Flights Gone Wrong

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Bird Strikes Explained: How Often They Happen and the Defences

Aircraft in the US reported more than 24,000 wildlife strikes in 2025, but only a few per cent of those strikes cause damage, and very few have ever brought an airliner down. When one does, it is usually large birds in a flock hitting more than one engine, as on US Airways Flight 1549, which the crew ditched on the Hudson River in 2009 with all 155 people on board surviving.

Published 7 min read

Bird strikes are common and almost always harmless. The FAA’s annual wildlife strike report counted 24,447 wildlife strikes to civil aircraft in the US in 2025, but over 36 years only about 6 per cent caused any damage, a share that fell to 4 per cent in 2025. The rare strikes that bring an aircraft down usually involve large birds, in flocks, hitting more than one engine. US Airways Flight 1549 in January 2009 was one of them.

This guide explains how common bird strikes are, what a bird does to an engine, and how airports and engine makers defend against them. The US Airways 1549 videos are on the Bird strike page.

How common bird strikes are

The FAA and the US Department of Agriculture publish a report on wildlife strikes every year. The edition covering 1990 to 2025 shows:

  • 24,447 strikes reported in 2025, up 9.3 per cent on 2024, a faster rise than the change in aircraft movements.
  • 343,556 strikes reported from 1990 to 2025, almost all of them in the US. Birds were involved in the great majority, and mammals, bats and reptiles in the rest.
  • Most strikes happen low and near airports. About 71 per cent of bird strikes to commercial aircraft happened at or below 500 feet above the ground. Above that, the number fell by about 35 per cent for every 1,000 feet. More strikes happen on arrival than on departure.
  • Higher strikes do more harm. The report found that strikes above 500 feet were more likely to cause damage than those lower down.
  • Fatal strikes are rare. From 1990 to 2025, the report records 25 wildlife strikes in the US that killed a total of 52 people.

What a bird does to an engine

The greatest risk is to the engines, because a flock can reach more than one of them at once.

Engines are tested for this before they are certified. Under the US rule, 14 CFR 33.76, a single large bird is fired at the most critical part of the fan at 200 knots with the engine at take-off power. The bird’s weight depends on the size of the engine’s inlet: 1.85 kg (4.07 lb) for the smallest engines, rising to 3.65 kg (8.03 lb) for the largest. The pilot may not touch the thrust lever for 15 seconds afterwards. The engine does not have to keep running. It must not fail dangerously: no uncontained debris, no uncontrolled fire, and it must still be possible to shut it down. Separate tests cover flocks of small and medium birds.

The large-bird test, in other words, is about failing safely. It does not promise that an engine keeps running after swallowing a goose, and it says nothing about two engines being hit at once.

US Airways 1549 on the Hudson

On 15 January 2009, US Airways Flight 1549, an Airbus A320-214 registered N106US, took off from LaGuardia Airport in New York for Charlotte, North Carolina. It carried 150 passengers, including a child on a lap, and 5 crew.

The strike. At 15:27:10, about two minutes after take-off, the captain said “birds”. The flight data showed the aircraft was 2,818 feet above the ground, about 4.5 miles north-north-west of LaGuardia, when it flew into a flock. Both engines began to lose speed at once. The NTSB later identified remains of Canada geese in both engines. It noted that the average Canada goose weighs about 7.3 to 9.2 pounds. That is about twice the 4-pound bird the engines had been certified against at the time.

The decision. The crew started the auxiliary power unit and tried to relight the engines. Offered a return to LaGuardia, the captain replied, “we’re unable. we may end up in the Hudson”. Teterboro, in New Jersey, was considered and also ruled out. The captain told the controller, “we’re gonna be in the Hudson”. As the aircraft descended, the warning systems gave 15 alerts, including “terrain, terrain, pull up”. A pilot walks through the decision in US Airways Flight 1549: A Pilot Explains the Hudson Ditching.

The ditching. The A320 ditched on the Hudson River about 8.5 miles from LaGuardia. All 155 people on board got out through the forward and overwing exits. One flight attendant and four passengers were seriously injured. The evacuation is covered in US Airways Flight 1549: Brace Positions and the Hudson Escape.

