When animals collide with aircraft, the consequences can be dire; think pilot Chesley B. "Sully" Sullenberger landing US Airways Flight 1549 in the Hudson River after a skein of geese compromised the plane's engines.
In Flagstaff, too, hawks and other animals can result in thousands of dollars' worth of damage to machinery, not to mention the possibility of human injury.
Thus, not unlike its counterparts around the country, the City of Flagstaff and Flagstaff Airport are required by the Federal Aviation Administration to implement tactics that keep animals, both avian and mammal, off of the airfield and out of the way of planes.
Known as wildlife hazard mitigation, all airports must adhere to a set of standards, including an assessment by a wildlife damage management biologist and a plan to address possible wildlife interference.
LOCAL WILDLIFE, AIR TRAFFIC
"We experience an average of about one to three animal strikes per year," said Barney Helmick, airport director at Flagstaff Airport.
These incidents can be be anything from an animal crossing the airfield to a bird hitting an aircraft during takeoff or landing.
“Some years we get none, but some years we get maybe six or so, so that accounts for that average,” Helmick added.
According to the FAA, there have been a total of 27 wildlife-related incidents at Flagstaff Airport since 2008; none of these have resulted in injuries or fatalities. However, engines and other parts were destroyed in several cases.
"In my nine years we've had one accident that we consider serious and it didn’t threaten any people. It was a larger bird that hit an airplane and they weren’t sure what the situation was, so they stopped quickly. That then did some damage to the brakes," Helmick said.
Per Embry Riddle Aeronautical University's Center for Wildlife and Aviation, 97 percent of wildlife accidents in the United States occur due to birds, 3 percent because of mammals and just below 1 percent are attributed to reptiles.
“In Flagstaff, we see some issues with birds, but they are not as large of a problem as other airports. Often what we worry about are coyotes, bears and porcupines. The deer and elk are deterred by our high fencing," Helmick said.
In fact, four-legged animals can be an unwanted return visitor on the 750 acres that make-up the airport's airfield, such as the porcupines that managed to dig under surrounding fencing.
"In the last five years, the only thing that’s been hit in Flagstaff is a porcupine, sparrows and bluebirds," said Archie Dickey, professor of biology at Embry Riddle.
The porcupine has been the only mammal hit in the time frame, an accident that occurred in May 2016 and involved a Skywest Airlines flight.
According to Dickey, this is in part because Flagstaff is not considered a flyway -- an area where birds migrate north and south.
"The big thing about Flagstaff is if birds move north to south, they do so over the Colorado River -- ducks and geese, essentially waterfowl that are larger and therefore pose a larger risk to planes," Dickey said.
The airfield at Flagstaff Airport is more consistent with grassland habitat, so the most abundant species are finches, sparrows and bluebirds, according to Corina Anderson, a Qualified Airport Wildlife Biologist with SWCA Environmental in Flagstaff.
"In the Flagstaff region, we see an uptick in bird numbers in the summer as many migratory songbird species breed in the area such as black-headed grosbeaks, Bullock’s orioles and swallows," Anderson said.
FOOD, SHELTER, WATER
"When we ask ourselves why wildlife is coming onto the airport or near the airport, it usually comes down to three reasons: food, shelter and water. So you look at those three and you try to reduce those," Dickey said.
Among other things, this means eliminating pools of water, maintaining grasses at certain heights and getting rid of prey such as prairie dogs, which attract a myriad of predators including coyotes, hawks and eagles.
“Essentially, eliminating habitat for animals,” Dickey said.
Anderson, who is also an avian ecologist, has conducted FAA Wildlife Hazard Assessments (WHA) at several airports in the Southwest, including Flagstaff. Common preventative measures include installing fencing that extends underground, eliminating litter and open dumpsters and adding appropriate storm runoff drainage.
All staff members at the airport are also given training -- based on the mitigation plan -- on how to shoo wildlife out of the area. This also translates to twice-daily checks of the airfield to ensure that no wildlife is present.
Several airports use modified fireworks shot from a pistol-like device to scare birds away. However, these are used only after a bird is spotted in the vicinity.
A NEW MITIGATION PLAN
Anderson is one of the primary biologists who conducted the most recent Wildlife Hazard Assessment for Flagstaff.
Flagstaff’s previous wildlife hazard mitigation plan was put into place 10 years ago, and the organization is currently in the middle of completing an update to its tactics under the advisement of SWCA.
"A WHA requires a year’s worth of avian and general wildlife surveys conducted at the airport," Anderson said. "The goal of the surveys is to identify what species of animals are present at the airport and why. Once you determine what is drawing the animals to that particular location, then you focus on how that resource can be mitigated to reduce or eliminate the attraction," Anderson said.
Barney said the new plan is set to be completed in three to six months, at which point it will go to the FAA for approval.
According to a report published by the FAA and the USDA, from the period of 1990 to 2017, the FAA received 193,969 reports of animal strikes in the US and 3,864 strikes by U.S.-registered aircraft in foreign countries.
Since 1975, five large jetliners have had major accidents in which bird strikes played a role, according to Bird Strike Committee USA, a volunteer group working to lessen the frequency and severity of wildlife-related accidents.
"The absolute priority of WHAs is public safety. As an animal lover, however, if we can also keep the critters out of harm’s way, then it makes the job even more rewarding," Anderson wrote.