|A common pilot error, according to U.S. statistics, is “insufficient power available.” This does not mean helicopters are underpowered. Rather, “the pilot is unaware of the power required in the situation,” an FAA analyst said.|
Recently released numbers show that the global helicopter industry will be far short of its self-assigned, highly ambitious goal of cutting the number of accidents by 80 percent over the 2006-2016 period, if current safety trends continue. Therefore, civil aviation authorities are striving to find new ways to reach out to pilots and operators, as well as manufacturers, to improve a relatively worrying situation. Means include new rules but also easy-to-read leaflets. Meanwhile, manufacturers are introducing new design processes and equipment to do their share of the effort, it appeared at the annual Rotorcraft Symposium the European Aviation Safety Agency (EASA) organized in December in Cologne, Germany.
Bob Sheffield, a member of the International Helicopter Safety Team (IHST) and AgustaWestland’s senior advisor for safety and fleet operational improvement, said that some regions are going the wrong way in terms of helicopter accident statistics. The global trend is a slightly declining number of accidents per 100,000 flight hours. At 5.7, it is still too high to leave room for reaching the target of 1.9 (accidents per 100,000 hours) in 2016 set by the IHST. These numbers are badly influenced by three regions—South America, Asia and Oceania. There, the trends are upward.
Those regions where the accident trends are downward are Europe, North America (but both are still short of the reduction goal) and Africa. So was the 80 percent goal over-ambitious? “It was rather a federating aspiration, coinciding with the creation of the IHST,” Michel Masson, EASA safety action coordinator, secretary of the European Helicopter Safety Team (EHEST) and co-chair of the European Helicopter Safety Analysis Team (EHSAT), told Rotor & Wing. He insisted the effort is likely to be carried on after 2016, especially if the goal is not attained.
The EHSAT and the European Helicopter Safety Implementation Team (EHSIT) are part of the EHEST, itself the European chapter of the IHST. The causes of these not-so-good safety trends are hard to find. “Is the economic downturn an explanation for the hiccup we see on the graph from 2008?” asked John Steel, a representative of the Irish Aviation Authority and co-chair of the EHSIT. His team is still analyzing this possibility. Another possible explanation is a discrepancy between training and technology—a Robinson R66 is equipped with a glass cockpit and a Fadec, Steel underscored.
“Helicopters are safe but some are not operated as safely as they could be; and we know how to make flying on a helicopter much safer,” Sheffield stated. Some passengers may disagree with the first part of the statement. “Over the 1992-2009 period, 31 percent of offshore accident causes were technical,” according to Olivier Claeys, head of aviation at Total. The oil company simply wants helicopter transport to be as safe as airlines.
Not all types of operations appear the same way in safety statistics. For example, in the U.S., private, training and crop-dusting flights are the top three numbers of accidents. Several speakers, however, noted that collecting data is challenging. It has been impossible, for instance, for the EHEST to correlate crashes to numbers of landings.
Dave Howson, a research project manager at the UK civil aviation administration (UK CAA), pointed at a cruel lack of contextual information. He was referring to annual flying hours by type of operation and aircraft type, flight time distribution by flight phase, as well as pilot flying experience and age. “If we had started collecting when the EHEST was launched in 2006, we would have five-plus years of good data by now!” he complained. Most accidents involve Part 27 (lighter) helicopters, Howson noted. Yet, Part 29 (heavier) helicopters are included in the statistics. “Do they cloud the picture?” Howson asked. Not a lot, it appears from his work. He studied Part 27-only accidents over the 2000-2010 period. The same two causes keep the top spots—pilot judgment and action, and safety management. The main difference is maintenance—as a cause, it appears five ranks higher in the Part 27 focus.
Looking for a clear picture of causes, too, Lee Roskop, an operations research analyst with the U.S. FAA, studied 2001-2010 U.S. data. He noted that loss of control took the top spot in the “occurrence categories.” The most common error was “insufficient power available.” Roskop clarified that this does not mean helicopters are underpowered. Rather, “the pilot is unaware of the power required in the situation,” he said.
Also from U.S. data, some misperceptions emerged. Personal and private flights have seven times worse statistics than helicopter emergency medical services (HEMS), which have been highly scrutinized over recent years. Moreover, common perception that most U.S. helicopter accidents occur either at night or in bad weather is not supported by data. A very high proportion (95 percent) of them occur in visual meteorological conditions (VMC).
To help curb accidents, the IHST now has a revised strategy, Sheffield said. At stake is reaching “those who haven’t heard or heeded the IHST’s recommendations.” IHST thus wants to leverage contacts with license holders—regulators, insurers, manufacturers and “best” operators. EHSIT’s Steel identified general aviation as a major target.
