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Friday, October 1, 2004

In Search of a Good Neighbor

EMS operators and hospitals take a proactive approach to community noise

John Croft

Two years ago, Sean Flanagan, director of government relations for the St. Joseph Medical Center in Towson, Md., found himself in a bind: Officials at nearby Towson University wanted their sports field back. As the hospital's point man for external relations, Flanagan had to find somewhere else for the emergency medical services (EMS) helicopters that transport cardiac patients to and from St. Joe's to land. The sports field had been an interim, non-optimal solution after the hospital's growth encroached on the existing 1965-era, ground-level landing pad. "It was not our ideal standard of care," said Flanagan. The drive from the intramural fields to the hospital added 10 to 15 minutes to the patient's medical intervention, reducing the chance for survival.

For the university, the landing site had become untenable because the number of arrivals--and disruptions to sporting events--had increased from one or two a month to a dozen after Pittsburgh-based EMS operator STAT MedEvac began serving the area in March 2001 and doctors across the region began realizing that helicopters were no longer limited to air ambulance duties for accident scenes. As St. Joe's was the preferred cardiac treatment center in the state, the number of heart trauma transfers using helicopters belonging to Stat MedEvac or DC MedStar, the area's other provider, accelerated. By winter of 2002, Towson State officials called for an immediate halt to the flights, and St. Joe's opted for a $700,000 helistop on the seventh floor of the hospital.

Expense aside, the critical issue toward gaining approval for the new pad was whether the neighbors across the street would be willing to accept a small but noticeably different dose of noise at virtually any hour of the day. It is a question that is becoming more and more pertinent as air ambulances become a "standard of care" in contemporary medicine. As the standard rises, so do the number of air ambulance trips from rural areas as well as the number of inter-hospital transfers. "The other piece of this is that we're going in and out of hospitals rather than fixed-wing aviation facilities," said Tom Judge, executive director of Lifeflight Maine and president of the Association of Air Medical Services (AAMS). "The hospitals have very wealthy neighborhoods across the street since doctors have a requirement to get to the hospitals often." Judge said that even though in Maine more than 99 percent of the emergency patients arrive at the hospital via an ambulance with a siren, it is the few that arrive by helicopter that get the attention of neighbors. "People are willing to accept train, police car and ambulance noise," Judge said. "But they get concerned about helicopter noise."

This inequality is a fact of life for air ambulances and hospitals, and one that has operators taking a proactive approach in mitigating the disturbances with solutions that range from piloting techniques to operating procedures to physical barriers and technology.

In San Francisco, it has largely been noise concerns that have prevented officials from building a downtown rooftop helipad at the San Francisco General Hospital for nearly two decades. The most recent attempt, launched two years ago, is in the environmental impact report phase, the state equivalent of a federal environmental impact statement. Ricarda Bennett, an attorney and psychoacoustic expert with a specialty in helicopter entitlements, helped prepare a feasibility study that found there would be an "incremental noise increase" in day-night average sound level (DNL) in the helipad area with the proposed one to three daily operations. The study assumed preferred arrival and departure routes with a 10- to 16-deg. slope.

The analysis considered typical background noise levels near the hospital--primarily from Highway 101 and major streets--plus a composite helicopter noise model made up of the four helicopter types (AgustaWestland A109A, Eurocopter BO105, Bell Helicopter 222A, and Eurocopter BK117) using the pad for two daytime and one late-night arrival per day. The analysis did not consider improvements that can be made with piloting techniques. Bennett said by using methods described in the HAI's "Fly Neighborly" program, a pilot can cut noise as much as 6 dB for a landing or takeoff. Among the Fly Neighborly mitigations are beginning a descent before reducing airspeed, using steeper approach/departure angles or making turns in the direction of the tail rotor.

Noise levels alone, however, are not an accurate barometer of a human's response to a helicopter. Bennett said that while everyday background noise levels can reach 60 to 70 dBA, a helicopter, like a lawnmower or jackhammer, has a noise signature that is different, and therefore more noticeable, even though it may top out at 55 dBA. It doesn't help either that helicopters are often depicted in reckless chase scenes on television and in the movies, Bennett said. "That gets translated," she said.

