Designers of avionics equipment for U.S. Navy aircraft see obsolescence as their biggest obstacle in meeting the steady demand for upgrades and retrofits of existing aircraft. Their main weapon in this fight is to design each system with an open architecture.
By John McHale
The commercial avionics world took a big hit with the recent economic downturn, but military applications, especially for U.S. Navy programs, remain strong with old and new aircraft receiving the latest avionics systems based on open architectures to help combat component obsolescence.
“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.
“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 can be 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.
The U.S. Navy P-e Orion’s cockpit uses avionics from Rockwell Collins.
“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 lifetime-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 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 or 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.
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.
The P-8A Poseidon will replace the Navy’s P-3 Orion aircraft.
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 one 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 Collin’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.
EA-18G Growler avionics similar to F/A-18 F Super Hornet
Engineers at Honeywell Aerospace in Phoenix provide multiple avionics equipment to every variant of the F/A-18 program including the latest electronic warfare version of the F/A-18F Super Hornet–the EA-18G.
The Growler’s avionics are very similar to that of the previous model, the Super Hornet, says Greg Walker, manager, Military Crew Interface Systems, Honeywell Aerospace in Phoenix. What are unique to the Growler are the highly classified electronic intelligence and signals intelligence capabilities it has, he adds.
The EA-18G Growler electronic warfare aircraft, shown above, uses avionics based on those on the F/A-18F Super Hornet fighter-bomber.
The Growler is intended to be a replacement for the Navy’s EA-6B Prowler, Walker says. About 90 percent of the EA-18G including the avionics is the same as the F/A-18F with a lot of reuse of hardware and software, he says.
Avionics provided by Honeywell for the F-18 Growler includes a multipurpose 5-by-5-inch display and a backseat 8-by-10-inch display; advanced mission computer; H764G inertial navigation system/global positioning sensor (INS/GPS); a radar altimeter; antenna; indicator; air data transducers; and attitude heading reference system.
Fire Scout unmanned aerial vehicle avionics run by COTS computers
The Fire Scout unmanned helicopter from Northrop Grumman Aerospace Systems in Rancho Bernardo, Calif., uses commercial off-the-shelf (COTS) avionics for its flight control system.
The Fire Scout’s avionics are similar to those of manned systems, says John VanBrabant, Fire Scout domestic maritime business development manager at Northrop Grumman Aerospace. The main exception is with a redundant vehicle management system that has a vehicle management computer (VMC).
The unmanned aerial vehicle (UAV) is autonomous with a pre-programmed mission, VanBrabant says. The operator onboard ship or the ground can take over with the click of a mouse, but otherwise it flies on its own, he adds.
The U.S. Navy Fire Scout unmanned aerial system uses COTS avionics for its flight control system.
The flight control system is separate from the UAV payload system to enable payload changes without recertifying flight-control software, VanBrabant says. “The Navy has spent a lot of money on software development and wants to reuse as much as possible,” he adds.
Northrop Grumman designed the system to use as much COTS equipment as possible and use an open architecture to manage component obsolescence, VanBrabant says. The COTS vehicle management computer and other parts of the avionics are designed and produced by GE Intelligent Platforms in Charlottesville, Va., VanBrabant says.
In the case of Fire Scout, GE Intelligent Platforms also supplies a payload interface computer and the router/switch for each Fire Scout, explains says Peter Cavill, general manager of military & aerospace products at GE Intelligent Platforms.
“The VMC is a self-contained digital computer containing processors, memory, input/output circuits, and associated support circuits required to perform the flight control and vehicle management functions,” Cavill says. “The VMC is intended to function within a dual redundant vehicle management system (VMS), with one additional identical VMC operating in frame synchronous fashion, providing fault-tolerant control of UAV flight control and subsystems. Each VMC includes cross channel data links (CCDL) for the exchange of input signals.
“The Vehicle Management Computer (VMC) functions as the core computational and control element within a redundant control system on critical airborne platforms,” Cavill continues. “The VMC performs functions critical to flight safety including guidance and navigation, flight path, and vehicle stability control, and vehicle subsystems control.”
The compact VMC has six 3U CompactPCI slots, makes use of a single-board computer with a PowerPC 750/755 400-500 MHz processor, and support for the Wind River Systems VxWorks and Green Hills Integrity real-time operating systems (RTOSs), Cavill says.
The Fire Scout vehicle management computer (VMC), designed by GE Intelligent Platforms, has six 3U CompactPCI slots.
The computer also “interfaces with aircraft sensors, inceptors, actuators, and utilities/subsystems equipment primarily via high-speed serial data networks,” he explains. “The VMC performs the core flight control computing and failure monitoring functions while relegating the bulk of input/output interfacing to Remote Input/Output Units (RIU), which are also components of the VMS.
The UAV performs an autonomous landing through its UAV common automatic recovery system (UCARS) from Sierra Nevada Corp. in Sparks, Nev., VanBrabant says. At the end of its mission it will hover behind the ship, wait for a signal from the ship to land and use its instruments to determine the speed of the ship and its pitch and position in the water to make a proper landing, VanBrabant explains. These are all actions that a pilot would normally make using instinctive visual cues, VanBrabant says. With a UAV the system must be completely preprogrammed to perform those functions automatically, he adds.
According to the Sierra Nevada Web site “the UCARS-V2 was developed to provide day/night, all-weather, automatic landing and takeoff capabilities for unmanned aerial vehicle (UAV) systems operating from shipboard and/or fixed-base land environments. The UCARS-V2 is a direct descendent of the UCARS UPN-51 system that is in service with the U.S. Marine Corps Pioneer UAV. The UCARS-V2 consists of two primary components: a ground-based radar track subsystem and an air vehicle mounted airborne transponder subsystem. UCARS-V2 can also provide an automatic take-off capability for both fixed and rotary wing UAVs. UCARS-V2 has been integrated to perform automatic take-off and/or landing operations on numerous different UAS.”
The Fire Scout is flying off of a U.S. Navy guided-missile frigate–the USS McInerney–and performing naval operations in the Pacific Ocean and Caribbean Sea, VanBrabant says.
According to Northrop Grumman data sheets, the system is based on the “Schweizer Model 333 manned helicopter, and can autonomously take off and land on any aviation-capable warship and at unprepared landing zones in proximity to the forward edge of the battle area.”