What the NTSB found. The NTSB found that the probable cause was the ingestion of large birds into each engine, which caused an almost total loss of thrust in both engines and the ditching that followed. It credited four things with the survival of everyone on board:

  • the crew’s decision-making and crew resource management,
  • the fact that the aircraft happened to be equipped for long overwater flights, with forward slide/rafts, even though that was not required,
  • the cabin crew’s performance in getting everyone out quickly,
  • the emergency responders being close and responding at once.

The NTSB also noted that this was not a typical bird strike. Since 1960, 26 large transport aircraft had been destroyed by bird strikes worldwide, and 93 per cent of those strikes happened at about 500 feet or less, near an airport. Flight 1549 hit its birds at 2,800 feet, further out and higher than most. Two other airliners on this site that glided with no engine power, the Gimli Glider and Air Transat 236, are covered in Planes That Ran Out of Fuel.

The landing is one of the stories in When the pilots saved the plane.

An earlier case: Eastern 375

Eastern Air Lines Flight 375, Boston, 4 October 1960. Immediately after take-off from Logan Airport, a Lockheed L-188 Electra flew into a large flock of starlings at about 120 feet. Birds were ingested into three of its four engines. One engine was shut down. The other two lost thrust and recovered, but not at the same time. The aircraft lost speed and control and crashed. Of the 72 people on board, 10 survived. The Civil Aeronautics Board found the probable cause was “the unique and critical sequence of the loss and recovery of engine power following bird ingestion”. The FAA then started a research programme into bird ingestion. That led to the first engine certification guidance on birds, published in 1968.

This event does not have a page on this site yet.

The defences

  • Airport wildlife management. US certificated airports must carry out a wildlife hazard assessment after certain strikes, such as multiple strikes, substantial damage or birds ingested into an engine. The assessment can lead to a wildlife hazard management plan. LaGuardia’s plan, described in the NTSB report, targeted species such as Canada geese and had a bird supervisor on duty around the clock.
  • Reporting and identification. The FAA keeps a national wildlife strike database. The Smithsonian Institution’s Feather Identification Lab identifies birds from remains so airports know which species to manage.
  • Engine standards. Certification tests now cover large single birds and flocks of small and medium birds, with the bird weights set by engine size.
  • Pilot procedures and training. After Flight 1549, the NTSB examined how dual-engine failure checklists and ditching guidance were written. It found the Airbus dual engine failure checklist had been designed assuming the failure happened above 20,000 feet, so the crew could not get through it at low altitude, and that the FAA had approved ditching certification without checking that pilots could meet the ditching parameters with no engine power.

Why most strikes are harmless

Most strikes happen low and close to the runway. The FAA’s data reflects this: on average about 6 per cent of reported strikes caused damage, and about 4 per cent of bird strikes had any effect on the flight, most often a precautionary landing. Serious accidents need several things to go wrong together: large birds, a flock, more than one engine and little height or time. That is the pattern the Swiss cheese model describes. The bird strike topic page collects the events on this site.

For the full findings on Flight 1549, the NTSB report is listed below, and How to Read an Air Accident Final Report explains how such reports are organised. Terms used here, such as bird ingestion, are defined in our glossary.

Watch in the library

Every video on this subject is on the Bird strike page.

Sources

  1. Federal Aviation Administration: Wildlife Strikes to Civil Aircraft in the United States, 1990–2025 (FAA and USDA annual report, added 4 August 2026)
  2. Federal Aviation Administration: Wildlife Hazard Mitigation
  3. National Transportation Safety Board: Aircraft Accident Report NTSB/AAR-10/03, Loss of Thrust in Both Engines After Encountering a Flock of Birds and Subsequent Ditching on the Hudson River, US Airways Flight 1549, Airbus A320-214, N106US, January 15, 2009
  4. Federal Aviation Administration: Lessons Learned: Eastern Air Lines Flight 375, Lockheed L-188 Electra, N5533, Boston, October 4, 1960 (with the Civil Aeronautics Board’s probable cause)
  5. US Code of Federal Regulations (eCFR): 14 CFR 33.76, Bird ingestion

Last checked 31 October 2026.

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