DARPA, U.S. Air Force Advance Automated Refueling

The goal of autonomous air-to-air refueling, a critical enabler for long-range, persistent unmanned strike and surveillance capability, moved closer to reality with the first autonomous probe-and-drogue refueling operation, achieved under a Defense Advanced Research Projects Agency (DARPA) program. A parallel U.S. Air Force program, focusing on boom-and-receptacle refueling, achieved autonomous formation flight with a tanker in the close-in contact position for an extended period of time.

Although both efforts derive from a DARPA unmanned combat air vehicle project, the technologies they develop could apply to manned refueling operations, as well. The Naval Air Systems Command (NAVAIR), for example, is interested in automation as a means of reducing refueling equipment wear and tear as well as operating costs. NAVAIR personnel have attended the flight demonstrations and design reviews of DARPA's Autonomous Airborne Refueling Demonstration (AARD) program. AARD technology could help make it possible to refuel manned platforms in a wider range of weather conditions and reduce the time interval required between receiving aircraft.

Both U.S. military programs depend on GPS receivers-augmented by inertial systems-to constantly measure the relative distance between the tanker and the aircraft being refueled. And both use data links to convey positioning data from one aircraft to the other.

The DARPA effort focuses on the probe-and-drogue style of refueling, where a pipe-like structure off the centerline of the receiving aircraft's nose connects with a 32-inch-diameter basket dangling at the end of a hose extending out from the tanker. In two series of attempts-three tries each-on Aug. 30, 2006, a specially configured NASA F/A-18 connected twice with a B707-300 tanker aircraft. (No fuel was exchanged during these tests.) The first connection lasted 10 to 15 seconds; the second lasted about 1 minute and 15 seconds. Five minutes is the goal for replenishing these small aircraft.

The AFRL initiative, known as the Automated Aerial Refueling (AAR) program, focuses on boom-and-receptacle refueling, which puts a premium on highly accurate formation flight with the larger tanker aircraft after the initial connection has been made. In a series of tests in August 2006, AAR's specially configured Learjet was able to hold the contact position, within an approximately 5-foot "box," for 23 consecutive minutes through two full orbits with a New York Air National Guard KC-135. (No physical connection was possible, as the business jet lacks an air refueling receptacle.)

The DARPA program uses a double-differenced relative GPS solution to provide precise relative positioning between the tanker and the receiving aircraft, explains USAF Lt. Col. Jim McCormick, the DARPA program manager. Sierra Nevada Corp. (SNC), the project integrator, feeds the raw GPS output from standard GPS receivers into tracking and control algorithms. The company's proprietary implementation is able to select from among several measurement techniques, including GPS real-time kinematic carrier phase tracking.

The DARPA program uses a commercial, fixed-frequency data link that operates with about 30-Kbit/s throughput and latencies in the 10s of milliseconds. No GPS, however accurate, could provide precise alignment between probe and drogue, McCormick explains. Because the drogue is swinging freely at the end of a long, flexible hose, the tanker's GPS cannot know its exact position. For this reason, the navigation equipment package in the receiving aircraft is also coupled to an optical tracker, a digital video camera fixed in the cockpit. "We use the relative nav system to tell the tracker what area to search," McCormick explains. The tracker essentially "looks for the dark circle in the center of the drogue [basket]." The additional sensor augments the navigation solution and provides a direct measure of drogue position. Total accuracy-including sensor and control error-is roughly 1 foot (0.3 m).

Over the next six months, DARPA plans eight more flights to further refine the system. McCormick also expects to push the performance envelope by testing the technology-mainly through simulation-in greater levels of turbulence, in decreased visibility and at shorter tanking intervals. He also wants to try making the refueling connection while the tanker is turning, vs. plugging in during straight and level flight. "I'd like the tanker to be able to do whatever it needs to be doing and still be able to do the plug," he says. The program also is developing a drogue motion compensation algorithm, which will increase autonomous refueling reliability in more challenging conditions by anticipating the motion and position of the drogue. -Charlotte Adams

Counter-MANPADS Initiatives Advance

Despite the absence of a clear public policy consensus and concerns about equipage costs, the effort continues to develop a system to defend commercial airliners against shoulder-fired, surface-to-air missiles, known as man portable air defense systems (MANPADS). While aircraft-mounted systems developed by Northrop Grumman and BAE Systems have entered Phase 3 of the U.S. Department of Homeland Security's Counter-MANPADS program, other efforts continue, including Raytheon's Vigilant Eagle, a ground-based airport protection system, and the development of laser technology that promises to make MADPADS systems more affordable.

