Air Force News

F-117 testers evaluate real-time information capability

Released: 4 Aug 1998

EDWARDS AIR FORCE BASE, Calif. (AFNS) -- When a pilot configured an F-117 Nighthawk for a stealth flight during the Gulf War, the aircraft effectively became a manned cruise missile -- extremely capable of destroying a target, but unable to communicate with the outside world.

This limitation made it impossible to change the aircraft's pre-programmed mission plan. As a result, F-117s sometimes penetrated the densest, most lethal air-defense systems in the world only to find the target already destroyed, moved or obscured by weather.

Testers at the F-117 Combined Test Force at Plant 42 in Palmdale, Calif., are seeking to solve this problem with a new flight-test project designed to transmit real-time information into and out of an aircraft's mission computer. The combined test force is part of the Air Force Flight Test Center at Edwards Air Force Base, Calif.

IRRCA, or the Integrated Real-time Information into the Cockpit/Real-time Information Out of the Cockpit for Combat Aircraft flight test project, will greatly enhance the F-117's flexibility in combat, said Jim "J.B." Brown, lead IRRCA test pilot.

"A need exists on today's battlefield to provide a pilot with near real-time information on targets, weather and threats," Brown said. "So far, IRRCA has demonstrated the ability to provide real-time information and to automatically adapt to changing battlefield situations."

Initial go-ahead for the demonstration program was given in December. The IRRCA team completed the "real-time information into the cockpit" phase of the program June 30. The "real-time information out of the cockpit" phase is expected to begin next year.

The key to IRRCA is the integration of a real-time symmetric multiprocessor. This processor allows for onboard mission planning to take place in minutes. At 1.2 billion instructions per second, the new processor provides significantly faster computation times than ground mission planning, Brown said.

The processor will use the latest threat updates received inflight through the IRRCA system. As the aircraft receives threat updates from satellite broadcasts, a moving map displays new threats and the processor automatically evaluates the situation.

If the detected threat is expected to affect the mission, the processor will re-plan the F-117's route. The processor then gives the pilot an option to accept or reject the proposed route using threat exposure, flying time and landing fuel as decision factors.

A new color liquid crystal diode multifunction display provides interface between the pilot and the vehicle. This device can display a moving map, text messages, images and IRRCA system status. In addition to mission information, text and images also update the pilot on key events and weather.

Progress so far has shown the F-117 can react to mission updates, or target changes, and pop-up threats while remaining in a stealth configuration, said project manager Chris Greek.

In early July, encrypted messages were transmitted to a modified F-117 on simulated combat missions using a geostationary satellite and the aircraft's low-observable (stealthy) communications radio antenna system. These messages included threat updates, mission updates, text information for the pilot and target imagery.

Mission changes were transmitted to the F-117, providing information for the real-time symmetric multi-processor to re-plan the mission for a new target.

The mission update message was followed up by a text message and accompanying photographs. The pilot used these to verify the processor's planning results, enabling him to perform target study before attacking.

"The photographs were invaluable in the acquisition of targets," said Brown, who flew the test mission. "That's important since pin-point targeting is the F-117's forte."

The future of this technology may be used in other aircraft as well, according to Greek.

"IRRCA demonstrated that it will allow more efficient use of limited war-fighting assets," Greek said. "When it's fielded, commanders will have greater flexibility to react to changing tactical situations." (Courtesy of Air Force Materiel Command News Service)


* F-117 Nighthawk
* Air Force Materiel Command
* Edwards Air Force Base, Calif.