Military Embedded Systems

Avionics upgrades enhance situational awareness for military pilots


March 05, 2014

Sally Cole

Senior Editor

Military Embedded Systems

Military avionics retrofits to aircraft such as the B-1 Bomber are leveraging powerful commercial processors and high-speed networking in a distributed architecture to enable future capability upgrades. Meanwhile, safety concerns related to degraded visual environments are driving synthetic vision designs for rotary wing platforms.

Avionics upgrades currently underway on the U.S. Air Force’s B-1 bomber fleet are integrating glass cockpits featuring larger, full-color displays and moving maps – supported by a Gigabit distributed Ethernet network and two types of datalinks – to significantly enhance communications and situational awareness within the battlespace.

The Boeing (Oklahoma City, OK; upgrade modification for the B-1, known as the Integrated Battle Station or IBS, is the most extensive mod program in the B-1’s history and, among other things, replaces 25-year-old avionics. The IBS modernization program essentially merges three separate development programs – Vertical Situational Display Unit (VSDU), Fully Integrated Datalink System (FIDL), and Central Integrated Test System (CITS) to upgrade the B-1’s front and back cockpits.

For perspective on just how massive this upgrade is, according to Boeing, the IBS kit consists of roughly 2,400 line items, which equates to about 16,000 parts. This mod requires removal of both front and back cockpit seats, redoing all wiring and consoles, installing the new displays and controls, and then testing the aircraft (see Figure 1).


Figure 1: One major upgrade for the B-1 integrates a modern datalink communication network to enable real-time communication with other aircraft, ground stations, and allied forces. Photo courtesy of Boeing.

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“Boeing’s responsibility under the IBS contract is to produce kits that go into the B-1s. Then the Air Force 76th Aircraft Maintenance Group installs our kits at Tinker Air Force Base in Oklahoma, in two hangars, which can hold two aircraft per hangar,” says Rick Greenwell, B-1 program director for Boeing. It took nearly 10 months to complete the first B-1 mod, but the goal is to reduce the install time to seven months.

New avionics hardware and software

Boeing’s mod brings four new processors onboard the B-1: two each for its front and back cockpits. “These processors are equipped with eight slots for PowerPC single-board computers, but the slots aren’t all populated, which leaves room for growth,” explains Dan Ruder, B-1 strategic development and advanced programs manager for Boeing. “The processors’ key function is to provide display processing for the new moving map capability, while a dedicated processor handles all datalink processing.”

For its Real-Time Operating System (RTOS), the aircraft runs Integrity from Green Hills Software. “Each processor communicates over Gigabit Ethernet on the aircraft now,” Ruder says. “Previously, the B-1 used a federated architecture, but replacing it with a distributed architecture onboard allows us to easily add new capabilities in the future.”

To make it easier to maintain the system, the B-1 is shifting from Jovial programming language to C and C++, according to Greenwell.

The B-1 now also has two types of datalinks: Link 16 and a beyond-line-of-sight datalink satellite system. What do the new datalinks enable? Fast digital data uploads onto a computer; reprogramming an entire weapons load with a new set of coordinates now simply requires a mere two or three keystrokes. In the past, as Greenwell describes it, the process involved “a voice conversation and ‘fat fingering’ in at least 200 keystrokes and then verifying it.”

Another big feature of the FIDL upgrade is a distributed architecture, which means data can be shown on any display within the aircraft. Collaboration tools within this architecture also enable the aircraft’s crew “to look at each other’s displays with a ghost cursor, so if one weapons system officer wants to see what someone else is looking at, he can see a ghost cursor over on his own display – this allows the crew to collaborate and ensures they’re all looking at the same thing,” Ruder says.

Future upgrades “may involve integrating improved datalinks or radar or sensors. If we decide to improve systems, the new IBS architecture will allow us to incorporate them into the B-1 more readily,” Greenwell says.

B-1 pilots get new displays

Old-style monochrome displays didn’t have much to offer in processing or display capabilities, which meant the B-1’s front cockpit pilots lacked situational awareness about what was occurring around them in the battlefield. The “backseaters,” however, had excellent situational awareness and were able to direct the front cockpit pilots where to fly, explains Ruder.

The VSDU portion of the upgrade brings “much larger displays that can show significantly more information,” says Karl Shepherd, director of marketing and strategic development for Rockwell Collins (Cedar Rapids, IA;, Boeing’s long-time partner on the B-1. A big overall upgrade trend in displays is to go to larger sizes. “About 15 years ago, 10 x 8-inch displays were emerging as the largest size. Now, we’re making 9 x 15-inch displays for cockpits,” Shepherd says.

Demand for increased display sizes and processing improvements is being driven by the desire to host more software applications. “This is, in turn, driven by connectivity from aircraft to aircraft, sharing and exchanging information,” he explains. “Once the aircraft are connected together they can exchange information in a digital fashion and interact with it.”