In August 2006 Northrop Grumman and BAE Systems received Phase 3 contracts to implement their respective systems on test aircraft. Under a $55.4-million agreement, Northrop will produce 12 of its Guardian Counter-MANPADS systems, nine of which will be installed on MD-10 cargo aircraft that operate in regular service. Company officials displayed the first Guardian system installation on a commercial widebody aircraft, a FedEx MD-10, at Dulles Airport on Sept. 12, 2006. The FedEx aircraft will collect data on the Guardian system, which will also undergo maintenance and reliability checks, "basically to see how it works in the commercial environment," says Jim Pitts, president of Northrop's Electronic Systems sector. Guardian, which also has been tested on MD-11 and Boeing 747 platforms, uses a fuselage-mounted pod that contains four missile warning sensors, an AAQ-24(V) processor, a Viper laser pointer/tracker, and a laser beam to jam heat-seeking missiles.

Under a parallel, Phase 3 program, BAE Systems will further flight test its JETEYE system on board an American Airlines 767. The company also will equip an ABX Air cargo aircraft operated by DHL and perform a "suitability evaluation" to test the system on an in-service aircraft, says Steve duMont, business development director for the commercial aircraft program. But, he adds, "the real test will be when it's flown on a passenger airliner, because the concept of operation is different between cargo airlines and passenger airlines."

Based on the Army's advanced threat infrared countermeasures system, JETEYE uses four electro-optical missile warning sensors, an infrared laser and a pointer/tracker installed as a jam head on the belly of the aircraft, as well as avionics boxes along the side wall of the aircraft's cargo bay. It produces a high-power, multiband laser that, duMont says, "puts a lot of infrared energy into the front end of the missile, which basically blinds the missile and causes it to fly harmlessly away from the protected airplane."

Both BAE Systems and Northrop Grumman say their systems will cost less than $1 million, including installation, which is a requirement of the DHS program.

Other efforts could affect the counter-MANPADS equation. One of these developments can be seen at the Center for Quantum Devices (CQD) at Northwestern University. The center has made progress on the design, material growth and production of a magnified diode laser, known as the quantum cascade laser (QCL), which could eventually be used for missile defense and protection from MANPADS (see Air Safety Week, Sept. 11, 2006). Diode lasers, which are common in everyday products such as CD and DVD players, are compact and low cost. The center has increased the output and power conversion efficiency of QCLs and aims to achieve continuous output of 10 watts or more, which could be useful in onboard anti-missile equipment. Visit www.baesystems.com, www.northropgrumman.com and www.raytheon.com. -Andrew D. Parker

Traffic Surveillance
Rockwell Collins has unveiled its TSS-4100 traffic surveillance system for business and regional aircraft. The unit combines traffic alert collision avoidance system (TCAS II) and Mode S transponder functions in a single line replaceable unit (LRU). The TSS-4100 also supports emerging automatic dependent surveillance-broadcast (ADS-B) applications, such as cockpit display of traffic information (CDTI), traffic information service-broadcast (TIS-B), and decision support functions, including merging, sequencing, separation assurance and surface operations. The TSS-4100 also will support FAA's Next Generation Air Transportation System (NGATS), Europe's Single Sky initiative and other programs. The system, which replaces the existing 4-modular concept unit (MCU) TCAS configuration, consists of the receiver/transceiver LRU and a combined TCAS/Mode S antenna. According to David Wu, director of flight deck systems marketing, the TSS-4100 is derived from the traffic module of Collins' configurable integrated surveillance system (CISS-2100) for the B787. But the CISS-2100 also has weather processing and terrain awareness warning system (TAWS) functions not included in the TSS-4100. Wu notes that in business and regional aircraft, LRU size is an important consideration. The B787 configuration is 8 MCU wide, he says, which would have limited market acceptance of the TSS-4100 in those smaller aircraft. Rockwell Collins says it has multiple customers for the system. Visit www.rockwellcollins.com.

