There are all kinds of stories about the effects of birds striking airplanes in the air. Some of these stories have a veneer of truth about them but most often, they are exaggerated and overblown by a public fascinated by the Hollywood version of birds strikes, the one in which a single, small bird can cause the crash of the biggest of planes.
To counter this misinformation, the Bird Strike Committee USA (of birdstrike.org) has put together the following Top Ten myths about bird strikes.
Myth – Bird strikes cannot cause serious airline accidents.
Fact – Since 1975, five large jet airliners have had major accidents where bird strikes played a significant role. In one case, about three dozen people were killed.
Myth – Bird strikes are rare.
Fact – During the period of 1990-2004, over 56,000 bird strikes to civil aircraft in the United States were reported to the Federal Aviation Administration (FAA). This represents only about 20% of the number of strikes that likely occurred.
Myth – Bird strikes are no more of a problem today than 20 or 30 years ago.
Fact – In North America, bird strike hazards are increasing. Because of outstanding wildlife conservation and environmental programs in North America, populations of many bird species have increased dramatically since the 1970s. Millions of acres have been set aside as wildlife refuges and strong environmental laws such as the Migratory Bird Treaty Act and the Federal Insecticide, Fungicide and Rodenticide Act have protected birds and other wildlife. As a result, species like non-migratory Canada Geese, which frequent urban areas such as golf courses, parks, and airports, have more than quadrupled in number from 1985 to 2004. As another example, the double-crested cormorant population on the Great Lakes has increased over 1,000-fold, from 89 nesting pairs in 1972 to over 115,000 pairs in 2004. These increases have led to an increase in the number of birds in the vicinity of both large and small airports and greater opportunities for birds, especially larger birds, to hit aircraft.
Myth – Large aircraft are built to withstand all bird strikes.
Fact – Large commercial aircraft like passenger jets are certified to be able to continue flying after impacting a 4-lb bird, even if substantial and costly damage occurs and even if one engine has to be shut down. However, 36 species of birds in North America weigh over 4 lbs and most of these large birds travel in flocks. About 30% of reported strikes by birds weighing more than 4 lbs to civil aircraft in USA, 1990-2002, involved multiple birds. Even flocks of small birds (e.g., starlings, blackbirds) and single medium sized birds (e.g., gulls, ducks, hawks) can cause engine failure and substantial damage.
Myth – If a bird flies into an engine during takeoff and the engine quits, the airplane will crash.
Fact – Large commercial jets are designed so that if any 1 engine is unable to continue generating thrust, the airplane will have enough power from the remaining engine or engines to safely complete the flight. However, because many birds travel in flocks, there is always a possibility that birds will be ingested into multiple engines.
Myth – Nothing can be done to keep birds away from airports.
Fact – There are a number of effective techniques that can reduce the number of birds in the airport area. In general, the techniques fall into three categories: making the environment unattractive for birds, scaring the birds, or as a last resort, reducing the bird population.
Myth – It is illegal to kill birds just to protect aircraft.
Fact – In North America, there are a few introduced (non-native) birds such as pigeons and starlings which are not federally protected species and generally may be killed if they pose a threat to aircraft. Most birds, such as ducks, geese, gulls, and herons, may be killed in limited number by an airport authority only after obtaining appropriate permits and demonstrating that non-lethal techniques are not adequate. Endangered species may not be killed under any circumstances.
Myth – If birds are a problem at an airport, killing them all would eliminate the problem.
Fact – Even if it were legal to do so, killing off all birds at an airport will not solve the problem. An airport is an integral part of the local ecosystem, and like in all ecosystems, each plant or animal species plays an important role. Eliminating any one problem species will only lead to some other species taking its place. A combination of bird control measures which take into account habitat management is a superior long-term solution.
Myth – Except for the very rare accident, bird strikes are only a nuisance to airline operators.
Fact – For a modern jet airliner, even minor damage can lead to significant costs. For example, if a bird strike results in damage that leads to replacing a single pair of fan blades, the airline has to deal with not only the direct cost of labor and materials, but also the indirect costs of keeping the aircraft out of revenue service and redirecting passengers. The FAA estimates that bird strikes cost civil aviation over $500 million per year in the USA, between 1990 and 2003. Worldwide, bird strikes cost commercial air carriers over $1 billion each year. Furthermore, minor damage to airliners is usually not covered by aircraft hull or engine insurance, so the costs of most bird strikes directly affect airline profits.
Myth – Bird strikes are a concern only to those who fly.
Fact – The issue of bird strikes is tied into a wide range of social and policy issues that go beyond aviation. The most important areas where this is true is the environment. Past and present policies of wildlife and habitat management can directly affect bird populations and bird strike hazards. Because bird strikes can lead to aircraft accidents, bird strikes can have a direct effect on both the families and friends of potential victims both in the aircraft and on the ground. Bird strikes can also have environmental consequences. For example, as a result of a bird strike that disabled an engine on a B-747 departing Los Angeles International Airport (LAX) in August 2000, the pilot had to dump 83 tons of fuel over the Pacific Ocean before returning to land safely at LAX.
Bonus Myth – Bird strikes never occur at high altitudes.
Fact – It is true that most strikes occur in the airport environment. About 41% of reported strikes with civil aircraft in the USA occur while the aircraft is on the ground during take-off or landing and about 75% of strikes occur at less than 500 feet above ground level (AGL). However, over 1,300 strikes involving civil aircraft at heights above 5,000 feet AGL were reported from 1990-2003. The world height record for a strike is 37,000 feet above sea level.