Date of this Version
Presented at 2011 Bird Strike North America Conference, September 12-15, 2011, Niagara Falls, Ontario, Canada.
Birds will continue to be a hazard to aircraft operations until one or the other stops flying. Not a likely scenario. Aircraft continue to have encounters with birds despite the best efforts of airport staff everywhere. Experts have found ways to reduce available habitat, identify roosting areas, use radar to track movement and analyze DNA to identify the species being struck, but risks remain. The problem with the current system is people taking the risks, the aircrew and owners, have the least amount of information available to make an accurate risk decision.
Tune in the ATIS at almost any civil airfield and you will hear the weather, some local NOTAMs and that there are “birds in the vicinity of the airport”. This last statement provides no actionable information to a flight crew. It is therefore impossible for a flight crew to properly assess the risk posed by the birds. Imagine tuning in the traffic report on your commute to work and hearing the announcer say, “Vehicles in the vicinity of the city”. How much help is that for your commute? Are there thousands of cars on the road and traffic is backed up everywhere or are there only a few vehicles around and it’s smooth sailing? The information given makes it difficult to determine which route to take or if you should even attempt the drive at all. There just aren’t enough details to make a decision. This is exactly the position flight crews are placed in every day.
The current advisory statement about bird activity is vague and fails to provide an accurate indication of the risk posed by current bird activity. Are there only a few birds sitting on the perimeter fence (low risk), or is an entire flock gathered around the approach end of the runway (high risk). This information is crucial to the pilot. In order to make an informed decision on a course of action the pilot needs accurate information on the potential risk. A better system to inform aircrews of the risk associated with bird activity needs to be implemented.
The U.S. Air Force uses a Bird Watch Condition (BWC) code to alert flight crews of hazards created by bird activity at the airfield. The different codes have specific meanings and associated risk. The following is an excerpt from AFI 91-‐ 2021:
SEVERE. Wildlife activity on or immediately above the active runway or other specific location representing high potential for strikes. Supervision and aircrews must thoroughly evaluate mission need before conducting operations in areas under condition SEVERE.
MODERATE. Wildlife activity near the active runway or other specific location representing increased potential for strikes. BWC MODERATE requires increased vigilance by all agencies and supervisors and caution by aircrews.
LOW. Wildlife activity on and around the airfield representing low potential for strikes.
These definitions could serve as either a template or a point of departure to develop a standard BWC for all airports.
NATO has also developed a standard warning scale to help aircrews assess the risk of a bird strike. These warnings are known as BIRDTAMs2. According to NATO STANAG 3879 a BIRDTAM will be sent during bird migration season and anytime the intensity is 5 or greater3. BIRDTAMs are available via the internet to any aircrew flying in the coverage area.
Creation of a standard BWC will have the added benefit of allowing companies, through their Safety Management System (SMS), to determine the risk they are willing to accept. Companies can dictate what actions a flight crew should take based on the risk associated with each BWC in their operations manual. Using SMS, a company can further delineated crew actions based on the type of flight; a company executing an emergency air evacuation flight may be willing to accept more risk than a company performing a transportation flight. Publishing the expected actions for each BWC in the ops manual ensures the risk decision is made at the appropriate level, one of the basic tenets of Risk Management and SMS.