System manufacturers say airlines should fit them, pilots are more cautious, and very few airlines are even considering them because of high fuel prices and their economic repercussions. Yet, despite airline problems, the U.S. Department of Homeland Security (DHS) aggressively is pursuing the development of MANPADS countermeasures for use in commercial aircraft.

So just how necessary are they and how great is the threat? Moreover, if these systems are mandated, who will foot the bill? How effective would they be and who would maintain them? And, while the questions rumble on, what is the risk if such systems aren't fitted?

"The risk depends on three variables: motivation, ability and opportunity. There's no question about the first two: That's been demonstrated. But opportunity depends on available weapons," said Capt. Dennis Dolan, first vice president of the Air Line Pilots Association (ALPA) in the U.S., who chairs the association's Counter MANPADS Task Force. He made the statement at a Safety of Flight conference in Windsor, U.K., in November. According to Dolan, about 20 manufacturers produce 37 different types of MANPAD systems. More importantly, some 1% of the estimated 500,000 to 700,000 MANPADS worldwide - or 5,000 to 7,000 systems - likely are available on the black market. Mainly heat-seeking, they typically have a range of five km, an effective altitude of three km and an ultimate speed of Mach 1.5.

As for the threat, Dolan said there have been 36 confirmed attacks on commercial aircraft since 1978, 25 of which occurred in Africa, mostly against helicopters, business jets or turboprop aircraft. Missiles have hit only seven jet aircraft and six survived, he said. Although 25 MANPAD attacks have occurred in the past five years, all took place in areas of unrest. So while the risk is statistically low, the potential availability of such weapons makes the threat very real. The 36th attack, on a DHL Airbus A310 at Baghdad in November 2003, was notable because, although it brought the aircraft down, the crew and aircraft survived. But in this case, said Dolan, it was only the pilot's skill and training that made this outcome possible. It also proved that the structural integrity of large transport aircraft provided "a very favorable platform to survive major damage."

Incidents like the Aloha Airline's Boeing 737 that lost a portion of its fuselage roof and the United Airlines 747 that had a cargo door blown out, were good illustrations of this, he said. By comparison, MANPADS are unlikely to cause such great structural damage because their warheads are small - typically weighing less than two pounds. However, as the DHL incident proved, they could critically damage systems or engines.

Dolan said there are lessons to be learned. Firstly, the integrity of hydraulic systems need to be protected by fuse-plugs, which could isolate damaged sections and help retain fluid. Secondly, pilots should be trained in special situations where systems and controls are very limited, such as when it is necessary to use engine thrust alone to control the aircraft. To this end, the aircraft's flight management system (FMS) and its full authority digital engine control (FADEC) could be enhanced to assist in extreme situations. Moreover, threats still exist from attacks on the ground, which demand different solutions.

Protection Issues

Jonathan Spaul, systems engineer, Countermeasures Dispensing Systems (CMDS) Thales Group, said fitting commercial aircraft with self-protection systems could impact passengers and ground staff because putting military protection systems on civil aircraft sends out a huge message that civil aircraft are vulnerable to attack. Moreover, because these attacks can only occur around airports - when aircraft are flying low enough to shoot at - concerns would heighten about planes being shot down over populated areas. Such systems should have no effect on air traffic management, he said, but at airports, it would be necessary to have handling procedures for decoys or flares so ground vehicles, such as catering, fuel and baggage trucks, couldn't trigger the systems if they collided with an aircraft during servicing. "Aircraft operators will not need specific training courses to store and handle these devices," said Spaul, "but they will need an element of training to handle the extra workload. Consideration should also be given to how these installations impact contracted aircraft maintenance providers and the training issues which that could involve."

Current self-protection systems that use decoy dispensers, he said, have proven to be low maintenance, so they probably would be "lifed" and replaced as whole units. However, systems that used a mix of technologies might generate more difficult maintenance issues, such as the sale of sensitive technologies to airlines of "non-friendly" countries. Qantas' Group Security Manager, Patrick Gallagher, agreed saying that harmonization issues that go along with these systems need to be carefully considered. "Would it be realistic to create different classes of airlines, such as those with protected aircraft and those without?" he asked.

