A wildlife strike is a collision between an animal and an aircraft which is in flight or on a take off or landing roll. The term to describe such events was initially bird strike since this was the most common scenario. However, the increased number of flights and airfields used resulted, among other things, in the increase of collisions between aircraft and animals other than birds.
Wildlife strikes may occur during any phase of flight but are most likely during the take-off, initial climb, approach and landing phases. The reason is that most birds fly at lower levels and other animals (except bats) can only hit an aircraft while on the ground.
Aircraft size - smaller aircraft can withstand less damage before the safety of flight is compromised and are generally more vulnerable.
Animal size and weight. The weight of an animal is directly proportional to the energy to be absorbed in an impact.
Speed during impact - the kinetic energy to be absorbed is proportional to the square of the relative speed of the two objects. Normally the aircraft is much faster and therefore the animal speed can be disregarded.
The defences against animal strike include measures to:
Prevent the event from happening. This includes perimeter fencing to make the aerodrome inaccessible to non-flying animals as well as measures to make it less attractive to birds, e.g. reduction of plants that may provide food or shelter, grass management, employment of bird scaring techniques, etc. More detail can be found in the article on Airport Bird Hazard Management.
Observation of the manoeuvring area for birds and other animals and provision of information to flight crews. Detection can be visual (by the controller or dedicated checks by aerodrome personnel) or by using technical aids. Information may be passed by the controller or using ATIS or BIRDTAM.