Moreover, the IHST wants to focus on the training sector. “It is currently the highest source of accidents,” Sheffield insisted. He sees an opportunity to create a “safety mindset in new pilots.”
He emphasized the cultural aspect. “The stories you tell can overtime change the culture so let’s spread success stories,” he said. Steel put it almost the same way: “Monkey see, monkey do.” He also urged operators to give more feedback to the authorities.
EHSIT has released a number of safety promotion materials and tools for the operators, especially small ones. The safety management system (SMS) toolkit, released in July, consists of a safety management manual, an emergency response plan and a safety management database user guide. “It is ready to use and it is the first product that was built around the recently published European rules,” Masson said. It is targeted at “complex” operators—a category that depends on criteria like the type of operations (hoist, HEMS etc.) and the environment (mountain, offshore etc.). “For non-complex operators, we’ll issue a lighter toolkit in 2013,” Masson added. Another tool is a pre-departure risk assessment checklist. Its purpose is “to make pilots and technicians aware that small simple situations, when combined, can raise the total risk significantly.” The pilot first scores the initial pre-flight situation. If an item is scored “red,” mitigating action must be taken.
EHSIT has published the top training-related recommendations in leaflets. “We have released videos on degraded visual conditions, loss of control and passenger management—seen from the pilot and seen from the passenger,” added Gilles Bruniaux, EHEST co-chair and a Eurocopter’s vice president of fleet safety. Some documents have been translated into other languages than English, Spanish and Italian, for instance. “We want to reach everybody,” Bruniaux said. All these tools are provided free of charge.
What about improving aircraft certification processes? This is what EASA is endeavoring to do with its “level of involvement” project. As the agency’s deputy certification director, Frédéric Copigneaux, highlighted, the role of the EASA is to check the validity of demonstrations by the applicant. “We don’t check 100 percent but the present rule does not say how much,” he said. So the project is about defining the principles to be used to determine the agency’s level of involvement. EASA will take into account the novelty (for the manufacturer and/or the agency) of the domain. It will also factor in its criticality. A manufacturer is already rated as a design organization and its performance level will be heeded, too.
For example, let’s take a top-level design organization that is submitting a demonstration for a non-critical item it has experience with. The EASA will not verify the demonstration. If the domain is novel and critical, a verification will take place. Should the item be rejected, the manufacturer may be downgraded as a lower-performance design organization. In turn, this will increase EASA’s level of involvement the next time the manufacturer applies for certification.
Copigneaux is trying to gather industry support for the “level of involvement” project. Depending on the response, it could take the fast track through rulemaking, he said. He made it clear it is not only about rotorcraft.
Meanwhile, the Swedish transport agency is to issue a regulation for some operations that were simply not regulated—SAR. “We had several accidents over the last 10 years, we heard requests from the Swedish pilots association and we listened to our investigation board’s recommendations,” project manager Annika Wallengren said. Search and rescue is outside the EASA’s remit so it is up to the nations to regulate. Spain is to publish a regulation in April.
SAR is a risky business, as Wallengren put it. Low altitude, hostile environment, bad weather and demanding maneuvers are often combined risk factors. “We want to create a tool to assist crews in not stretching a flight,” Wallengren said. The project is at the draft stage. There are a lot of stakeholders—the country’s maritime organization, police, coast guard, armed forces and HEMS, as well as neighboring countries, the EASA and operators interested in performing search and rescue. The plan is to have the new regulation entering into force next autumn.
Requirements at the helicopter level may include a flight management system, radar, terrain warning system and night vision equipment. The required navigation performance may be a precision of one nautical mile (RNP1). Operational minima will be set for transition down over the water. There will be requirements at the crew level, too.
Talking about pilots, the International Federation of Airline Pilot Associations (IFALPA) is worried about fatigue. Helicopter committee representative Tony Ridley called for better flight time limitations (FTL).
He insisted pilot fatigue is “a known causal factor in up to 20 percent of all human error-attributed accidents in aviation.” But he blamed EASA for being slow to adopt new FTL rules, which the agency expects to fully implement in 2015. They are all the more important, Ridley said, as a sound FTL basis is needed for “a promising tool”—the fatigue risk management system (FRMS).
An FRMS, established at the operator level, monitors fatigue-related risks. It uses scientific principles and operational experience, Ridley emphasized. IFALPA, ICAO and the International Air Transportation Association (IATA) have co-branded an FRMS guide for operators.
“An FRMS allows flexible, specific and timely responses to constantly changing operational needs—ideal for helicopter operations,” Ridley stated. As helicopter specifics should be taken into account, he mentioned noise, vibration and lack of cockpit cooling or heating. He did not forget the inconvenience of wearing survival equipment.
