Print headline: Life Savers for the Future
Onboard emergency equipment for the aviation sector is paradoxical in nature: It has to work, and work reliably, when called upon—but the greatest measure of its success is that it is never used.
“For the aviation sector, safety is the business. Without an effective safety regime, an offshore helicopter operator doesn’t have a business. It is only one accident away from a PR disaster,” says David Stelling, global category manager for aerospace at Survitec Group. The British company designs, manufactures and supplies emergency life rafts and life jackets, working with OEMs including Airbus, Boeing, Leonardo Helicopters and Sikorsky.
Manufacturing inflatable safety and survival equipment is a high-value, global sector: Survitec has 3,000 staff, with annual revenues of £400 million ($509 million) and dedicated design and manufacturing facilities in Dunmurry, Belfast, Northern Ireland. In addition to many commercial airlines, a major part of the company’s business is serving the offshore oil and gas market in the North Sea, where helicopters are extensively used to transport offshore workers to rigs from key industry hubs such as the Scottish city of Aberdeen.
The pace of change in the onboard emergency equipment industry is conservative, says Stelling. “Once you’re on a program, you are on it for 30-40 years. You might have a mid-life upgrade, but the pace of change is limited. Let’s say we are supplying a 10-person life raft for a [specific type of] helicopter—there are not going to be lots of changes once the aircraft is in production.”
Life Rafts and Jackets
Life rafts and life jackets are made via traditional manual techniques at Survitec’s Northern Ireland factory. “There isn’t a high level of mechanization,” explains Stelling. The current material of choice for making life rafts (individual life rafts may accommodate four to 46 passengers) and life jackets is a widely used polyurethane-coated nylon. The polyurethane coating protects the base material from corrosion, weathering, abrasion and other processes that would degrade the material over time. Despite the emphasis on traditional, craft-based techniques, some newer manufacturing methods are also gaining traction at Survitec.
“We are moving to a construction that uses a lot more RF [radio-frequency] welding, whereas previously there was greater use of solvent-based adhesives. It is the same technology that’s used to make a hiking jacket you might buy—the seams are usually RF-welded together,” says Stelling.
The RF welding is faster, and “it saves us money, saves us time, and is more consistent and removes any margin for error,” he adds.
Because RF welding is more accurate, there may ultimately be a reduction in the level of testing needed for each raft. In any event, that testing regime remains critically important to ensuring the product meets rigorous industry standards. “Every life raft and life jacket we manufacture undergoes multiple air-holding tests, so we know the integrity of the raft is correct,” Stelling says.
Despite the slowly evolving nature of the sector, advances occur via the introduction of new textiles and materials such as those that can be RF-welded.
Other technological innovations are likely to center on the deployment mechanism for life rafts. “Every aviation life raft on the market relies on a high-pressure cylinder of stored gas,” explains Stelling. “If you remove that, you take some weight from the aircraft, and also remove a hazardous item.” Survitec is working on a proprietary technology using a chemical reaction to create gas and inflate the raft when it is deployed. “It is in the development phase, but it should ultimately allow the inflation of equipment without having to use high-pressure cylinders,” he notes.
For the offshore market, there is also interest in integrating emergency breathing systems into life jackets to increase the air supply that a passenger in an overturned helicopter has, in order to survive long enough to escape from the aircraft.
Other innovations have involved the ergonomics and comfort of the life jackets that must be worn at all times during transit by offshore oil and gas workers and helicopter crews. Journey times to offshore oil and gas rigs have been increasing, as fields farther away from shore are explored and developed, so wearability is an issue. Because of this, Survitec has redesigned its life jackets to be “more ergonomic and comfortable for long periods,” says Stelling.
