Story ID: 136AMTCAIN0117
HEMS Industry Getting Safer
By: Mark Huber
Caption: The helicopter EMS industry is reducing the number of accidents and fatalities.
Word Count: 1284
Dr. Ira Blumen is the program/medical director for the University of Chicago's Aeromedical Network (UCAN) and for the last 17 years has been one of the nation's foremost researchers on the helicopter EMS industry, administering a nationwide annual survey that gleans an 85-percent response rate. He shared his data mosaic and the trends it suggests during a presentation at last month's Air Medical Transport Conference in Charlotte, North Carolina. Among the recent trends Blumen noted: a lower accident rate holding steady, fewer patient transports, a slight uptick in the number of hours flown, a record number of flight hours for the fleet as an aggregate and—for the first time—a net decline in the number of dedicated operational EMS helicopters in the U.S.

Blumen began collecting data in 2000 at the behest of his then section chief, who wanted to gain a more thorough understanding of how helicopter EMS compared with other types of flying in terms of safety. Aside from an excoriating 1988 NTSB report that chronicled the industry's abysmal safety record in its early days—an overall accident rate twice that of other Part 135 operators and a fatal accident rate 3.5 times as high—precious little data had been collected in the ensuing years. "You can't fix what you can't measure," Blumen noted.

Blumen's initial research, titled "A Safety Review and Risk Assessment in Air Medical Transport," was published in 2002 by the Air Medical Physicians Association (AMPA). "Knowledge comes from experience, and experience comes from poor outcomes. And we have had more than our share of poor outcomes. My program had an accident in 2005, so we found out right then and there that it can happen to you," Blumen said.

While the industry's safety record was downright grim in the 1980s—crewmembers had a 1:100 chance of being killed, Blumen noted—overall the safety record has been improving, save for the accident spike of 2008 in which there were 13 accidents and 29 fatalities. Helicopter EMS crews gained the dubious distinction of temporarily having the most dangerous profession as measured by the National Safety Council. However, the number of annual accidents has declined over the last several years to an average of 8.3, down from an average of 12.75 from 1998 to 2005.

It is important to keep those numbers in historical perspective, Blumen emphasized. From 1972 to 2016 there were 342 helicopter EMS accidents. Of those, 329 involved aircraft dedicated to EMS and 13 involved dual-purpose aircraft; 123 of those 342 resulted in at least one fatality.  Some 1,053 personnel were involved in those accidents; 328 died, 116 sustained serious injuries, 136 had minor injuries and 473 were uninjured. Of the dead, 266 were crew, 13 were dual-purpose crew (such as a sheriff's helicopter transporting a patient); 40 were patients and nine were others such as patient family members or ride-alongs. Looking at this data, this is what jumps out at Blumen. "There were 725 survivors, [meaning] 68.8 percent survived. The survival rate was better than two-to-one."

Looking at the data from the more recent period of 1998 to 2016, there were 222 accidents involving 214 dedicated aircraft and eight dual-purpose ones; 73 had at least one fatality. Among the 669 personnel aboard, there were 187 fatalities, 76 serious injuries, 73 minor injuries and 333 uninjured. Of the 187 dead, 153 were crew, seven were dual-purpose crew, 21 were patients and six fell into the "other" category.

Here's what is significant in all this, Blumen said. "In the early days of  helicopter EMS, 40 percent of accidents resulted in at least one fatality. From 1990-1997 that number rose to 46 percent. From 1998 to 2016 it declined to 32 percent, while the number of uninjured rose to 51 percent. We're doing something right. More people are surviving with no injuries. And we are seeing a much lower percentage of fatalities."

But it's different in the dark. While the split between daylight and night accidents is almost equal—night accounts for 49 percent—nighttime accidents are far more lethal, with 67 percent resulting in fatalities, even after the widespread adoption of night-vision goggles. Between 1998 and 2016 HEMS operators flew 5.2 million flight hours; 36 percent of those were at night. Forty-two percent of accidents occur on patient missions involving on-scene responses. Human factors played a role in 94 percent of all accidents, followed by weather (25 percent), mechanical (24 percent), controlled flight into terrain (21 percent) and landing zone mishaps (9 percent). Blumen noted that while weather is less of a factor in accidents now than it was 15 years ago, when weather is added to the brew it is lethal: two-thirds of weather-related accidents end in fatalities.

The type of equipment flown appears to matter. In the period between 1998 and 2016 an almost equal number of singles and twins (116 versus 105) were involved in HEMS accidents, but the rate of accidents for single-engine helicopters is climbing disproportionate to their percentage of the HEMS fleet. Singles accounted for 35 percent of the Part 135 HEMS fleet in 2003; today those helicopters account for 53 percent. Since 2009, singles have had a clear and disproportionate share of the accidents; this year they will account for 75 percent of all HEMS accidents. This is significantly above the trend from 1998 to 2016, when singles composed 45 percent of the fleet and accounted for 59 percent of all HEMS accidents.
Flight Hours and Transport Missions
Blumen noted some other interesting trends. First, the number of helicopters has grown, while the number of flight hours each individual helicopter flies has shrunk, as has their number of individual patient transports. However, flight hours per ship and patient transports appear to be gradually creeping up over the last year. But the historical data shows that the average aircraft flew 800 hours in 1994 and 600 hours between 2003 and 2008, at which time flying dropped precipitously after the accidents of 2008 and the ensuing negative publicity.

"People said, 'We are not sending our patients in helicopters,'" Blumen noted. Now the number of flight hours per helicopter is moving up again, averaging 490 in 2016. Flight hours are up 25 percent, but the number of patients is down by 22 percent. Blumen attributes this in part to the continuing consolidation of rural health-care resources. While there are fewer patients, often they need to be flown greater distances. The average U.S. EMS helicopter transports 350 patients per year, and EMS helicopters fly 300,000 patients annually. Since 1980, operators have flown 6.37 million patients. Aggregate fleet flight hours exceeded a record 400,000 for the second year in a row after hovering in the 300,000 to 350,000 range for years.

Unfettered competition has allowed the nation's HEMS fleet to mushroom from 151 aircraft in 1986 to 309 in 1996 to 648 in 2006 to 852 today. If you add in dual-purpose aircraft, the number is 979, and it could be as high as 1,048 if you count non-operational spares. But one thing is certain, "This is the first year ever there has been a contraction in the number of helicopters," Blumen said. Consolidation in the number of HEMS programs nationwide is continuing, perhaps a sign that the industry has reached full maturity. In 2002 there were 231 programs operating 377 aircraft; today 218 programs operate the current fleet.

Without a doubt HEMS is safer now than it was in its early years. In 2002 it had five accidents per 100,000 flight hours; today the rate is 2 to 2.5 per 100,000 hours. Over the course of the last 37 years, 5.5 percent of the programs and 3.5 percent of the helicopters could be expected to have an accident every year; over the last 19 years those numbers dropped to 4.7 percent and 2 percent, respectively. In 1980, a HEMS crewmember had a 1 in 50 chance of being in a fatal accident; today that number is 1:850. Blumen has one final compelling statistic.

"Carelessness and complacency accounted for 40 percent," of HEMS accidents. "More than weather, more than CFIT. Absolutely assume nothing. Accountability, not just safety and rulemaking; that's got to be the secret weapon. If you think an accident can't happen to you, you're wrong."