Thick Skin
by Peter Baddeley, SOTECH Correspondent
“Typically, a government customer will contact us and tell us that they bought an aircraft or a helicopter that they originally did not intend to provide with armor but that they need armor now.”
That’s how Mike McCormack, vice president, Foster- Miller Inc., described how they receive orders for add-on armor for aircraft. “We will usually come in and look at the flight deck,” McCormack continued. “The customer then proposes a list of threats they want to defeat, and we work on an armor design to incorporate those issues.”
The armor developed in this fashion is packaged in a kit that is shipped off to be installed by warfighters in the field. “We provide assembly instructions so that military personnel can install it themselves,” McCormack said. “We take great pains to document everything and make it soldier friendly.”
All of the U.S. military services, as well as others around the world, are increasingly seeking to exploit advances in materials development to protect personnel and airborne assets. The key, in the case of fixedwing aircraft and helicopters, of course is to maximize ballistic protection with the lightest possible materials, so as not to compromise the airworthiness or the payload capacity of the aircraft.
The Protective Group (TPG), Miami Lakes, Fla., received an even more urgent call than usual in 2001. On September 10, 2001, The Protective Group had been awarded a contract to provide its ballistic protection system (BPS) to the 160th Special Operations Aviation Regiment (Airborne), Fort Campbell, Ky.
“Based on events that transpired the day after contract award,” related Colonel Newman Shufflebarger, the Army’s acting deputy program executive officer for aviation, based at Redstone Arsenal, Ala., “TPG was tasked with accelerating production and delivery of the BPS system. On November 1, 2001, the first BPS kits were received and were installed on MH-47s in Operation Enduring Freedom.”
Since then, the original BPS has been adapted to meet a variety of Army platforms, including the gamut of Army MH-60 Black Hawk and MH-47 Chinook variations, as well as for Marine Corps (CH-53D/E, MH-53E, MH-60S air ambulance/AHWS) and Air Force (search and rescue HH-60G) platforms. TPG has also since modified BPS to accommodate the command control (UH-60A2C2S), medevac (HH-60L) and the latest utility (the UH-60M), and cargo (the CH-47F) helicopters.
The BPS originally designed the MH-47s “to meet the contemporary Middle Eastern threat spectrum,” said Shufflebarger. “The system was user maintainable, versus depot maintainable. Installation on an MH-47 took less than 30 minutes and required no additional tools.”
Foster-Miller first got involved in the add-on armor business by developing a mechanism, patented in the United States and internationally, for attaching the armor to the aircraft. “What we saw in the 1980s was that DARPA [the Defense Advanced Research Projects Agency] was giving more funding to armor research projects than to attachment systems,” said McCormack.
The company developed its first armor recipe in time to outfit AFSOC C-130s for the Bosnian campaign in the late 1990s. Since then, Foster-Miller has developed armors for other U.S. aircraft as well as for the aircraft of 16 militaries around the world, including those of Spain and Italy.
The development of armor for specific projects involves a trade-off in weight, cost and performance, depending on the customer, said McCormack. “The U.S. Air Force has standardized armor that has obtained the optimal mix,” he added. “But some customers go for ultra-lightweight armor, and some want a less expensive product. It also has to do with the threats they need to defeat.”
Armor recipes, as they are called, generally fall into two categories, according to McCormack: ceramic composites and ultra-lightweight polyethylene. “Ceramics defend better against closer and higher velocity threats,” explained McCormack, “while polyethylene is used to defend against farther distance or lower velocity threats, or fragments.”
Foster-Miller’s patented hook and loop armor attachment system requires no permanent modification to the aircraft affixed with the armor and does not effect flight worthiness, according to McCormack.
The Army’s aircraft ballistic protection program for Black Hawks and Chinooks is managed by the utility and cargo helicopter project offices. “Every aircraft in-theater has this protection,” said Shufflebarger. “Both program managers continue to monitor industry to seek a more capable system to include greater protection and/or a lighter BPS that still retains the necessary reliability and maintainability of the system for the aircraft and the soldier.”
One specific feature the PMs are currently looking for from industry, Shufflebarger noted, is a “ballistic protection capability that can be installed under the floor prior to a unit’s deployment so as to reduce the maintenance burden on the soldier while they are deployed and that can then be quickly removed upon leaving the operational theater.”
The Navy is also looking for newer and lighter weight material for aircraft ballistic protection, and to that end made a series of Small Business Innovative Research (SBIR) awards to a number of different companies, including The Protective Group, in 2005.
Another one of the awardees is American Technical Coatings Inc., a Cleveland-based research and development company, which, like Foster- Miller, came to the aircraft armor business sideways.
“This is the one and only SBIR we ever were involved with,” said company president Charles Inglefield. “Most of our business comes from funding from companies like Raytheon, Northrop Grumman and General Electric to develop pieces and parts for missiles and jet engines.”
Having developed what Inglefield describes as a plastic-like material for these components, ATC came to develop armor by happenstance, after a discussion with a government representative at a trade show got Inglefield thinking that his product, dubbed Hotblox, could provide ballistic protection.
“Ceramics have to be cured at super-high temperatures,” Inglefield explained. “Ours just takes a couple of hundred degrees. Ceramics take a four-step process to mold in a foundry. Hotblox powder gets heated to 250 degrees and turns into a gel that is ready to be molded.”
To fashion armor out of Hotblox, ATC built several layers of the material over an energy-absorbing cloth such as Kevlar to create a concoction that Inglefield calls “lasagna.” The Hotblox armor places the densest material on the outside, with thinner and thinner layers underneath.
ATC’s lasagna has been proved to withstand very high temperatures. In one experiment, it was subjected to 5,000-degree heat from an acetylene torch. “It didn’t even glow red,” said Inglefield. “Meanwhile, the steel plate underneath it started to melt.”
The lasagna has also stood up well to tests of ballistic protection, while ATC also strives to make the material lighter. “The goal of phase one of the SBIR was to be able to stop a standard NATO round and to get the weight down to five pounds per square foot,” said Inglefield. “The Navy wanted us to reduce the weight over the incumbent armor by a full 50 percent.”
ATC hit those goals, so the Navy moved the company on to phase two, where the goal is to get the weight down to three pounds per square foot. At this point in development, the ATC armor weighs 3.4 pounds per square foot.
For the first phase of the SBIR, essentially a proof of concept, the Navy granted ATC $70,000. The second phase, a two-year program with a grant of $300,000, is focused on getting the concept to work in the real world.
“The Navy has also put us in contact with Bell Helicopter, the manufacturer of the V-22 Osprey,” said Inglefield. “Our idea is to take the floor boards out of the helicopter and replace them with Hotblox floorboard.” At this point, this scheme would add some weight to the aircraft.
The next step is phase three, which will be about commercializing the product. “We’re planning to advance to phase three,” said Inglefield. “We keep on making the product lighter, and the Navy keeps on upping the threat level that the armor is supposed to protect against. They keep on moving the goal posts back.”
“We believe we are a couple of months away from being able to commercialize this armor,” Inglefield added. “Phase two ends in 2009, and [we] don’t know when the Navy will give us the green light. Several companies are licking their chops to manufacture this product. I think that within a year or two we will be getting that mystical go-ahead.”
That view comports with how Foster- Miller’s McCormack sees things. “The current state of the art will be available for the next two to three years,” he said. “Most people now working on new armor recipes are looking for the areas of the greatest potential for breakthroughs.”
These areas, in McCormack’s view, include developing transparent armor for bubbles and windows on helicopters and rotary-wing platforms. ♦