PETERSON AIR FORCE BASE, Colo. -- Descending above the runway and coming into the wind, the wings are aligned. It’s a beautiful day for a flight and vision is clear for hundreds of miles. In the midst of this peaceful scene a shadow suddenly darkens the daylight; a loud, high-pitched screech encompasses the senses. Finally a thud and breaking glass mark a collision between bird and a jet airplane.
During 2016, the Air Force Safety Center reported about 4,000 such incidents, some resulting in human injury, at a cost of roughly $21 million. These violent encounters between wildlife and aircraft are a serious issue around airports. The Bird/Wildlife Aircraft Strike Hazard team exists to address the issue and take necessary measures to prevent them from occurring.
“The program, in a nutshell, is the mitigation of wildlife hazards on, and around airports to reduce the risk of wildlife strikes,” said Darron Haughn, 21st Space Wing aviation safety manager.
Mitigation involves consideration of various factors. Haughn mentioned standing water, ponds, roosting areas, food sources and migratory pathways as a few of the items a BASH plan considers.
Within the realm of the 21st SW, many of these factors are present at Thule Air Base, Greenland. Haughn and Doug Ekberg, wildlife biologist with the 21st Space Wing safety office and the U. S. Department of Agriculture, visited Thule AB Aug. 10-18, 2017 to determine the steps for successful BASH mitigation.
“They have never had (a bird/wildlife airstrike incident),” said Haughn. “But just because they haven’t, doesn’t mean they won’t. They don’t have a problem now, so we are being proactive.”
Populations of some birds have increased at Thule AB, making the likelihood of striking an aircraft higher. For example, the Canada Goose population increased in recent years, as have Snow Geese and Glaucous Gull numbers.
“That’s why we brought Doug out here,” Haughn said. “We need to see what we might need to do to increase mitigation.”
A Canada Goose strike might not happen often, but when they do Air Force Safety Center statistics show they are costly. Between 1995 – 2016, Canada Geese were responsible for $94 million in damage, including injuries. The team must remain cognizant of size and potential for damage of each type of animal, Haughn said.
Small birds and even other types of wildlife are hazards when they are around a flight line. Arctic foxes and hares on a runway are recipes for disaster, Ekberg said. Even the local polar bears could lead to a disaster if they get onto the runways.
“We are trying to plan for the next five years to make sure adequate BASH mitigation is in place,” said Haughn. “Even though there is a low risk now, it could be a whole lot higher.”
“Complacency is where you get into trouble,” added Ekberg.
In particular, Ekberg said water is an ongoing issue at Thule AB. Birds make nests in those areas, and frequent them often. When they take off to find food or to migrate they are right in the danger zone for a strike.
“Pooling water creates great habitat for geese,” said Ekberg. “They are nesting next to these pools and feeding in the surrounding areas.”
Traveling from what Ekberg calls “loafing areas” to food sources is one of the most hazardous behaviors birds undertake and it can be different for every species. Some of the typical bird behaviors can make mitigation challenging at any location, not just Thule AB.
“Ravens fly from their roost site to a landfill,” he said. “Canada Geese fly from a lake to a golf course. Gulls will fly from a roost to a taxiway or runway to feed on worms that are coming out after a rain shower. Mourning doves fly to sunflower patches to feed. American Kestrels will (hover) for mice.”
Natural features around Thule AB contribute to creating conditions not favorable to mitigating aircraft vs. wildlife collisions. Large bodies of water surrounding the area, boulders and even existing signage present unique concerns, Ekberg said.
“If a plane tries to avoid an animal and goes even a little bit off the prepared runway it is going to mean damage,” he said.
Attempting to keep Thule AB’s perfect record of no bird/wildlife airstrikes intact, Haughn and Ekberg are taking steps to stay ahead of potential problems.
“We are having them take weekly wildlife surveys over the next year to see what kind of trends there are,” said Haughn.
A specific BASH protocol is being prepared and will be given to the Thule AB safety officials. They also are working with local authorities to improve mitigation practices, Ekberg said.
Some helpful actions are as simple as steepening waterfront banks preventing ducks and geese from nesting, Haughn explained. Other measures, such as using “bird balls” – small balls that cover the water’s surface – to keep geese from landing, or aerial cable grids are being investigated as well.
“It comes down to cost benefit risk analysis,” Haughn said. “We are working with vendors to see if these tools are viable.”
Whether it is large wildlife like geese, vultures and polar bears, or smaller creatures like foxes and mourning doves, the BASH team from the 21st SW continues to proactively approach preventing catastrophic collisions with aircraft.