Wireless Radio
Shared Spectrum Co. of Vienna, Va., has completed a technology demonstration as part of Phase 3 of the neXt Generation Communications (XG) program, which aims to achieve 10 times more radio frequency (RF) spectrum with minimal installation time, as well as simplify RF spectrum planning, management and coordination. Funded by the Defense Advanced Research Projects Agency (DARPA) and managed by the U.S. Air Force Research Laboratory, the XG program is developing system concepts for military line-of-sight radios. The demonstration featured six mobile IEEE 802.16-based XG radios operating in the same spectrum as a package of fixed, instrumented military and commercial legacy radios. A wide area instrumentation system recorded the XG radio and legacy radio performance. According to Shared Spectrum, the exercises show that XG radios cause no harm to existing frequencies, allow the formation of additional communications networks and can operate in the presence of jamming. Visit www.sharedspectrum.com.

Military Communications
Forecast International predicts that sales of airborne communications equipment in the U.S. military market will reach $2 billion over the next decade. In a new study the company projects $1.34 billion in sales over the next five years, and another $687 million in sales from 2011-2015. The report also anticipates that the military's tactical targeting network technology (TTNT) data link will account for $439 million, or 21.6 percent of the total, over the next 10 years. Programs related to the multifunctional information distribution system (MIDS) will be worth $415.6 million over the same time span, or 20 percent of the market. Another initiative, the Air Force's RF Sensors and Countermeasures Project, will account for around $294 million, or 14.5 percent of the total, according to the study. Visit www.forecastinternational.com.

Frisbee UAV
Triton Systems of Chelmsford, Mass., has received a U.S. Air Force contract to develop a "modular disc-wing urban cruise munition," an unmanned air vehicle (UAV) intended to find and attack combatants in urban environments. The multiple explosively formed penetrator (MEFP)-armed "Lethal Frisbee UAV" will have 3D maneuverability and send reconnaissance, pursuit and precision fire information to aircraft and ground-based units. According to the Air Force, multiple Frisbee UAVs could be launched from aircraft or the ground in munitions dispensers or a device resembling a skeet launcher. Both remotely operated and autonomous modes would be provided through wireless links to tactical data systems. The military says the Frisbee UAVs would provide access to hostiles hidden in upper-story buildings or concealed behind objects, while limiting the hazard to bystanders or friendly forces. Visit http://dodsbir.net/selections/abs061/afabs061.htm.

Surveillance Radar
Northrop Grumman has completed the first flight of the Global Hawk's new airborne surveillance radar. The test flight, under the Multiplatform Radar Technology Insertion Program (MP-RTIP), was conducted during the last week of September on a high-altitude Proteus test aircraft (above). The MP-RTIP sensor for the unmanned aerial system was tested in moving target indicator (MTI) and synthetic aperture radar (SAR) modes. The radar also will include a large antenna, wide area surveillance (WAS) sensor, which will provide improved air-to-ground surveillance, precision air tracking, cruise missile defense and other modes intended to take advantage of the larger antenna. Initial WAS sensor tests aboard an EA-10A manned aircraft are planned for 2010. Northrop is jointly developing the radar with Raytheon. Visit www.northropgrumman.com.

GE Fanuc-Radstone Deal
In an agreement pending regulatory and shareholder approval, GE Fanuc Embedded Systems has agreed to acquire Radstone Technology plc, the UK-based supplier of embedded computer products, for £130.4 million pounds (about $245 million). According to GE Fanuc, Radstone's rugged, commercial off-the-shelf (COTS) computers, subsystems and supporting software products will complement its line of embedded boards and systems. Headquartered in Towcester, UK, Radstone Technology is the parent company of Radstone Embedded Computing, which includes ICS Sensor Processing, Radstone Digital Processing and Octec, an image processing provider. Following approvals, GE Fanuc anticipates finalizing the acquisition in the first quarter of 2007. Visit www.gefanuc.com/embedded and www.radstone.com.

