As they continue to develop cockpit improvements across a wide range of technologies, manufacturers are focusing on what it takes to put all of the components together in a cockpit in the right combination to make the experience as easy for pilots as possible.

Indeed, the input of pilots is critical when testing new technologies or upgraded equipment to put into any military aircraft, both fixed and rotary wing. Lockheed Martin, for example, makes careful use of an A-10 Systems Integration Lab (SIL) to perfect the cockpit of the plane for the Air Force, said Roger Il Grande, the company’s A-10 program director.

The process of introducing something to the cockpit begins with an idea for an improvement in the context of the requirements for that system, Il Grande said. The idea can come from the Air Force, Lockheed Martin or one of the integrator’s many partners. If the idea appears to have merit, Lockheed Martin kicks off a conversation with pilots and other experts, during which the ideas are discussed on paper to see if they generate sufficient interest.

Lockheed then begins use of the SIL to define the requirements for a new system.

“Early on in the process, even at a pre-systems requirements review, we will try to get a better understanding from the user as to what he is looking for in a final product,” Il Grande said. “The first utilization of the SIL is in the requirements definition process, which is way earlier than testing the final product. We will, in a lot of cases, do prototyping or mock-ups of what the end item is going to look like for the pilot and try to get his reaction by using the SIL.”

Pilots will enter the simulator as part of a cockpit review team, providing early feedback on the interpretation of the requirement and the conceptual solution to meeting the requirement, Il Grande said.

“We can now write in more accurate detail for what the requirement is and have that reviewed by the Air Force and the rest of the team, not only from a pilot’s point of view, but also for insight into how that requirement might affect others from, say, the maintenance perspective,” he added.

After getting the requirements right, the A-10 team would go through a design- review process to examine the best way to fulfill the requirements. Then the company moves into the designing phase, when software developers, for example, could start to develop code for the cockpit.

“The early input from the pilot leads you to how to define the requirements better, and how you hand off those requirements more precisely to the software developers. It just heightens the likelihood that you are going to get this thing right earlier in the process,” Il Grande said.

A new subsystem may be released to the SIL incrementally so that pilots and others can judge its effectiveness. Once complete, the cockpit-review team can meet again and fly some scenarios, provide feedback and still affect the development of the product.

“We pick the high-risk areas to show pilots, and we pick those at risk of rework and risk of preferences being different,” Il Grande explained. “We pick those areas with the pilots as to what we should be reviewing. We get that feedback and the code continues to be designed.”

Finally, the company integrates the pieces of a new subsystem into the SIL and enters into an integration and test phase, where it ensures everything works well together and meets expectations.

“There is an opportunity at that point in the systems-integration process to introduce the pilots one more time to the systems, trying as much as possible to leave time for feedback, so that you can prioritize and maybe have the opportunity to incorporate that feedback before the final test process,” Il Grande said. “Once we get that final test in the SIL, we expect that to run reasonably well. We have screened out mismatch issues in terms of requirements and preferences.”

Finally, the A-10 enhancements would go to flight test. Lockheed Martin would use its A-10 SIL to replicate any issues encountered in flight test to assist with any possible fixes.

Crashworthy Seats

Many of the subsystems added to fixed and rotary wing aircraft in recent years have involved improvements to the comfort and survivability of the pilot. One company in that field is Martin Baker, which manufactures cockpit seats for the F-35 Joint Strike Fighter and other military aircraft.

Martin-Baker’s new high-comfort crashworthy armored cockpit seats do not necessarily provide more ballistic protection than other products have in the past, but technological advancements have enabled the company to make such seats lighter, more comfortable and more affordable, according to Thomas Pavlik, the company’s U.S. business-development representative.

Crashworthy seats for rotary wing aircraft, such as the Black Hawk, have weighed more than 100 pounds in the past, but Martin-Baker has reduced the weight to 82 to 84 pounds, Pavlik said. Much of the effort in introducing improvements in helicopters goes toward reducing the weight of components, which makes the helicopter more maneuverable.

In addition, the military places a higher emphasis on comfort than it did previously.

“In the past, helicopter missions were thought of as two-hour missions,” Pavlik said. “That was the thought process when cushions were designed. Now we are learning in Afghanistan and Iraq that some of these people sit in that cockpit all day long. Some of these aircraft now have in-flight refueling, and their missions could be seven or eight hours before they even land again.”

Pilots cannot exactly walk around and stretch, Pavlik noted, so Martin-Baker developed a new set of cushions for the Joint Strike Fighter ejection seats and brought that technology over to helicopter seats to help make pilots more comfortable and less tired.

“When they are fatigued, their performance is degraded. That means they have a lower probability in accomplishing the mission as well as putting themselves as risk,” Pavlik said.