The DIRCOM Solution

While the questions rumble on, counter-measure manufacturers have moved quickly to develop defensive systems for commercial aircraft - mostly adapted from military systems. These fall into two categories: decoy/flare-dispensing systems, to confuse a missile's heat-seeking sensors, and directional infrared counter measures (DIRCOM). In the U.S., the Department of Homeland Security (DHS) consulted industry to set limitations for system manufacturers: A maximum weight of 1,000 pounds (450 kgs), a maximum aerodynamic drag penalty of 1% and a maximum cost of $1 million per aircraft.

To date, DHS has selected two DIRCOM systems as potential providers of civil aircraft protection - one made by BAE Systems and the other by Northrop Grumman. Phase 2 of their development, involving prototype demonstrations, is scheduled for completion by January 2006, while Phase 3 will involve full operational testing. This will culminate in a recommendation to the U.S. Congress for the most viable MANPADS defense solution. ALPA's Dolan described the DHS decision to discount decoy-dispensing systems as "unfortunate," because security depends on a layer of defenses. Notably, decoy-based systems are not "off the table" in other parts of the world, he said.

In line with the DHS parameters, Northrop Grumman's externally fitted, conformal DIRCOM pod complies with the 1% drag limitation, weighs 500 pounds and sells for $1 million per unit. Its power requirement is 1,800 watts.

Northrop Grumman designed the system to automatically detect a missile launch, determine the threat, then activate a high-intensity infrared countermeasure to track and defeat the missile. Such is its effectiveness that Northrop Grumman's military application is being installed on more than 300 fixed-wing and rotary-wing aircraft operated by the U.S. military and for several allied countries.

While DIRCOM is effective, its technical sophistication and military heritage brings into question where aircraft equipped with it might be allowed to operate. Should government sensitivities arise, its maintenance programs likely would be tailored to ensure it was maintained in a "friendly" country.

In addition, to ensure its constant readiness, systems like this will need regular testing, potentially beyond that offered by built-in test equipment. If so, who will be responsible for testing and troubleshooting (should it prove necessary), and who will stock and fit the required spare parts?

If it's left to the manufacturer, would a DIRCOM failure be a no-go item on the aircraft's minimum equipment list (MEL) or, given the pressures to maintain scheduled operations, should airlines take the risk and fly? If so, who would underwrite that risk?

James Shilling, Northrop Grumman's director of commercial infrared countermeasures, said his system would have a 10-day MEL limitation to enable airlines to keep to their schedules. Moreover, at 7 feet long and 18 inches wide, the pod would fit within aircraft containers. So replacements could be shipped where they were needed within 24 hours. "We would expect to maintain the system," said Shilling. "So the pod would be treated like any line replacement unit. The pods are also fitted with indicators to show they're working correctly, so [they] would only need their warning sensors cleaned."

DIRCOM's downside is cost - up to twice the price of simpler dispensers. But Shilling said the $1 million cost per unit per aircraft included hardware, software, installation and technical manuals, which equates to some 70 cents on the price of each ticket for U.S. airlines.

That said, one major U.S. airline has estimated that, in addition to this figure, a 1% drag penalty imposed by such a system multiplied across its fleets will cost it $45 million in extra fuel per year. (BAE Systems' DIRCOM is installed inside the aircraft to avoid this costly penalty.)

Defensive Dispensers

By contrast, the civilian aircraft missile protection system (CAMPS) offered jointly by Saab Avitronics and Chemring Countermeasures, is priced at $500,000 for a dual dispenser system for a twin-engined aircraft. (Raytheon's dispenser system is reportedly $650,000 per aircraft.) Like DIRCOMs, CAMPS has been developed from the military BOL dispenser family, which uses pyrophoric infrared decoys that generate heat at much lower temperatures than pyrotechnic flares. These are in service on F-14, F-15, F-18, Tornado, Typhoon and JAS39 Gripen aircraft.

Specifically designed to protect large aircraft, CAMPS integrates the latest missile approach warning MAW-300 system providing 360-degree coverage, with fast-reacting BOA electromechanical dispensers fitted with newly developed pyrophoric decoys. This material, developed by the Chemring Group, is non-explosive, non-pyrotechnic and not hazardous on the ground. A weight-on-wheels switch prevents the dispensers from ejecting accidentally on the ground, while the sealed decoys only will open in a slipstream above 100 knots.