Flight recorders are also evolving to meet the latest aviation industry regulations. At flight recorder designer and manufacturer L3, key developments last year included the launch of new 25-hr. cockpit voice and data recorders (CVDR) for air transport commercial aircraft, and a new automatic deployable flight recorder (ADFR) for a range of aircraft, including the Airbus A321LR, A330, A350 and A380. L3’s new deployable Model 7300 ADFR is designed for long-range aircraft with extended flight time over water or remote areas. “This recorder system will add state-of-the-art capability to commercial airliners: the ability to be deployed in the event of significant structural deformation or water submersion,” explains Terry Flaishans, president of Aviation Communication & Surveillance Systems (ACSS), a joint venture between L3 and Thales.
Designed to float, the ADFR contains a crash-protected memory module, which also meets new regulatory requirements for voice recording and will be equipped with an integrated emergency locator transmitter to help rescue teams rapidly locate and recover flight recorders. Meanwhile, the new L3 CVDR is capable of recording more than 25 hr. of voice and flight data on a single recorder, addressing European Aviation Safety Agency and International Civil Aviation Organization requirements to extend the duration of voice recording to that time period. L3 says the recorder is lighter, more compact and features innovations including versatile interfaces compared to current-generation recorders. L3 is partnering with several aircraft manufacturers to make this next-generation fixed recorder available next year.
And it is not just flight recorders that are evolving to improve safety. New software systems for collision avoidance are also being developed, and they will eventually make a difference.
ACSS is closely involved in developing new technologies for the next-generation traffic alert and collision-avoidance system (TCAS)—known internationally as the airborne collision-avoidance system (ACAS)—with the FAA and NASA. The new ACAS system, known as ACAS X, is intended to reduce nuisance alerts and support airspace needs in the future, including collision-avoidance requirements for drones. ACSS is currently helping develop different algorithms for manned aircraft, unmanned aircraft and rotorcraft. The company is also designing automatic dependent surveillance-broadcast equipment (ADS-B Out) equipment that will allow air traffic controllers and other participating aircraft to receive extremely accurate information about an aircraft’s location and flight path, which should mean safer operations in the future. “The recent announcement that American Airlines will equip [its] entire A321 fleet with the ACSS SafeRoute+ architecture demonstrates the growing demand for this technology,” says Flaishans.
Similarly unseen by passengers, but providing a critical safety function in the event of a fire onboard an aircraft, thermal management blankets are single-use items only ever replaced in the event of a fire. They absorb heat and protect passengers, engines, wings and some other critical items such as flight recorders and the auxiliary power unit (APU). Industry-leading microporous insulating materials provided by Morgan Advanced Materials are thus vital to ensure aviation safety, explains Marco Pagni, aerospace product and market manager at the Thermal Ceramics business of Morgan in Elkhart, Indiana. He explains that Morgan’s materials are used to provide thermal protection around the engines, in the tail of the aircraft to prevent the spread of heat around the APU and where the engine attaches to the wing (pylon)—again, to protect against the spread of heat or in the event of fire. “Our materials are the first line of defense from a thermal and fire standpoint,” Pagni says.
The introduction of composite materials in aircraft is presenting challenges in terms of keeping temperatures down so that composites maintain their structural integrity, meaning that thermal management materials also play a key role in protecting newer types of airframes, Pagni explains. In the event of a fire onboard, thermal management materials are designed to contain the conflagration and provide the opportunity for the aircraft to descend and land safely. Special materials have been developed by Morgan to insulate flight recorders, he adds: “They can withstand very high temperatures in the event of a crash or a major thermal event, and it’s our materials that allow them to do that.”
One challenge for the company’s designers is to create new materials with outstanding thermal insulation that are also lightweight, to reduce fuel burn. “There is a balancing act,” says Pagni. “Our R&D efforts are focused on providing excellent thermal properties but also reducing weight.” Technologically, improvements to the efficiency of thermal management blankets are required to cope with increased engine temperatures as well as the introduction of new materials such as composites.
“You are always tiptoeing a fine line between creating a new material that is light but has improved performance,” Pagni concludes.