providing a head-up display, or HUD, system for Boeing’s joint strike fighter concept-demonstration aircraft.

GEC Marconi is building HUDs for the Eurofighter as well. U.K.-based Pilkington Optronics is providing the helmet-mounted sight for the program, and Smiths Industries, also based in the United Kingdom, is producing a head-down display. A display processor, another GEC product, will integrate the head-up and head-down displays and the helmet-mounted sight.

The U.S. Navy is managing a number of independent research and development initiatives, some of which include new display capabilities to reduce pilot workload while increasing warfighting effectiveness. In late 1997, the Navy introduced, for its new T-45 Goshawk primary jet trainer, the Cockpit 21 configuration that familiarizes student pilots with the digital cockpits of newer tactical aircraft. Cockpit 21, developed by Boeing as the prime contractor and systems integrator for the T-45, introduced cockpit digital displays to replace the analog displays of the original T-45 design.

More advanced work is underway at the Naval Air Warfare Center Aircraft Division, Patuxent River, Maryland, where the crew systems department is working in collaboration with Boeing on a program referred to as “effective information fusion for helmet-mounted display technologies.” The initiative, involving the F-22 joint strike fighter and a future Navy common support aircraft, is aimed at developing optics and processing technology needed to display, inside the pilot’s helmet, aircraft-systems information such as speed, altitude, weapons status and targeting data.

The Navy, meanwhile, is seeking to capitalize on new display and processing technologies to enhance situation awareness for its older F-14 Tomcat fighters. Various initiatives are underway to extend the life and mission range of the aircraft by applying new thinking about technology insertion, systems integration and systems engineering already being used for the F/A-18E/F program.

The F-14 Tomcat, first fielded in its “A” air-to-air fighter-only variant in 1973, is going through several weapon, sensor and processing enhancements, both to preserve its status as the world’s premier air-superiority fighter and to give it a precision-strike capability. The Navy’s Tomcat “roadmap for the future” encompasses installing a low-altitude navigation and targeting infrared/night system aboard the F-14 fleet to support the precision-strike role. Work is essentially complete for the 50 F-14D variants, which were remanufactured in the early 1990s primarily with an engine upgrade and the introduction of several digital systems.

The roadmap also calls for the introduction of digital flight controls, an improved defensive electronic countermeasures system, the ALR-67(v) radar warning receiver, a global positioning system receiver and a tactical airborne reconnaissance pod system that includes an integrated databank and digital imaging.

Flight Visions, Sugar Grove, Illinois, will be providing critical elements of an enhanced F-14 cockpit, initially for the “B” variants. The company provides head-up and head-down displays, mission processors, symbol generators and cockpit-system software both for U.S. and international tactical aircraft.

Northrop Grumman Corporation, Herndon, Virginia, prime contractor for the F-14, awarded Flight Visions a production contract valued at $9 million for a cockpit integrated instrumentation group of systems as part of the F-14B upgrade program. The instrumentation will consist of three elements: the Flight Visions Sparrow Hawk head-up display, the FV-3000 modular mission display processor and a head-down primary flight display. The complete architecture will replace the aging vertical display instrumentation group now in use aboard F-14Bs. The contract calls for production of 82 units, with deliveries to the Naval Air Station, Oceana, Virginia, to start in June and ramp-up within a few months to seven systems per month.

The F-14B instrumentation upgrade contract is Flight Vision’s first for an operational U.S. tactical aircraft program. In addition, as a subcontractor to Lockheed Martin Aeronautical Systems, the company is providing its new Night Hawk advanced-stroke raster HUD for Lockheed’s joint-strike fighter concept demonstration aircraft. Flight Visions has delivered Night Hawk test units to Lockheed and soon will deliver the first flight-test Night Hawk.

Robert Atac, president of Flight Visions, says that the three elements of his company’s systems are tightly linked, both to provide fully integrated cockpit display control and to offload some processing functions from the obsolete F-14B AWG-9 fire-control and radar processor, a 1960s-vintage system developed by Hughes.

The Sparrow Hawk provides a 25-degree instantaneous field of view. The system weighs slightly more than 17 pounds. Optional features include an up-front control panel that permits the pilot to select a system mode and a HUD color camera fitted with an electromechanical automatic light-sensing aperture that can automatically adjust light exposure. A video recording system can be integrated with the optical system. The system includes two symbol generators; the first serves as a primary and the second as a backup.

The Sparrow Hawk also includes an integral combiner. This flat piece of glass is situated between the pilot and the windshield and reflects the HUD image into the pilot’s field of vision. Atac explains that initially the combiner was built into the F-14B windshield, a configuration that, while it limited the number of components, required both the combiner and the windshield to be precisely aligned and the combiner to be perfectly flat. Any curvature would contribute to error. The Navy discovered that as the aircraft gained speed, the high-velocity airflow caused the windshield to flex, distorting the image reflected in the combiner.

The Navy tried to solve the problem by using a thicker windshield, which instead caused multiple reflections and “ghost” images. The Sparrow Hawk combiner, Atac says, permits the heavy F-14B windshield to be replaced with the thinner night-vision-compatible windshield used on the F-14D.

Flight Visions has supplied the Sparrow Hawk for the Czech L-159 and L-139 fighter aircraft, the Pilatus PC-9 and PC-7 Mark II trainers, the Israeli air force Kfir fighter, and several turboprop trainers used by the Polish, Romanian and Tunisian air forces.

The company’s Night Hawk, slated for the Lockheed Martin joint strike fighter concept demonstration aircraft, is a 30-degree-field-of-view system and offers a 6-inch aperture to provide an instantaneous wide and tall field of view to support a wider “aim envelope,” company officials say. Like the Sparrow Hawk, it provides, as options, the integrated color HUD camera and video recorder and an up-front control panel.

The FV-3000, integrated with head-up, helmet-mounted and multifunction displays, can be employed for tactical aircraft weapons delivery and navigation control.  The system processes signals provided by a range of aircraft subsystems and generates symbology for display on a HUD or helmet-mounted unit. The FV-3000, which weighs about 18 pounds, consists of dual 36-million-instructions-per-second processors linked to two dual-redundant databuses and a raster-on-stroke HUD driver. Company representatives say that the new instrumentation group for the F-14B is compatible with the aircraft mounting and wiring, and no modifications are needed to aircraft mission computer software.

Atac says that the incorporation of the Sparrow Hawk HUD and FV-3000 processor into the F-14B is aimed primarily at cutting logistics costs by shifting the program toward commercial-based hardware and software and away from the aircraft’s aging Navy-proprietary military specification architecture. “This contract was sold on an almost four to one [ratio] return on investment in terms of replacement versus maintenance,” he explains.

The company expects the FV-3000, which incorporates industrial components, to improve mean time between failure (MTBF) performance from around 11 hours for the current vertical display instrumentation group systems to more than 750 hours. That figure, he says, actually may be conservative. The company had projected MTBF at 1,500 hours in its discussions with Northrop Grumman. Field units have achieved MTBFs of more than 3,000 hours, Atac says.

However, the company also benefits from lower production costs because, although the system components are engineered specifically for the F-14B application, they are built for commercial applications in production runs in the millions of units.

Atac says that the FV-3000 readily could be configured for nonmilitary aircraft, although it has not yet sold the system commercially. The company’s commercial FV-2000 HUD already is in service aboard several business and commercial turboprop and jet aircraft, including the Gulfstream III and IV, Dassault Falcon 50, Lear 55, Cessna Citation 550 and the Beech’s King-class aircraft. Company officials say that the FV-2000 has been designed to accept and display symbology provided by enhanced vision sensor input, including forward looking infrared and millimeter-wave radar.