By introducing all of these changes in a cost-effective manner, Martin-Baker has been able to make the seats more affordable for the military as well, Pavlik added.

The Navy standardized on Martin-Baker ejection seats with the Navy Aircrew Common Ejection Seat, Pavlik added. Soon after the selection, the Navy decided to permit women to fly aircraft, as well as to increase the physical size limits for male pilots. Meeting that requirement involved using modeling and simulations to figure out how to eject smaller persons from the aircraft without injuring them with the thrust, Pavlik said.

“Now the Navy has our seat in their whole pipeline. It’s the seat in their trainer airplane, and it’s the seat in the F-18,” he added.

Digital Technology

Sometimes general advancements in technology provide motivation to install upgrades into aircraft. Teledyne Electronic Safety Products has developed digital recovery systems for both the Martin-Baker ejection seats and seats developed by Goodrich to replace old analog recovery systems. The Navy uses the company’s Future Advanced Sequencer Technology (FAST), while the Air Force uses its Digital Recovery Sequencer (DRS), said Mike Summer of Teledyne Engineering.

“The black box recorders in these systems are self-contained,” Summer said. “They have no connections to other systems. They are solely there to record the events surrounding the ejection of the seats on which they are mounted. They remain dormant until the handle is pulled to eject and then a thermal battery is fired to power them up.”

The Navy recognized the need for a system like FAST in the process of conducting investigations of accidents and the reasons why pilots eject from their aircraft. Teledyne developed the system with the Navy and Martin-Baker. The company designed the system with an open architecture that allows the integration of future applications to reduce the impact of such applications on the core design of FAST, Summer said. As such, the system uses commercial-off-the-shelf components.

“Its onboard pressure system measures air coming into the seat to determine the altitude and velocity of the ejection,” Summer said. “The system records information such as the air speed and altitude of the ejection as well as the point where the seat hit the ground.”

In addition to the Navy F14D, F/A-18C/D/E/F and T-45A/C, the Joint Strike Fighter also utilizes the FAST system, Summer said.

Meanwhile, Teledyne recently put its DRS systems into production to replace the analog recovery systems in Air Force ejection seats. Goodrich chose the company to supply DRS units to F-22, F-15, F-16, F-117, A-10, B-1B and B-2 aircraft.

“The analog system has been in use since 1976,” Summer said. “It had to be replaced every seven years, while the Digital Recovery Sequencer has a service life of over 20 years.”

Many of the old analog systems, such as Teledyne’s Advanced Concept Ejection Seat (ACES) Recovery Sequencers, activate the seat’s drogue gun, drogue severance cutter, divergence rocket, stapac assembly, main parachute and harness release. They lack the ability to digitally record the sequence of events that occur during the ejection process, however.

Cooling Down

Development and integration challenges are not limited to things that the pilot can see. Many of the electronics systems that run throughout aircraft require care and maintenance, and such systems can pose a challenge for the companies that develop them. Isothermal Systems Research (ISR) has created SprayCool technology to cool down electronics systems that run hot. With SprayCool, ISR wanted to introduce innovation in cooling systems.

“Basically, we got our start about 17 years ago,” said Karsten Olson, ISR manager of marketing and communications. “Our founder figured out that if you spray the equipment with a nonconductive fluid, you can use evaporation to keep them cool.

“Evaporation is one of the most efficient ways of cooling things, and that’s why your body does it,” Olson added. “As electronics have begun to get hotter and hotter, there has been this need for new types of cooling.”

SprayCool keeps systems cool to prevent processor failure and enable thermal cycling, Olson said. SprayCool systems spray a fluid onto the hotspots of electronics. The fluid immediately evaporates, taking the heat of the electronics away with it, much like the human body does when it sweats. The system cycles the heat out of the aircraft.

ISR designed the system with enough “thermal headroom” to be powerful enough to cool the next generation of technology, which keeps running hotter and hotter as upgrades are developed, Olson said.

The Expeditionary Fighting Vehicle, the amphibious tank in use by the Marine Corps, was the first military vehicle to employ SprayCool, but it expanded to use in the EA-6B. Recently, SprayCool has been introduced into the U-2 and the GlobalHawk aircraft, Olson said.

“Heat was a major issue for many of these programs, but we also come along with a lot of other benefits,” Olson said. “Because we are so much more efficient, we can make the cooling system denser and replace size and weight. A lot of people automatically think that if you are using a liquid to cool something, then it is going to be heavier. On a system level approach, we can densify the electronics and reduce size and combine groups of electronics into one single area.”

In addition, the U-2 program office worried about “cold snap.” The cold air at very high altitudes keeps electronics very cold as well. When pilots power up some systems, the cold snap could damage them. SprayCool is able to solve that problem by warming up the systems first.