Tailored Arrivals
Boeing, NASA and their industry partners have begun the first U.S.-based operational trials of an advanced air traffic management (ATM) concept known as "tailored arrivals," which the manufacturer says will save significant amounts of fuel for aircraft while landing. Boeing completed tailored arrival trials at San Francisco International Airport on Sept. 6, 2006, including 17 flights with United Airlines B777-200s. According to Boeing, the San Francisco tests reflect results from similar trials in Australia and the Netherlands over the past two years, which indicate fuel savings of approximately 60-120 gallons (227-454 liters) per flight. In addition to United Airlines, the manufacturer is working with NASA's Ames Research Center, FAA's Oakland air route traffic control center, Northern California terminal radar approach control, Lockheed Martin and Sensis Corp. on the project. A second group of tests is planned for late October with B777s and B747s. Visit www.boeing.com.

Display STC
FAA has issued a supplemental type certificate to Innovative Solutions & Support Inc. for installation of the company's 10-inch Cockpit/IP flat panel display in the Pilatus PC-12. Modifications are conducted through Boise, Idaho-based Western Aircraft and Epps Aviation of Atlanta, Ga. visit www.innovative-ss.com.

Data Link
L-3 Communications division, Communication Systems-West (CS-West), has conducted preliminary flight tests of an Internet protocol (IP) -enabled, wideband multiplatform common data link (MP-CDL) system. The company tested the system using an airborne MP-CDL hub, which transmitted real-time video and voice data to two ground-based spoke terminals, mixing video streams from an L-3 Wescam 12DS 200 camera and a cockpit webcam with voice over Internet protocol (VoIP) phone traffic. According to CS-West, data rates reached up to 137 Mbits/s on the outbound link and up to 67 Mbits/s on the inbound link. Two KC-135 aircraft are being fitted with MP-CDL systems in preparation for additional network centric flight demonstrations, including point-to-point, air-to-air, multiple hub, and hub-handoff functions. Visit www.l-3com.com.

Mixed-Signal Technology
BAE Systems has obtained a $6-million contract from the Defense Advanced Research Projects Agency (DARPA) to continue researching mixed-signal technology, which the company says will increase the performance of military electronics while significantly reducing size, weight and power consumption. Under the agreement, researchers will further develop the technology by integrating selected photonic components into the complementary metal oxide semiconductor (CMOS) process, increasing the performance of silicon computer chips. The research agreement is associated with Phase 2 of DARPA's Electronic and Photonic Integrated Circuits (EPIC) program. Visit www.baesystems.com.

JTRS Flight Demo
Lockheed Martin has flight tested its brand of network centric capabilities as part of the competition for the airborne, maritime and fixed station (AMF) component of the U.S. military Joint Tactical Radio System (JTRS) program. In a Sept. 8, 2006, live demonstration, airborne nodes linked an Air Force F-16, an Army helicopter and a T-39 Sabreliner-intended to represent an unmanned air vehicle (UAV)-into combat-driven scenarios. Ground and air nodes interfaced in a mobile ad hoc network, using the ground mobile radio (GMR) wideband networking waveform, soldier radio waveform (SRW) and legacy Link-16 communications. Observers on the ground watched real-time video from the aircraft and communicated in real time via new and legacy systems. A request for proposals is expected in October 2006, followed by contract award next March. Visit www.lockheedmartin.com.

Electronic Attack
The U.S. Navy has awarded $22 million to Northrop Grumman for additional airborne electronic attack (AEA) system spares for the EA-6B Prowler. The order, part of the improved capability (ICAP III) program for the fighter, follows a $73-million Navy purchase in March 2006 of four complete AEA systems, a partial system and spares. The ICAP III is a fifth-generation system that includes an ALQ-218 receiver subsystem. Northrop's Integrated Systems sector plans to complete production work on the systems by December 2009. Meanwhile, Boeing has delivered the first EA-18G aircraft to the U.S. Navy's test site at Naval Air Station Patuxent River, Md. The first EA-18G is scheduled to join the Navy's fleet in 2008. Visit www.northropgrumman.com.