Now, with moving maps and displays in the front cockpit, “the B-1 pilots’ situational awareness is improved and they can actually interact with the offensive software. This unloads some of the workload from the backseaters to the frontseaters,” Greenwell says.

The new color displays provide “better cuing about where threats are, such as ‘friendly’ blue force or ‘enemy’ red force tracking, and with the full moving maps they know exactly where they’re going and have some control of their navigation,” Ruder notes. “Now the pilot and copilot have the ability to have full control of their navigation, but the primary responsibility for navigation is still with the offensive system officer.”

Diagnostics upgrade

Before the CITS upgrade of the diagnostics system, the B-1 had an antiquated Light Emitting Diode (LED)-type three-line display and could only monitor three parameters at a time, which were displayed in voltage units that required using a paper chart to plot it out and convert it to engineering units. Now, Boeing officials say that as many as 24 of 20,000 different parameters can be simultaneously monitored – everything from engine temperatures to hydraulic pressures to flight controls – whether the aircraft is inflight or on the ground.

“With the new display, everything is converted to engineering units so the maintainer doesn’t need to do the paper chart lookup anymore,” Ruder notes. “We’ve also given them display pages so they can view all of the important information for a specific system.” Once the entire upgrade on the B-1 is complete, “it’s a brand new aircraft to the flight crews,” Greenwell says.

CNS ATM mandates, more glass cockpits

While the B-1 avionics mod created an essentially new cockpit for the pilots, other military avionics upgrades are being driven by two primary factors.

“The first factor is related to getting access to civil airspace, so they’re trying to meet Communication, Navigation, Surveillance/Air Traffic Management (CNS ATM) mandates to ensure they won’t be denied or get less-than-desirable access to airspace,” Shepherd says. “This is a big issue and we’re responding to it with our upgrade programs.”

The second factor is simply that older aircraft tend to have analog or federated instruments. “As maintenance and sustainment costs become prohibitive, we’re seeing upgrades to replace those legacy electromechanical instruments with either a full-glass or partial-glass cockpit, which lowers sustainment and maintenance costs and gives them a significant increase in capabilities,” Shepherd adds.

Several other notable military avionics upgrades are also occurring now, primarily on the fixed-wing side. For example, Rockwell Collins engineers are working with the U.S. Air Force on ongoing tanker upgrade programs that include the KC-135 and KC-10, as well as multiple customers for C-130 upgrades around the world (see Figure 2).


Figure 2: C-130 cockpit before (left) and after upgrade (right). Photos courtesy of Rockwell Collins.

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Honeywell Aerospace (Phoenix, AZ; is also working on avionics upgrades of “everything from F-16s and F-15s to [rotary wing platforms such as] OH-58s, CH-47s, [to transport aircraft like] C-130s, and even older aircraft like P-3s and B-52s around the world,” notes Bob Olson, director of Military Integrated Avionics for Honeywell Aerospace.

Many military rotary-wing platforms are being recapitalized today and replaced with new aircraft that have upgraded avionics suites and glass cockpits. Next up for these platforms will be new avionics capabilities that focus on safety challenges.

Degraded visual environments

One of these safety features that hasn’t evolved into an upgrade yet, but is likely to in the future, addresses the challenges of operating in degraded visual environments for rotary-wing military aircraft. Both Rockwell Collins and Honeywell Aerospace are working on approaches to deal with these challenges.

“When helicopters come into a landing zone and kick up either dust or snow, pilots want a way to increase situational awareness and reduce their workload by having information presented on glass cockpit displays to help them understand what the aircraft is doing relative to the terrain and the environment around them,” Shepherd says.

Honeywell recently demonstrated a system with the U.S. Defense Advanced Research Projects Agency (DARPA), in which they operated in a degraded visual environment using a Blackhawk. They call this capability “Synthetic Vision Avionics Backbone (SVAB),” and it uses a “sensor impartial” approach with multiple sensors and databases to create an integrated 3-D scene for pilots.

“With SVAB, the pilot can look at a synthetic environment of obstacles to help land safely,” says Olson. “Helicopters are the equivalent of off-road vehicles because they land in all kinds of conditions, so this feature is designed to enable much better situational awareness. It’s not in production yet – we’re at [Technology Readiness Level] TRL 6 now – but it’s the kind of thing you might see in the future.”


Figure 3: Degraded Visual Environment Pilotage Systems (DVEPS) is fully compatible with the Common Avionics Architecture System on the U.S. Army’s MH-47G and MH-60M helicopters, as well as many other tactical avionics systems. Photo courtesy of Rockwell Collins.

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Rockwell Collins is also focusing on this area and recently completed a DARPA program to develop an SVAB that will fuse landing zone sensor data with terrain and obstacle data to produce an integrated 3-D view of the operational environment. “We’re in Phase I of the U.S. Army’s Degraded Environment Pilotage System (DVEPS) program, in which they’re taking technology developed by DARPA and Rockwell Collins and transitioning it into their fleet of helicopters,” Shepherd says (see Figure 3).

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