For Airport Operators

A central role in prevention

Airport operators play a leading role in wildlife strike prevention. National and international regulations assign them direct responsibility for managing wildlife hazard risk within the aerodrome and surrounding areas, through a comprehensive set of activities ranging from environmental surveys to day-to-day operational management.

This responsibility stems from the recognition that 80% of strikes occur within or in the immediate vicinity of the aerodrome, and that the aerodrome environment — with its extensive grassed areas, water availability and relative tranquillity — can be highly attractive to numerous wildlife species.

Regulatory requirements

The Regulations for the Construction and Operation of Airports and Circular APT-01B define a comprehensive set of obligations for operators of certified aerodromes:

• Wildlife and environmental survey: every certified aerodrome must have a survey incorporating a risk assessment describing the ecological characteristics of the site and surrounding area, identifying the species present and the main attractants, assessing the risk level and proposing mitigation measures. The survey must be carried out by professionals, institutions or bodies with documented specific expertise in the field. It is valid for five years and must be approved by ENAC–BSCI.
• Prevention and control plan: on the basis of the survey, the operator must prepare a procedure defining the actions taken to prevent or minimise the risk of wildlife strike. The plan is an integral part of the Aerodrome Manual and must identify the responsible organisational structure.
• Bird Control Unit (BCU): every aerodrome must have a service for wildlife control, monitoring and dispersal (BCU). The BCU must exercise continuous surveillance — not only at the moment of dispersal — and ensure complete clearance of birds prior to landings and take-offs. At major aerodromes (more than 50,000 movements per year), BCU personnel must not hold any other duties during their watch.
• Monitoring and BRI calculation: the operator must conduct systematic wildlife presence monitoring and calculate annually the Birdstrike Risk Index (BRI), developed by ENAC–BSCI in collaboration with Ca’ Foscari University of Venice.
• Event reporting: every wildlife strike event must be reported through the ECCAIRS2 system.
• Reporting of external attractants: the operator is responsible for identifying potential wildlife attractants in areas adjacent to the aerodrome and reporting them to ENAC and the relevant local authorities.
• Collection and submission of biological samples to I.B.I.C.: the operator is required to collect biological remains (feathers, tissue, blood traces) found in connection with every wildlife strike and to submit them to the Italian Birdstrike Identification Center (I.B.I.C.) for taxonomic identification to species level.
• Annual report: the operator must prepare and submit to ENAC–BSCI an annual report containing analysis of data relating to reported events, wildlife monitoring data, mitigation measures in place, the BRI value and the trend over the preceding three years.

Management of external attractants

In addition to managing risk within the aerodrome, regulations require operators to monitor and report wildlife attractants present in surrounding areas. Animals drawn to specific facilities or activities in the vicinity of the aerodrome may move into the aerodrome itself or cross aircraft movement corridors, increasing the risk of strikes.

Guidelines LG 2018/002 provide guidance for the assessment and management of these external attractants, defining three concentric zones around the aerodrome’s runways, each with specific requirements.

Safeguarding zones

Guidelines LG 2018/002 — “Wildlife strike risk management in the vicinity of aerodromes” — define three concentric zones measured from the aerodrome’s runways. Since the vast majority of strikes occur below 2,000 feet above ground level, and an aircraft normally reaches this altitude at approximately 13 km from the runway, this distance represents the maximum radius within which wildlife attractants must be monitored.

Requirements vary according to the risk level of each attractant (high, moderate, low) and the distinction between existing sources and proposed new activities:

The identification and monitoring of attractants within 13 km of the aerodrome is the responsibility of the airport operator, who must report them to ENAC and the relevant local authorities. ENAC may order, by reasoned provision, the removal or elimination of existing facilities and activities where these are incompatible with the safety of air navigation and where their effects cannot be mitigated.

The Birdstrike Risk Index (BRI)

The Birdstrike Risk Index (BRI) is the composite indicator adopted by ENAC–BSCI to measure the wildlife strike risk level at each aerodrome. The index takes into account both the frequency and the severity of strikes: frequency is related to air traffic volume, the number of animals present and their behaviour; severity is related to the number of strikes, the species involved (in terms of body mass) and the effects on the flight.

For the calculation of the BRI, 17 functional species groups have been identified, characterised by shared ecological, behavioural and physical characteristics. Strike severity is classified into 5 levels, in line with ICAO guidance.

Alert threshold: BRI > 0.5

An alert threshold of 0.5 has been established on a statistical basis. When the annual BRI value exceeds this threshold, the operator is required to analyse the causes of the increase and to activate additional corrective measures.

Even in the absence of a threshold exceedance, if the BRI trend over the preceding three years shows an upward pattern, the operator is nonetheless required to analyse the causes and to intensify monitoring and environmental management and active dispersal activities.