Even in Maine, where the rural character of the land makes helicopters the only option for quick access to specialized emergency health care, noise is an issue. "When I work with neighbors, I don't pretend that a hospital helipad has no effect," said Lifeflight's Judge. The state is in the process of building 17 new hospital helipads over the next 18 months as part of a bond issue that voters approved in 2003. This will bring the total number of helipads to 37. In working with neighbors at a new site, the goal is to chart agreed-upon paths into and out of the helipad after taking into account safety and FAA requirements, Judge said. Preferable paths are over commercial corridors and roads, he said. When wind or other reasons prevent a pilot from flying that route, the crew has to file an exception report with Judge. Out of 1,000 to 1,200 flights a year into and out of Maine's major hospitals, Judge said two or three percent of the flights will result in an exception report, either due to wind or safety-of-flight conditions. "I will fire a pilot if a pilot can't follow the way we work, the agreed-upon procedures," he said, adding, "I've never had to do that."

Maine is also learning that some mitigation techniques have unintended consequences. At the Eastern Maine Medical Center in Bangor, officials built a semicircular sound wall to protect a neighborhood on one side of a new rooftop helipad. Unfortunately, the wall acted as an amplifier that trumpeted helicopter noise three eighths of a mile in the opposite direction, drawing complaints from neighborhoods that previously hadn't been affected. Lifeflight analyzed the situation and found that the noise could be controlled to some extent with the helicopter's orientation on the pad. Lifeflight flies two Agusta A109s.

Technology could also provide some relief in the future. John Leverton, vice president of infrastructure development for the American Helicopter Society, said Bell, Sikorsky and Eurocopter are investigating precise ways to describe the otherwise generic noise abatement tips called out in the Fly Neighborly program. In one case, Fly Neighborly advises pilots to avoid banks to the right in order to cut down on blade-vortex interaction noise (blade slap). By coming up with a specific range of bank angles for a particular make and model helicopter, manufacturers could increase operational flexibility while reducing noise. At the University of Maryland, research continues into cockpit displays that will integrate horizontal and vertical approach and departure flight routes with the Fly Friendly guidelines, providing pilots with a highway-in-the-sky noise optimized path. Leverton said 80 percent of today's fleet will still be around 20 years from now, emphasizing the need for retrofit rather than forward-fit solutions. As for new designs, Eurocopter is taking the lead with its four-year Friendcopter program designed to reduce internal and external helicopter noise and vibration through noise abatement procedures, engine technology, active cabin structures and active blade control. Friendcopter is funded through the European Union's sixth Framework program.

During the approval phase of St. Joe's helipad, Flanagan and STAT MedEvac's Guy Barber, an emergency medical technician (EMT) and program coordinator, teamed up to hold workshops with the local communities. In addition to a chance to explain the public benefit of air ambulance services, the hospital and EMS operator used the meeting to lay out preferred arrival and departure routes and procedures for reporting when and why those routes could not be followed. During one meeting, STAT MedEvac brought one of its helicopters to the Towson landing site to give the community the chance to touch and feel an air ambulance. STAT has a fleet of 16 helicopters at 14 bases, with a BK117 based at Martin State Airport (east of Towson) to serve the Maryland, Washington, D.C. and Northern Virginia area. The company will eventually phase out its BK117s, opting for the quieter EC145s, said Barber.

With St. Joe's rooftop helipad operational for two years, complaints are infrequent but do happen--usually late at night when an arrival or departure, for whatever reason, cannot follow the agreed-upon paths. When that happens, Flanagan is the first person to know about it. Community leaders have his cell phone number and don't hesitate to call at 4 a.m. if a helicopter flies over. "You told us they weren't going to come in over our neighborhood," is usually the complaint, he said. To make sure its pilots are familiar with noise mitigation procedures, STAT MedEvac's operation center in Pittsburgh, which handles dispatching and flight following, provides landing zone (LZ) reports to pilots. For St. Joe's the LZ report includes the preferred approach (from the northeast) and departure route (to the northwest), in addition to information about obstacles and a description of the pad.

While St. Joe's preferred approach path is safe, it is not ideal. There is a 15-story smokestack just off the inbound leg. An approach from the opposite direction would be ideal in terms of obstacles if it weren't for the neighborhood below. The tradeoff, however, is good value for the hospital and the air ambulance companies in the long run given the "huge sensitivity" to noise within the community, said Flanagan. "We rely on the community to support growth and development at the hospital," he said.

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