Frequently Asked Questions
A collision between an aircraft and an animal. This can occur during any phase of flight; however, they mostly occur when aircraft are arriving and departing airports because the plane and animal are occupying a common space.
No. Although flying animals (birds and bats) are involved in the majority of strikes, other animals are commonly struck. Strikes can occur when aircraft are moving on runways and taxiways where they may encounter reptiles, rabbits, foxes, domestic animals, and a range of other terrestrial mammals such as kangaroo, deer and coyotes.
Whilst most strikes are not serious, they can result in significant injury to people and damage to aircraft, and in worst case scenarios, human fatalities and destroyed aircraft. A number of factors contribute to serious strikes, including the number and type of animals involved, the aircraft type, the speed of impact and the part of the aircraft struck.
Simply put, they occur because aircraft and wildlife can occupy the same space at the same time. The number of wildlife on and in the vicinity of airports can vary considerably depending on the availability of food, water and shelter.
Airports usually employ a combination of active and passive techniques to reduce the number of wildlife. Active techniques involve a range of tools to disperse wildlife from the airfield such as pyrotechnics, distress callers, lights, sirens and stockwhips. Passive management focuses on modifying the airside environment to reduce the wildlife attraction. This may include carefully selecting vegetation to exclude certain plants and grasses, removing or modifying drains to reduce water access, and installing netting or anti-perching spikes on buildings.
Airports offer large areas of short grass, which many birds and other animals prefer because they can forage safely while keeping an eye out for predators. Airports also offer a relatively predator-free environment thanks to their high perimeter fences and the general activity of aircraft and other vehicles. Airports can also provide access to a reliable water source from drains and other water retention areas, and access to food.
Birds and bats that fly over airports to access areas nearby can also present a strike risk; however, managing these animals and off-airport areas requires a different approach with close collaboration between the airport and land users.
Airports generally don’t aim to eliminate wildlife strikes. This is impossible if birds and aircraft continue to occupy the same space, particularly when the risk comes from off-airport areas (e.g. a landfill) which falls outside the airport’s jurisdiction. Instead, airports aim to manage the strike risk to as low a level as possible. This is achieved when an airport implements an integrated management program that:
- employs active and passive techniques
- assesses wildlife strike risks
- communicates hazards to pilots
- uses trained and equipped personnel
- works with off-airport land users and planning authorities
- monitors wildlife
- reports strikes
This varies considerably and is usually measured by airports by the rate of strikes for every 10,000 aircraft movements. In Australia, for example, this rate is X strikes/10,000 aircraft movements.
In general, wildlife strikes occur at a higher rate than most other common aviation incidents.
This depends on where the airport is located (which is influenced by seasons and local wildlife populations), and when aircraft movements are scheduled. Some airports have significant wildlife hazards at night (e.g. bats); others experience annual peaks in wildlife numbers due to migratory birds; and many airports experience heightened wildlife activity at the beginning of the day.
In civil aviation, around 93 per cent of strikes occur at below 3500 feet above ground level. This is because when aircraft are approaching, landing, taking off and departing airports, they are low enough to be in the same space where birds generally operate.
In November 1975, a Ruppels Griffin Vulture (Gyps rueppellii) intersected a Boeing 747 at 37,000 feet over Cote d’Ivoire, West Africa, destroying an engine. The crew landed safely with no human fatalities. Strikes at this altitude are very uncommon.
Sadly, yes. As of July 2020, wildlife strikes have caused 532 human fatalities since the beginning of aviation in the early 1900s.
Despite the ‘Miracle on the Hudson’ (Flight 1549 out of La Guardia Airport (New York) in January 2009) being one of the most well-known incidents, it is far from the deadliest strike. The worst fatal strike on a civilian aircraft occurred on 4 October 1960 when Eastern Airlines flight 375, a Lockheed Electra, struck a large flock of European starlings 20 seconds after take-off from Boston International Airport. The birds struck three of the four engines, with the aircraft losing power and crashing into the nearby Boston Harbour. Of the 72 people on board, only 10 survived.
As of July 2020, wildlife strikes have destroyed 614 aircraft since the beginning of aviation.
Wildlife strikes cost the commercial civil aviation industry an estimated US$1.2 billion per annum and involve more than just the repair of damaged engines and airframes. Even apparently minor strikes which result in no obvious damage can reduce engine performance, cause concern among aircrew and add to airline operating costs.
The first known wildlife strike was recorded in the diaries of the Wright brothers. The entry detailed how Orville Wright chased a flock of birds on 7 September 1905 and struck one.
Only a few short years later, on 3 April 1912, aviation pioneer Calbraith Rodgers collided with a gull which became jammed in his aircraft control cables. He crashed at Long Beach California, was pinned under the wreckage and drowned. This was the first recorded aviation fatality due to a wildlife strike.
Yes! Inappropriate land use around airports can attract significant numbers of wildlife raising the risk of an airport having bird strikes. Because of this, the International Civil Aviation Organization requires authorities to eliminate or prevent the establishment of landfills, or other sources of wildlife attraction, in the vicinity of airports.