U.S. Navy avionics systems integrators embrace open architectures to combat parts obsolescence

Special report -- Designers of avionics equipment for U.S. Navy aircraft see obsolete electronics as their biggest obstacle in meeting the steady demand for avionics upgrades and retrofits of existing aircraft. Their main weapon in this fight is to design each system with an open architecture.

By John McHale

Designers of avionics equipment for U.S. Navy aircraft see obsolete electronics as their biggest obstacle in meeting the steady demand for avionics upgrades and retrofits of existing aircraft. Their main weapon in this fight is to design each system with an open architecture.

The commercial avionics world took a big hit with the recent economic downturn, but military applications, especially for U.S. Navy avionics programs remains strong with old and new aircraft receiving the latest avionics systems based on open architectures to help combat obsolete electronic components. See related article entitled Fire Scout unmanned aerial vehicle avionics run by COTS computers.

"The military avionics market is strong for Honeywell Aerospace, however it will be a good year before the commercial market turns around," says Greg Walker, manager of military crew interface systems at Honeywell Aerospace in Phoenix. Money for new programs is fairly secure, but the real meat of the business will come from upgrading existing airplanes in commercial and military sectors, he adds.

This also means more obsolescence issues as the program development life for most military flight systems is measured in years, where commercial-off-the-shelf (COTS) technology goes obsolete in as little as 18 months, Walker says. "The F-22 is shutting down and the Air Force has no new birds," which forces military to keep relatively old aircraft flying even longer, Walker says.

Managing obsolescence

"Obsolescence management kills us," Walker says. On the avionics side the way to go is with an open systems architecture to swap out parts easily that are no longer being made, Walker says. One method to combat obsolescence is by making a lifetime buy of a component when a vendor announces that they making it obsolete, Walker says.

One problem with this method is the length of military development cycles, which anywhere from four to seven years. By the time the system is ready for deployment, its electronics components often are obsolete, which forces systems integrators to make costly redesigns.

"We have two major processor card lines -- one for general-purpose processing and one for dedicated display graphics generation," Walker says. "Each is upgraded every few years to stay ahead of the industry's obsolescence cycle. Both of these processor lines are sustained and upgraded by Honeywell to prevent cost to the customer for significant life-time-buy expenses."

Honeywell experts design their company's main processor boards in house, rather than buying them from someone like Curtiss-Wright Controls Embedded Computing or GE Fanuc Intelligent Platforms, Walker says.

"We do not sell these boards to anyone but ourselves," Walker says. "We make the boards and they run on Pentiums, PowerPCs, etc.," depending on the system.

Another big cost factor in avionics development is managing software, Walker says. Whenever a piece of hardware changes, its software may have to be re-certified rewritten, which is costly. This is why many engineers always push for hardware to be independent of software in open architecture avionics systems, he says.

P-8A Poseidon

Honeywell engineers are taking the open architecture approach on the avionics for the Navy's P-3A Poseidon anti-submarine warfare and long-range maritime patrol jet, which will replace the P-3 Orion turboprop sometime in the next decade, Walker says.

Boeing is the prime contractor for the P-8A, which also is for anti-surface warfare, intelligence, surveillance, and reconnaissance. The P-8A is based on the Boeing 737 airliner, for which Honeywell also provided the avionics, Walker says. "We took the 737 avionics and militarized it for the Navy." Honeywell engineers did something similar when they took ruggedized avionics designed for business jets for use in NASA's Orion space program.

Militarization includes meeting Mil-STD 881 and other requirements such as electro-magnetic interference (EMI), Walker says. There is a lot of complicated electronics in a tactical aircraft such as the P-8 and it needs proper shielding, he adds. Honeywell engineers also dimmed cockpit instruments to help enable P-8 pilots to wear night vision goggles. Honeywell also stabilized P-8 avionics to withstand strong shock and vibration.

Beyond meeting these technical standards, Walker declined to detail more specifically how the avionics were militarized.

Honeywell avionics on the P-8A include cockpit displays; display processing; air data inertial reference unit (ADIRU), and an enhanced ground proximity warning system (EGPWS), according to a Honeywell data sheet.