Each dispenser typically holds 40 decoys but ejects just a few during each activation, enabling the system to deal with several threats. Decoy "life" is expected to be around one year in-service and two-years in storage. Minimum time before removal of dispensers is estimated at 15,000 to 20,000 flight hours. Any corrective maintenance or replacements normally would be aligned with scheduled aircraft checks. Together, two fully loaded dispensers and the MAW unit weigh 66 pounds (30kgs) and can be hard mounted within the aircraft structure. Only the sensor heads protrude into the airflow, while modular design enables CAMPS to be tailored to suit aircraft size. Installation feasibility studies have included Boeing 737 and 767 aircraft.

According to Sten Sýýderstrýým, senior marketing manager Saab Avitronics, CAMPS is totally autonomous and has an estimated threat detection rate of 99%. The MAW's neural net software, he said, enables it to differentiate between patterns of clutter and a real missile firing. This would be further enhanced when MAW-300s are fitted to an in-service U.S. airliner and to a head-of-state aircraft in Europe to measure background clutter during civil operations. The system should be ready for delivery in mid-2006.

The Way Forward

Whether any airlines commit to fitting MANPADS countermeasure technology to their aircraft likely will depend on funding, politics and future events. In September, the International Air Transport Association (IATA), which represents some 265 airlines, revised its industry loss forecast for 2005 to $7.4 billion.

Regionally, it said European airlines would break even; Asia Pacific carriers would make around $1 billion, while North American carriers could lose up to $8 billion.

Cumulatively, it put airline industry losses for 2001 to 2004 at $36 billion, $32 billion of which was lost in North America. With a total industry turnover in the range of $400 billion per year, IATA said fuel now accounts for almost 25% of industry total costs. Given this picture, asking airlines to find a further $15 billion to $20 billion, if the entire world fleet were equipped with MANPADS countermeasures, seems a very big request. Especially as this technology addresses only one of several threats.

"There's a balance to be struck between security and economic issues," said ALPA's Dolan. "If MANPADS remains a threat to national security, as President Bush maintains, then the cost of these devices should be born by the governments that mandate them. Right now, airlines in the U.S. can't even afford pension plans and salaries. The key to this threat is the 'man' with the MANPADS. It's the terrorist we need to stop, not the missiles," he said. "Governments should focus on improving their intelligence as well as enhancing airport surveillance and security."

Capt. Martin Alder, chairman of the British Air Line Pilots Association (BALPA) Flight Safety Group agreed. "These problems are not of the industry's making, so solutions need to be found by those who created them, not the industry. Proposing some solutions that could change public perceptions of air travel might have a far-reaching impact." The question remains: Do commercial aircraft need self-protection systems? Although the MANPADS threat is real, its statistical likelihood (based on attacks recorded to date) is far less than the current air accident rate, which continues to decline.

In a submission to the Aviation Subcommittee of the U.S. Senate's Commerce, Science and Transportation Committee in November, the Air Transport Association (ATA), which represents the principal U.S. passenger and cargo airlines, said airline travel was safer than ever and that airlines remained committed to improving an already exceptional safety record.

Basil Barimo, ATA vice president, operations and safety, reported that between 2002 and 2004, airlines providing 31 million scheduled commercial services recorded just 34 fatalities among nearly two billion passengers carried. Moreover, in 2004, the National Transportation Safety Board reported only one fatal accident in more than 10 million scheduled departures.

Attributing this record to increased reliance on data-driven analysis to understand and mitigate risks, Barimo said that scheduled air service was incredibly safe and that airlines remain committed to improving an already exceptional safety record.

Barimo also credited the joint FAA-industry Commercial Aviation Safety Team (CAST) for leading the way in improving safety for air travel, noting that the CAST goal of reducing the fatality risk by 80 percent by 2007 was "well in sight."

The point is, if proven conventional methods continue to make the industry safer, will the extra investment in MANPADS countermeasures really be worthwhile?

This article appeared in Overhaul & Maintenance's January 2006 issue.