“We heat up our fluid and spray it on the electronics and warm them up. Then once they get running and get hot, we turn off the heaters and start cooling. So we can heat as well as cool,” Olson said.

Inspiration for Integration

Sometimes the idea for a new subsystem in an aircraft can come from a ground vehicle, even a commercial automobile, as with an example provided by Joe Shane, vice president of business development for aerospace systems at Armor Holdings.

About a decade ago, the Army released a request for proposals to discover if air bag technology used in automobiles could be applied to helicopters to provide protection for the crew. The Army had examined the cause of helicopter injuries throughout the 1980s and concluded that air bags might help in helicopter crashes.

“So we took a look at the existing air bag technologies and decided that they have the capability of being applied to the military helicopter crash scenario,” Shane said. “In other words, with the timing of the crashes, the air bags can be made to operate within a period where they would provide some protection, but we would obviously have to modify the technology and the systems somewhat to meet the military specifications and requirements for aircraft.”

Armor Holdings developed a program to examine the components of the basic air bag system, which includes a sensor that detects a crash, a mechanism to inflate the air bag with gas, and the bag itself. Armor Holdings evaluated the possibility of adapting those components to a helicopter and developed additional capabilities that would make the system work.

“For example, with your crash sensor in your car, if you hit something, there are crumple zones in the car, and it looks at how fast the car is slowing down,” Shane explained. “We do similar things in the helicopter, but we also have to consider that there are a lot of electronic systems on helicopters that the electronics we are adding cannot interfere with. You don’t want to send signals outside of the helicopter that someone else might detect, and you want to be able to withstand things like lightning strike and other things that you typically wouldn’t see as a problem in an automobile system.”

Helicopters also tend to drop out of the sky as they crash, Shane noted. That prompted the Army to study how the seats and subsystems of a helicopter could protect its occupants at a 50G peak acceleration level and a velocity change of 50 feet per second.

So the air bag was developed to compensate for a seat that would adjust downward to the floor to protect the spines of the crew in a helicopter crash.

“In addition to having all sorts of motion based on the crash forces and the guy bouncing around the interior of the cockpit, you have the additional fact that the seat may move down 10 to 15 inches during the crash,” Shane said. “So you can see there is a fairly large envelope that a person’s head could go into during that time.”

Armor Holdings solved the problem by simulating the factors involved, producing a solution, and fielding the air bags into helicopters, where they help protect the flight crew today.

Integrating Armor

Despite all of the systems that go into making a cockpit work and be comfortable, the cockpit is ultimately defined by the amount of space it occupies. Armor walls that shape the cockpit at the nose of the aircraft define that space. So while military programs can work within the confines of those walls to test electronics or seats or other subsystems, there is still the question of how to introduce improvements to cockpit armor.

Testing new armor for aircraft involves a combination of modeling and simulation as well as fielding the armor on prototypes, Shane said.

“We do computer models and add armor into structures and conduct the stress analysis on them to make sure they could still withstand the structure loads with the armor incorporated into it,” Shane said. “Then we would take the step of doing small pieces to demonstrate that those pieces did perform both structurally and ballistically the way we expected to before we then actually put it into a helicopter for a trial test.”

Armor Holdings has to consider the makeup of the equipment in the helicopter when adding new armor to it, Shane added. The rotor blades of the aircraft and the electronics throughout it generate vibrations. The military must carefully consider those vibrations when introducing new materials to a helicopter to avoid damage , he said.

“There are controlling and dampening mechanisms that many of the newer helicopters have incorporated into them, but you would still want to be concerned about changing the stiffness of the structure and introducing different vibration modes that didn’t exist previously,” Shane said.

Aircraft use a lot of ceramic composite armor systems to reduce weight, rather than the metallic armor found in ground vehicles. A hard piece of ceramic, such as silicon carbide or boron carbide, will be placed in front of a high-strength fabric like Kevlar in an aircraft, Shane said.

“The ceramic stops a bullet and breaks it up into pieces, and then the fabric behind that acts like a catcher’s mitt and catches the broken up materials,” he explained.

Technological advances occur regularly in aircraft armor, making upgrades desirable whenever possible. Within the past five years, Armor Holdings found a significant breakthrough in its ability to shape the ceramic materials into curves, whereas previously the armor had to be flat.

“That gives you the opportunity to, in some cases, contour the armor so that it is closer to the occupant,” Shane said. “You want to put the armor as close as you can to the occupant, because then you have less area that you have to cover. The further you get away from the occupant, the more coverage you need to have, the more square footage of armor to provide the same protection. So if you can put it right next to him, that’s the most efficient way to provide protection from a certain direction.”

Rounded armor surfaces also enable the military to put armor in doors and curved walls that it could not previously protect with armor, Shane added.