The ADIRU gyros have automatic gyro/accelerometer calibration, and have a mean-time between failure rate of 250,000 hours. Honeywell's displays for the P-8A include three B737-800 displays; three Modified B737-800 displays with video; two B737-800 displays with software modules; two modified B737-800 EFIS Control Panels (EFISCP); and two B737-800 remote light sensors, Walker says.

Air traffic management

Engineers at Rockwell Collins in Cedar Rapids, Iowa, have upgraded the avionics on the Navy's P-3 Orion Maritime Patrol Aircraft and the E-2C Hawkeye to meet military and civil air traffic control requirements called communication, navigation, and surveillance for air traffic management (CNS/ATM), says Harry Oakley, principal marketing manager for special mission and search and rescue aircraft at Rockwell Collins.

Navy aircraft must be able to fly anywhere in the world, so the P-3 and E-2C satellite and gyro navigation systems must meet global air traffic control guidelines. For this effort Rockwell Collins engineers not only updated systems, but also the common display units (CDUs). "The CDU is a key pad with a window to see what you are entering," Oakley explains.

The Navy also plans to make incremental improvements to P-3 avionics flight management systems and displays, says Mike Fralen, program director and market segment lead for maritime surveillance aircraft at Lockheed Martin in Eagan, Minn. Lockheed Martin is the prime contractor and systems integrator on the P-3 program.

Even when the P-8A officially takes over the main duties of the P-3, the Navy will still use the aircraft for surveillance and patrol applications, Fralen says. Other U.S. Agencies such as the National Oceanic and Atmospheric Administration (NOAA) and Customs and Border Protection Agency will use versions of the P-3, Fralen says. "The P-3 will continue flying for a long time," Lockheed Martin's Bell says.

The biggest users of the P-3 for the next few decades will be foreign militaries, who will also require upgrades to the avionics systems, Fralen says. The key to all future avionics upgrades designs is making sure the systems are based on an open architecture that embraces COTS technology and standards, Oakley says.

"We're even more into COTS with the tactical computers in the back of the airplane," Fralen says. Cost wise there was really no choice, and to battle obsolescence Lockheed Martin makes sure open architectures designs are used, he adds.

At Rockwell Collins their open architecture approach is called MOSA or modular open systems architecture, where avionics systems are designed in modules that are independent of the whole system to enable replacements and upgrades that do not affect the entire avionics suite.

"Our displays on the P-3 are a 5X5 called the MFD-255, with on each side," Oakley says.

The CDU-7000 features a color active matrix liquid crystal display (AMLCD), Power PC processor, and 3U Compact PCI compatible circuit cards. The unit consolidates control of communications, navigation, weapons management, and defensive aids into a central point that includes the aircraft's flight management functions. The CDU-7000 also has a powerful processor, ARINC 739 capability (required for meeting future Global Air Traffic Management [GATM]), and a rugged keyboard for turbulent missions.

The CDU 7000 replaced the Rockwell Collins CDU 800 in the E-2C cockpit, Oakley says. They also added ARINC 429 and MIL-STD 1553 databus interfaces.

The display on the co-pilot's side of the E-2C is the Rockwell Collins MFD-2912 9-by-12-inch display, which enables the flight crew to see tactical data from operators in the back, Oakley says. This enhances crew situational awareness in the cockpit and has better performance and safety.

On the P-3 Rockwell Collins also added new radios and tactical data links as part of an obsolescence upgrade, Oakley says. The upgrade replaced dual high frequency (HF) radios and Link 11/TADIL-A tactical digital data link converters with a 400-Watt HF-121C HF transceiver, known as the AN/ARC-230, and the MX-512PA Link 11/TADIL-A Modem, known as the AN/ASQ-130(V). DRS Communications Co. in Wyndmoor, Pa., is a subcontractor to Rockwell Collins for the Link 11/TADIL-A modems. The contract also includes options to install the Rockwell Collins's HF messenger e-mail capability.

Right now there are no plans to go to a complete glass cockpit in the P-3, Oakley says. Currently "the engine instruments for the P-3s are still round dials. We will have to see how it plays out in the P-3 program, if the Navy wants to spend the money increase the size of the glass, he says. "If they do it will bring more situational awareness into the cockpit and make the displays easier to read," he notes.

"I'd sure like to see the P-3 become a completely glass cockpit, but its probably not going to happen as the Navy wants to end-of-life it in 2019," Fralen says.

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