Weather Radar
Singapore Airlines has selected the Honeywell RDR-4000 next generation windshear/weather radar system for its fleet of 19 new Boeing 777-300ERs. The radar scans an aircraft's horizon at different tilt angles to supply a 3D digital image of weather and terrain ahead. The RDR-4000 uses an internal terrain database, adapted from Honeywell's enhanced ground proximity warning system (EGWPS), to remove ground clutter. Honeywell plans to begin delivering the RDR-4000 systems in September 2006. Visit www.honeywell.com.

In-Flight Entertainment
Jetstar, an Australian carrier, has chosen digEcor's digEplayer XT for its new Airbus A330-200s and existing A320s. A portable audio/video in-flight entertainment (IFE) system with an 8-inch screen, the digEplayer XT is preprogrammed with movies, TV shows, videos, music and games. According to digEcor, Jetstar customers will begin using the unit in November 2006, with retrofits for the A320 fleet scheduled for January 2007. Visit www.digecor.com.

Flight Management
German carrier, Lufthansa, has picked the Topflight flight management system (FMS) for its fleet of new Airbus A340-600s. Developed by Thales and Smiths Aerospace, the system uses dual high-speed processors and features large memory capability, a liquid crystal display (LCD) interface and several unique software functions. Visit www.thales.com and www.smiths-aerospace.com.

NVG-Equipped Helicopter
Jet Source, a Carlsbad, Calif.-based provider of avionics modifications, has completed equipment upgrades on the first of four San Diego Police Department Eurocopter AS350 B3 helicopters. The modifications include night vision goggle equipment and the installation of a FLIR 8500 thermal imaging system, Avalex moving map and a customized radio suite. Jet Source also equipped the AS350 with a Garmin GNS 430 com/nav/GPS unit, SL30 com/nav and GTX330 transponder, as well as a Wulfsberg RT5000 multiband transceiver, Sagem 8-inch primary flight display and Avidyne traffic alert collision avoidance system (TCAS). Visit www.jetsource.com.

Data Monitoring
Neos, an Italian charter airline, has selected the aircraft flight analysis and safety explorer (AirFASE) for its fleet of B737NG and B767-300ER aircraft. AirFASE is flight data monitoring software developed by Teledyne Controls and Airbus. The software will assist Neos technicians with flight operations, safety management and maintenance programs, as well as aircraft monitoring. The system also will provide flight operations trends, risk precursors and preventative/corrective actions. Visit www.teledynecontrols.com and www.airbus.com.

A-10A Displays
The U.S. military has awarded $16 million to Raytheon Technical Services Co. for 85 multifunction color displays (MFCDs) for Air Force Reserve and Air National Guard A-10As. The units will replace the aircraft's existing television monitor. The MFCD allows improved control of the A-10A's targeting pod, displaying real-time data from the situational awareness/enhanced position reporting location system (EPRLS) data link on an embedded digital moving map. Compatible with night vision system imagery, the MFCD also stores multiple map scales and images. Visit www.raytheon.com.

Electronic Flight Bag
Air France has chosen Boeing Class 3 electronic flight bags (EFBs) for its fleet of B777s. The Class 3 EFB will be integrated into the avionics systems of 42 B777s in service and 13 on order. The EFB uses open architecture software developed by Boeing and Jeppesen to give airlines the ability to add their own documents and third-party applications. Visit www.boeing.com.

Night Vision
The U.S. Coast Guard has contracted EFW Inc. to provide an aviator's night vision imaging system/head up display (ANVIS/HUD) for its HH-65 and HH-60J helicopters. The multiple contacts, valued at $815,000, will boost the abilities of the helicopters to perform search and rescue, border patrol and vessel identification missions. Visit www.efw.com.

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