In the worst case, a bird can penetrate like a bullet through the aircraft's windshield and cause serious injuries to the pilot. Additionally, the windshields of smaller aircraft and helicopters are designed to withstand minimal loads and can easily break. It is interesting to note that a heated glass absorbs impact energy better. The higher the relative speed between the bird and the aircraft, and the greater the bird's mass, the worse the damage caused by the impact will be.
In most cases, only one bird is struck at a time, so the collision is not strong enough to cause visible damage to the aircraft. However, we must land as soon as possible, because an accurate assessment of the damage can only be made on the ground.
Abort the takeoff if there is enough runway to do so. In most cases, it is not possible to precisely determine what happened, which is why it is necessary to return to the ramp area to conduct a thorough inspection of the aircraft.
If aborting the takeoff is not feasible, the aircraft should return to the ground as soon as possible. If the bird strike has caused an engine problem, the appropriate emergency procedure for the circumstances should be followed. In any case, it must be reported to the airport, and the aircraft should return to the field.
If obvious structural damage or damage to the control surfaces has occurred, the most reasonable course of action is to assess the aircraft's maneuverability before landing. This check should be carried out at a safe altitude and with an appropriate speed.
INFORMATION ABOUT BIRD STRIKES
In the Aeronautical Information Publication (AIP) of a given country, in Chapter 5.6 of the “En Route” section, there is a section dedicated to bird concentrations and their migration patterns.
Always check the NOTAMs for bird strike risk information before each flight. These special NOTAMs may be published under the name BIRDTAM.
PRE-FLIGHT INSPECTION
Pilots are not always aware of bird strikes, so they may not report them. A bird may have inadvertently become lodged under the engine cowling or damaged a pitot tube. Whenever a visual inspection of the aircraft is conducted, attention should be paid to possible bird-related damage.
In spring, special attention should be given to pre-flight inspections because birds may have built nests overnight. If we observe grass or small branch remnants, an additional inspection should be carried out, even in less accessible areas. A nest under the engine cowling can catch fire, and a nest in the tail may compromise the control cables.
OBSERVE BIRD ACTIVITY AT THE AIRPORT
During taxiing, we must be attentive to birdlife on the aerodrome. Due to their plumage and size, some birds can be hard to distinguish on concrete or asphalt. There may also be a warning about bird activity in the ATIS.
SPECIAL CARE IN APPROACH/LANDING
When large concentrations of birds are expected near an aerodrome, steep approaches or higher-than-normal approach speeds should be avoided. Reducing speed by 30% results in half the impact energy.
If flocks of birds are present in the approach area, a go-around should be executed well in advance. The next approach may be free of birds.
In the particular case of vultures, which are often found flying straight and at higher altitudes, it should be noted that these birds focus their attention on the ground, so we should not assume that they have noticed the aircraft.
Evasive manoeuvres:
• Never overtake or cross below vultures. Vultures, when faced with an unexpected threat, fold their wings and initiate a steep descent. To overtake them or cross paths, do so above them; if not possible, overtake them while maintaining sufficient horizontal separation.
• If encountering vultures head-on, the safest evasive maneuver is to gain altitude by pulling on the control stick, as vultures do not have as much climbing capacity; the vultures will avoid us by descending. Pulling up reduces our speed.
• When ascending, the aircraft's wings protect against impact with the tailplane, the cockpit, and the engine—the weakest parts of the aircraft.
• Adopt the same turning direction as the vultures in the thermal updraft.
• Vultures use thermal and slope updrafts for their flight, which means we should be especially vigilant during the central hours of the day.