A bird strike—sometimes called birdstrike, bird ingestion (for an engine), or bird hit, —is a collision between an airborne animal (usually a bird or bat) and a human-made vehicle, especially aircraft. The term is also used for bird deaths resulting from collisions with human-made structures such as power lines, towers and wind turbines (see Bird-skyscraper collisionsand Towerkill). A bug strike is an impairment of an aircraft or aviator by an airborne insect.
Bird strikes are a significant threat to flight safety, and have caused a number of accidents with human casualties. The number of major accidents involving civil aircraft is quite low and it has been estimated that there is only about 1 accident resulting in human death in one billion (109) flying hours. The majority of bird strikes (65%) cause little damage to the aircraft; however the collision is usually fatal to the bird(s) involved.
Most accidents occur when the bird hits the windscreen or flies into the engines. These cause annual damages that have been estimated at $400 million within the United States of America alone and up to $1.2 billion to commercial aircraft worldwide.
Here is a short video showing some types of damage caused by bird strikes!
Before we look at some of the key themes for this unit, take a moment to study the photograph below and see if you can describe what you can see for 90 seconds.
Key Themes and Vocabulary
Birds are a great risk to aviation especially when they are encountered at a low altitude, they can obviously be found in all legs of the traffic pattern (Upwind, crosswind, downwind, base and final) and along departure and arrival routes. Good airmanship requires us to advise the tower and other aircraft of the position of flocks of birds. We also find birds on taxiways and at the ends of runways. It is not unknown to find some migratory birds at high altitude too, birds migrating accross the atlantic have been reported at Flight Levels of up to FL380!!!!
- Traffic PatternCircuito de Tráfego
- Flock of BirdsBando de Pássaros
We might encounter a single bird during our flight from time to time, or we might encounter a group of birds, a group of birds is called a “Flock” and the term flock can often be heard on ATIS reports. when describing the size of a flock we speak subjectively. “Tower PlaneEnglish 123, Large flock of birds at 1000ft on the downwind leg” or it might be a small flock of birds, or, if you consider it to be an average flock of birds, just say…. Flock of birds!
- Single BirdPássaro Único
- From Time to TimeDe Vez em Quando
Note on Grammar. A small flock of birds IS NOT the same as a flock of Small birds. If you would like to know the difference, send Professor Paul a message via SMS or Whatsapp on (61) 81373051
Below is a photo of a British Airways 757 passing near to a flock of birds, describe the photo in as much detail as you can!
Names/types of birds
In the exam, you will not be expected to be able to name all names and types of birds, but it would be beneficial to be able to name some!
Hawks and Falcons are often used at airfields to control the populations of smaller birds, hawks and falcons are “Predatory Birds” in that they hunt and attack smaller birds.
If you need an example of large birds, you could use Vulture (Urubu) or Goose (Ganso) a vulture is a predatary bird theat preys on others, a goose (plural geese) is a migratory bird.
Examples of smaller birds would be Starlings and Thrushes
- Goose (Geese)Ganso (Gansos)
Some larger airports, such as Galeão, use Flares to scare birds, flares are a specific type of firework (Fogo de artifício) that create light and a loud “BANG” that causes birds to leave the area. Often during the bird scaring procedure departures and arrivals are put on hold for a perdiod of a few minutes whilst the sky is full of birds!
The photo below is of a man setting of flares to scare birds, describe the picture in as much detail as you can!
Damage to aircraft
Bird strikes can cause all sorts of damage to an aircraft, obviously depending where the bird hits. The worst case scenario is to ingest a bird in to one or even both engines causing the engine(s) to shut down. Bird strikes to the windshield can cause the windshield to crack or might affect visibility due to the blood and bird parts on the windshield. Birdstrikes to the leading edge of the wings can disrupt the airflow over the wings and reduce lift. It is quite common for birds to hit the Radome on the nose of the aircraft, this would cause the radome to malfunction and make weather detection impossible. Another problem could be if the bird collides with the landing gear, this might cause problems when trying to retract the landing gear if the bird becomes caught in the mechanism.
- All Sorts ofTodos os Tipos de
- Shut DownDesligar
- Leading EdgeBorda de Ataque
- Reduce LiftReduzir o Sustanção
- Disrupt AirflowInterrompa o Fluxo de Ar
Behaviour of Birds
Flocking behavior is the behavior exhibited when a group of birds, called a flock, are foraging or in flight. There are parallels with the shoaling behavior of fish, the swarming behavior of insects, and herd behavior of land animals. When threatened a bird will descend, meaning that in a potential birdstrike situation it is best to try to climb over the bird – In summary, the birds “natural TCAS” will always say “TRAFFIC TRAFFIC DESCEND DESCEND”
- FlockBando (de Pássaros)
Case Study – US AIrways 1549
US Airways Flight 1549 was an Airbus A320-200, registered N106US, operating a US Airways scheduled domestic commercial passenger flight from LaGuardia Airport in New York City to Seattle–Tacoma International Airport in SeaTac, Washington, with a stopover at Charlotte/Douglas International Airport in Charlotte, North Carolina. On January 15, 2009, at 3:27 p.m. EST, the plane struck a flock of Canada Geese during its initial climb out, lost engine power, and ditched in the Hudson River off midtown Manhattanwith no loss of life.
The bird strike, which occurred just northeast of the George Washington Bridge about three minutes into the flight, resulted in the rapid loss of thrust from both engines. When the crew of the aircraft determined that they would be unable to reliably reach any airfield, they turned southbound and glided over the Hudson, finally ditching the airliner near the USS Intrepid museum about three minutes after losing power. All 155 occupants safely evacuated the airliner, which was still virtually intact though partially submerged and slowly sinking, and were quickly rescued by nearby ferries and other watercraft. The incident became known as the “Miracle on the Hudson”.
The entire crew of Flight 1549 was later awarded the Master’s Medal of the Guild of Air Pilots and Air Navigators. The award citation read, “This emergency ditching and evacuation, with the loss of no lives, is a heroic and unique aviation achievement.” It was described by NTSB board member Kitty Higgins as “the most successful ditching in aviation history.”
Case Study – Thomson 263H
In April 2007, a Thomsonfly Boeing 757 from Manchester Airport to Lanzarote Airport suffered a bird strike when at least one bird, supposedly a heron, was ingested by the starboard engine. The plane landed safely back at Manchester Airport a while later. The incident was captured by two plane spotters on opposite sides of the airport, as well as the emergency calls picked up by a plane spotter’s radio