If there are no butterflies in your stomach ... no sense of concern for safety, it's time to get off the medical helicopter rotation.

"Safety is our number one priority. It supercedes even the care of the patient," said Dr. P.S. Martin, director of pre-hospital medicine at Allegheny General Hospital and medical director of LifeFlight.

Although medical helicopters, the equivalent of emergency rooms flying up to 200 miles per hour, have existed for decades, the industry surged in the 1980s.

Today, countrywide there are about 800 helicopters and 150 planes, according to an industry trade organization.

The LifeFlight program itself was established in 1978.

Throughout the years, the purpose of medical transport has not swayed: Provide advanced life support during rapid transport — a helicopter can slash the hour drive from Butler to Pittsburgh down to about 15 minutes.

But only in recent years has the safety of the saviors come into question.

The Federal Aviation Administration reports the number of Helicopter Emergency Medical Service, HEMS, accidents doubled between the mid-1990s and 2004.

The topic is again in the spotlight because 21 people have been killed so far this year in medical helicopter and plane crashes, according to the National Transportation Safety Board.

"This is very alarming," NTSB member Robert Sumwalt said in an interview with the Associated Press. "The safety board continues to be very concerned about the safety of this industry."

Comparatively, there are 15,000 ambulance crashes a year, resulting in about one fatality a week.

Still, folks like Martin say even one medical helicopter fatality is one too many.

"Our goal is to help save lives, not cost them," Martin said.

Allegheny General has housed one of its five LifeFlight base operations at The Butler County Airport for more than 20 years.

LifeFlight, which operates in a 130-mile radius of Pittsburgh, flies about 2,500 missions a year and has completed more than 30,000 transports.

The team at the Butler site responds to about 550 calls a year, and the airport also houses the program's maintenance facility.

An aviation company manages the flight program. The hospital handles the clinical side, manning the Butler base 24 hours a day by a rotating 14 dedicated medical personnel.

Response calls come in at all hours from different agencies including police, firefighters and hospitals.

The nature of the calls range from unexpected serious traumas — like one man who had molten metal accidentally sprayed into his mouth — to acute heart attacks and strokes.

The calls are almost evenly split between patients who need transport from one hospital to another and "scene" emergencies" such as motor vehicle or farming accidents.

Generally at LifeFlight a crew of two critical care nurses, sometimes accompanied by a physician, and a pilot, respond to the call.

The decision to fly is made separately from medical decisions, and it is based on a number of pre-flight factors including weather, maintenance and crew readiness.

"Anyone can stop the flight at any point," Martin said.

The medical flight crew is not told the exact nature of the call before it decides wether or not to fly because circumstances — say, for example, a newborn who is drowning — might trigger an urgency to go on the flight when the crew otherwise might turn it down for safety reasons.

Landing zones are generally prepared by the first responder, sometimes on highways or in open fields.

Butler County, with its flat terrain, often provides good usable space for landing zones, said James Palafoutas, manager of LifeFlight at Allegheny General Hospital.

But even a spot that seems perfect can create hazards. A freshly cut field, for example, can be dangerous as the helicopter could kick up a lot of cuttings that cause visibility issues, Palafoutas said.In addition to advanced life support equipment, each helicopter is equipped with a number of state-of-the art safety devices including equipment to navigate terrain.Lifeflight helicopters can include safety features like SkyConnect, which automatically follows the helicopter; autopilots, and night vision goggles."And the best pilots in the business," added one of the medical flight nurses, Art Russ of Ohio.Martin said even under the best conditions, the flight's medical personnel must keep an eye on conditions the pilot cannot see such as other helicopters, including those of the state police and news agencies responding to the same incident.For that reason, all area helicopter operators meet three times annually to talk about safety and procedures."Everyone gets together and communicates," Palafoutas said.Martin said even circumstances inside the helicopter can cause safety issues, such as intoxicated, combative or traumatically injured patients who can have unexpected reactions.In those cases, the medical staff must rely on medical solutions, such as sedation, and each other."It's just you and your partner in an intense environment," said Kelly Pflugh, 42, of Butler. Pflugh has been a nurse for 16 years and has spent a decade on a medical helicopter, most years with LifeFlight.Martin said some of the greatest risks to safety on medical helicopter trips are mental: complacency or a desire of the personnel to complete the mission.Medical personnel can often put pressure on themselves to complete the transport and get home, said Martin, who several years ago lost a friend in a medical helicopter crash in Wisconsin.Still, Martin said, "There's no better job as far as I'm concerned. You can anonymously slip into someone's life, make a difference, then slip back out. Often, they don't even know you were there."