Modern planes may be multi-million dollar miracles of engineering able to jet to the other side of the world in a single fuel-up, but their highly technical operations are still vulnerable to the whims of the original masters of the sky: birds.
Each year, the FAA logs more than 10,000 wildlife strikes on planes. The last several decades have seen a jump in the number of strikes, thanks to a combination of an increase in air travel, the continued growth of populations of animals hazardous to planes, and improved procedures for reporting them.
While most bird-plane collisions result in dents or minor damage to the exterior of the plane, encounters with entire flocks or just a single larger bird can severely damage a plane, like in the case of an AirAsia X flight, which lost an engine in 2017 after passengers reported hearing "four or five bangs" before seeing an "orange light" outside. Bird strikes on planes caused several headline-grabbing incidents last month alone: A United flight bound for Denver returned to Fargo, North Dakota after a bird hit the front of the plane. Another flight in Scotland's Shetland Islands struck a bird and returned to the airport, with passengers waiting for a replacement flight through the night until the airport reopened the next morning.
Although plane engines are designed to withstand smaller bird strikes—and even in an emergency, airplanes are able to fly on only one engine—bird strike prevention is a priority for airports around the world, with solutions running the gamut from simple to downright wacky.
One of the most popular methods to scare birds off airport land is firing air cannons when birds are present in an area of aircraft activity, but airports also often alter the nearby landscape to be less bird-friendly, filling in ponds or replacing grass with gravel. Some airports with particularly stubborn birds are forced to get creative: Salt Lake City's airport deploys pigs to eat up gull eggs, and border collies chase away herons and egrets at Southwest Florida International in Fort Myers. France's Lourdes-Tarbes-Pyrénées airport even lights up LED screens with a googly eye graphic to scare off raptors "loitering" in the area. (Planes typically encounter birds below 5,000 feet, either shortly after takeoff or before landing; US Airways Flight 1549, for example, struck a flock of geese four minutes after takeoff—at 2,818 feet—and lost both engines before Capt. Chesley "Sully" Sullenberger and his co-pilot Jeff Skiles landed the plane in the Hudson River.)
Andrew Tull, media relations officer for the Metropolitan Washington Airports Authority, says both Reagan National (DCA) and Dulles International (IAD) airports have a virtual playbook of options for managing birds. The airports fire off pyrotechnics ("think firecrackers you can shoot around 100 feet") and air "bird-of-prey and distress calls that deter nesting birds" via speakers in key locations around the airfields. For larger birds-of-prey like hawks, eagles, and owls, Tull notes that the U.S. Department of Agriculture (USDA) has a team of wildlife experts, "on-site to identify, track, safely trap, and relocate the birds." (Indeed, USDA Wildlife Services statistics reported in 2013, the most recent year with data available, that department biologists assisted with wildlife strike prevention at 850 airports, including both civil and military, in all 50 states.)
For the world's largest and busiest airports, like Amsterdam-Schiphol, Chicago-O'Hare, and Turkey's newly opened Istanbul Airport, bird strike prevention is taken to the max with advanced radar systems. These share live, round-the-clock Doppler readings on the size, location, and movements of flocks of birds within miles of the airport, updates which allow controllers to activate air cannons, time arrivals or departures to avoid large flocks, and dispatch staff to use lethal methods to control the bird situation in an area. Air traffic controllers can monitor these systems, and pilots as well as ground crew also report wildlife to airport operations teams. In 2007 Seattle-Tacoma International Airport, situated in a major bird migratory region, became the first U.S. airport to install such a system, reports the Wall Street Journal.
Bird problems aren't limited to active runways, either; hangars housing planes are also vigilant in preventing birds from perching on, roosting in, and especially pooping on planes, as bird excrement is highly acidic and can erode a plane's exterior. Hangars generally scare off birds by placing realistic owl figurines in the space, but high-tech alternatives, like machines circulating air scented with aromas that repel birds, also exist, and are even in use at airports like Chicago-O'Hare. Who knew that pigeons hated the smell of grapes?