Disastrous collisions between birds and flying aircraft are a permanent and serious threat, but fortunately, they are relatively rare. They are a particular danger to small aircraft, especially single-engine types. Larger multiple-engine jets are more able to absorb the impact of birds, even large species such as the Kori bustards (Ardeotis kori), native to eastern and southern Africa, which can weigh up to 19 kilogrammes. With a wingspan of up to 2.75 metres, a male Canada goose usually weighs 2.6–6.5 kilogrammes. Large flocks of smaller birds, such as gulls or even pigeons, can also be a danger to aircraft landing or taking off.

While most bird strikes result in minimal damage, larger birds or flocks can cause significant damage to engines, wings, or windshields. Bird strikes happen frequently, but the vast majority are not serious, with aircraft landing safely with little damage. However, birds can damage both jet and propeller engines, potentially leading to engine failure or requiring repairs. Jet engine ingestion is extremely serious due to the rotation speed of the engine fan and engine design. As the bird strikes a fan blade, it can damage other blades in turn and the engine may flame out. Birds can also damage wings, windshields, or nose sections, potentially requiring repairs or inspections. Such collision damage can lead to considerable financial loss for airlines involving repairs, lost flight time, and potential delays checking for Barely Visible Impact Damage (BVID). Avian collisions have been estimated at an annual cost of US$1.2 billion for commercial aircraft worldwide.

Notable accidents

In 2023, a B-737 Max 8 experienced engine shutdown and damage to its radome after colliding with turkey vultures, resulting in an emergency landing and extensive repairs.

“Miracle on the Hudson” where Captain Chesley “Sully” Sullenberger successfully performed an emergency landing of US Airways Flight 1549 on the Hudson River after a flock of Geese collided with the aircraft shortly after taking off from New York’s LaGuardia airport

On 30th December 2024, a bird strike was partially blamed for the fatal accident of Jeju Air Flight 7C2216, which crashed in South Korea in December, killing 179 people.

In the US, wildlife strikes, including bird strikes, were reported to the Federal Aviation Administration (FAA) more than 19,600 times in 2023. Some of these involve collisions with other animals, such as deer. In Britain, an estimated 40,000+ deer are killed or injured in vehicle collisions annually, causing substantial damage to vehicles, numerous human injuries, and several fatalities. Not to mention the loss of wildlife.

Environment

Airports’ open areas may attract birds for nesting and feeding grounds, and if there are any lakes or water features within the airport perimeter or nearby, waterfowl, gulls, and raptors are more likely to be involved in bird strikes. As planes take-off and land, bird strikes are more common. During take-off and landing, when aircraft are flying lower to and from runways, is the most dangerous moment of flight, and the Airport Services Association (ASA) recommends flying at a minimum of 2,500 feet where possible, which clearly does not apply at take-off and landing. For every 1000-foot increase in cruise altitude, there is a significant reduction in the risk of a bird strike. However, collisions can occur at high altitudes 6,000 to 9,000m (20,000 to 30,000 ft) above the ground. Bar-headed geese have been seen flying as high as 10,175 m (33,383 ft) above sea level. An aircraft over the Ivory Coast collided with a Rüppell’s vulture at an altitude of 11,300m (37,100 ft).

Airport Managers are forever trying to implement deterrents, such as habitat modification, introducing predators, and noisy explosions.  But birds quickly adapt to many of these measures. While aircraft manufacturers are constantly working to improve aircraft designs to minimise the impact of incidents, death and injury are of deep concern about the rapid decline of many bird species. The largest number of strikes happens during the spring and autumn migrations. Bird strikes above 500 feet (150 m) altitude are about seven times more common at night than during the day during migration. The Smithsonian Institution’s Feather Identification Laboratory has identified turkey vultures as the most damaging birds, followed by Canada geese and white pelicans, all of which are very large birds. In terms of frequency, the laboratory most commonly finds mourning doves and horned larks involved in the strike. The remains of the bird are called snarge, especially from a turbine engine are sent to identification centres where forensic techniques may be used to identify the species involved. With the emphasis on cutting emissions coupled with the increasing demand for foreign travel, the destruction of so many wild creatures tends to be relegated to low importance, but the loss of species on land, sea and air is causing worrying long-term harm to the global environment.

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