Helicopter manufacturers believe they can improve safety with new designs. Rotorcraft programs, however, have become highly complex, Eurocopter’s Guillaume Maurel said. He sees a helicopter as a “system of systems,” using new technologies such as integrated modular avionics and high-speed networks. On top of that is the need for faster development cycles.
The Marignane, France-based manufacturer is thus adding one step between system-level testing and the flying prototype. The approach is named “Helicopter Zero.” It will be used for every new Eurocopter design. This is starting with the X4—a codename for an in-development AS365 Dauphin/EC155 replacement.
“The idea is to detect issues early,” Maurel explained. In fact, there will be two “helicopters zero”—the “system” one and the “dynamic” one.
The system helicopter zero is the coupling of an “integration cockpit” and a “vehicle integration rig.” It looks like an extended test rig. It integrates as much real equipment as possible—avionics, vehicle systems, flight controls etc. Electrical generators and hydraulic pumps run thanks to power units that replace the engines. Engineers, test pilots etc. can sit into an almost real cockpit. The system helicopter zero even allows to install flight-test instrumentation.
The dynamic helicopter zero is meant to be fully representative of dynamic system integration. Looking like a real helicopter, it is based on a vehicle platform equipped with real dynamic systems (rotors, transmissions, engines, flight controls, hydraulics, electrical generation etc.).
Once the developed aircraft is in service, a “helicopter zero” (either dynamic or system) can help replay incidents.
Eurocopter also is looking at the way operators use their helicopters to offer specialized equipment. For example, Class C sling load operations mean the load is in contact with the ground (or water). This is the case when a helicopter helps install a power line. To keep piloting reasonably difficult in such a configuration, the sling’s angle with a vertical axis must be limited to 30 degrees. A ballast weight is used.
Eurocopter engineers have designed a system that ensures that the angle stays within the limits. It combines inertial attitude reference and a mechanical system. The combination ensures the required design assurance level (i.e., robustness) is met. Thanks to a graphic display, the pilot can see where (in what quadrant) the load is, and what the sling angle is. An alert can be heard from 25 degrees.
For a given mission, French operator Airtelis has demonstrated that the ballast weight under an EC225 could be reduced from 3 to 2.8 metric tons. Hence an improvement in the fuel load. Airtelis, a specialist in power lines, has used the system since mid-2012. Eurocopter is considering adapting the Class C system to other types than the EC225.
Pilots also need help in degraded visual environments (DVE). Dutch research center NLR has studied three ways to address reduced visual cues. The most accident frequent scenario in such environments is controlled flight into terrain, due to a lack of ground texture. The second one is inadvertent entry into instrument meteorological conditions, researcher Joost Vreeken said. There is a peak of DVE accidents with light rotorcraft so aiding systems should be suited to that category.
The first concept tested is the Malcolm horizon, where a 150-degree field-of-view line appears on the windshield. It is projected from inside the cockpit. It portrays roll and pitch.
The second concept is the head-up display (HUD) orange peel. A semi-circular line appears on the windshield in straight and level flight. Depending on roll and pitch, the line morphs into a more or less complete circle. So the pilot knows where to move the cyclic stick to regain a straight and level attitude.
The third concept is peripheral-vision LEDs. They appear on the three windshield’s uprights—one in the front, two on the sides. They illuminate from the floor to the horizon, from the pilot’s eye reference point. Front-backward lights indicate pitch attitude. Meanwhile, moving red lights depict the sink rate.
The NLR tested the three concepts with six pilots. Three of them were experienced, while the other three were less experienced. None of them had an instrument flight rating. It turned out that the HUD orange peel was the most accepted concept.
It was deemed the “best usable cue environment.” However, it is prone to pilot-induced oscillations, Vreeken warned. Moreover, it tends to attract focal attention away from an outside scan.
Also aiming at improving safety in DVE, AgustaWestland is participating into a European research project. Spread over the 2009-2013 period, it is dubbed Alicia, an acronym for “all-condition operations and innovative cockpit infrastructure.” The EUR40 million ($52 million) effort is not only about helicopters. But it does consider a whole strategy towards safe landing of a rotorcraft in an unprepared area, in DVE.
As a first step, for en-route flight, the navigation and terrain/obstacle database can help define a “safe height boundary.” Landing at surveyed sites, using “cleared corridors,” is envisioned. Equipment would include an obstacle warning system, synthetic vision of terrain (on a head-up or helmet-mounted display) and a terrain avoidance and warning system.
In the next step, the addition of a steerable forward-looking infrared (FLIR) sensor would allow landing at unsurveyed sites. Finally, adjoining a millimeter-wave radar would enable “flexible flight below the safe height boundary. However, “display of imagery should be eyes out and conformal to allow the pilot to use the remaining visual cues,” AgustaWestland’s David Tyler warned.
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