Bird controlling radar to mitigate collisions at airports21 December 2017
The majority of bird collisions occur near or at airports. Future Airport speaks with Mogans Hanson, a wildlife biologist who has worked at Copenhagen Airport for 25 years, to find out what can be done to alleviate the problem.
Future Airport: How does wildlife in and around airports, particularly birds, currently affect safety standards?
Mogans Hanson: Safety standards are something the airport manager and the airport must follow. It is a matter of how the airport management can react and adapt to new or changing wildlife hazards and then rewrite the standards to cope with the situation. There are two different kinds of changes in bird appearances within airports. The first is the sudden kind, created by an abrupt change in the environment on or near the airport. You must react immediately to mitigate the arising hazard − it’s a kind of firefighting. The bird controllers are mostly the first eyewitness to such changes, and well-motivated and well-educated bird controllers will always react instantly to the new challenge by ‘fighting the fire’ and by warning the air traffic control (ATC). In such cases, it is important for the manager to have a clean line of communication with the Bird Control Unit.
The other change in appearance is the slow one. This is the gradual changes in wildlife populations. For instance, goose and cormorant populations in north-west Europe and North America are on a steady increase and due to climate change, there’s been some population change in their migration routes and wintering range. In such cases, you must be informed of these overall trends in bird population and compare this knowledge to what you are experiencing at your airport.
If you notice coinciding trends, you must react; however, you have a much better time to implement the right standards to counteract the increasing hazards.
What are the options available to airports in order to prevent bird strikes?
A basic wildlife risk management set-up is fundamental in order to control risk and reduce strike rates. Such a core set-up consists of effective habitat management, a fully equipped bird control, and running risk assessments of wildlife strikes and wildlife detected on or near the airport.
You must always keep your eyes open for new tools or technology and see how these can eventually be implemented to add a positive effect on bird hazard reduction work at your airport. I will not recommend any specific tool or technology because airports are different, and one tool is perhaps well functioning in one airport, but not in another. I would not recommend shocking tools employed automatically without the control of a bird controller. It is important that bird controllers have the full overview of the situation and are taking the decisions about how to react in the best way.
Overall, I recommend that airports to look at new IT technology. For instance, digital recordings of birds and of actions against birds is a great step forward, and the same is using GIS software to map and investigate sites on and near the airport. Such tools are making your work much more effective, are time-saving and provide you with the best kind of documentation for the efforts you are doing to reduce the bird strike risk.
How should airports implement deterrent and prevention technology in order to continue safe operations?
Firstly, airports must make it clear for themselves whether a new technology can, in fact, be used to solve specific problems they may have. Secondly, the users, for example, the bird controllers must have a full understanding of why, how and when to use a new deterrent technology. It is a matter of insight.
Before you intend to implement new technology, you must perform a formal risk assessment of the introduction of the technology: which benefits can be achieved and, if you expect some negative side effects on the overall safety level, how you can mitigate these effects.
It is very easy just to implement a new tool, but it is very difficult to reject it again if it fails to be a success. Then you must document why this tool fails to have the intended effect and you must formally assess the consequences for the bird strike risk when the tool is no longer in use.
How have bird radars improved airport safety and efficiency?
A bird radar is just a tool, it is not a solution. A radar can’t deter birds, but it can help airports to take much more targeted deterring and mitigating actions. However, it requires that the airport can read the radar and translate the data it delivers to concrete actions to improve safety. I think this is the biggest challenge for an airport.
A bird radar can provide three main functions. Firstly, the bird controller sitting in the vehicle can watch on a screen where the risky birds are settling on the airfield here and now. Then the bird controller can move directly to the hot spots and deter the birds. Such an approach will markedly reduce the time birds can spend unnoticed on the airfield.
This has several obvious advantages: the birds are driven from the airport and no longer induce a risk, and if the same birds are deterred regularly shortly after they have entered the airfield, they will experience a deficit in their energy budget if they do not choose an alternative feeding site. This is quite a new strategy for an airport bird control unit, and is leading to more efficient control of birds on the airfield – if this approach is well performed it will reduce the number of strikes.
Secondly, radar tracks can be stored and this historical data can be analysed to determine where birds are coming from and where they are settling near the airport. Thus, you can identify high-risk sites outside of the airport.
Thirdly, you can detect actual bird movements. Most people think that this is the primary advantage of a bird radar, and that aircraft can avoid collisions with birds if a radar can warn the pilot. However, this is more a dream than a fact. We must realise that there is a time lag of several seconds from the rotating radar receiving an impulse from a detected bird, and further reaching the computer, and finally for the computer to transform impulses to a readable message. So, the message you see is no longer in real time, it is several seconds old and the bird will have moved a few metres ahead since then. Moreover, if the human reaction time for alarming is 30 seconds and the bird’s flight speed is 60km/h, the bird has already flown a further 500m.
There is another aspect. Birds’ flight paths are not always in a straight line and their flight speed can vary from time to time.
A flock of geese can suddenly change the flight direction and the flight height. Such a flock is unpredictable, and you can then use a radar track line of the birds for your conclusive decision: stop or go for an aircraft. To be safe, you must have a large margin of many kilometres without flocks of large birds before you declare go. So, we can imagine a reduced capacity of aircraft operations at that airport if a bird migration is proceeding in the vicinity. And who will then take the responsibility to say stop or go to the pilots? Fortunately, most birds react to operating aircraft and take evasive flight manoeuvres to avoid a collision, especially as geese are very alert to aircraft and react to them even at a distance of several kilometres in front. However, if you imagine that a bird flock could be detected in the periphery on the radar screen and the pilots were not warned, what would be the consequences if they in fact collide with an aircraft and posed a high-cost damage? Is the airport company, or the ATC, or others judicially responsible for the damage?
What are some of the key factors to be considered when specifying requirements for bird detection radar?
This is a difficult question because it depends on what kind of bird radar you are looking at – a 2D or a 3D bird radar – and then we have to look at their covering range. However, the radar should detect all birds and reject all misleading images. The radar should also discriminate between flocks and single birds, and between large birds, medium and small ones. Another key factor is the range the individual radar can cover. Far range coverage is of course the optimal solution if you are also exploring the vicinity of the airport. Further, the radar should treat the data fast and deliver it in an easily readable way for analysis.
How does radar compare with the alternatives?
There is only one other alternative to detect bird movements over a larger distance than a bird radar. This includes satellite tracking of birds attached with transmitters; however, this is quite a different use case.
I remember the old studies of bird migration when a long line of ornithologists are sitting kilometres apart detecting and mapping a specific flock of birds using walkie-talkies to inform each other where the flock actually was. Such studies cannot bear comparison in effectiveness with the use of a bird radar.
What advice would you offer to airports that are looking to implement new technology in order to prevent bird strikes?
I will just emphasise my message – be careful when you intend to implement new technology, be sure that the particular product fulfils your needs and at the right cost price. My best advice is to try the product before you decide on it and before you implement the product in your wildlife hazard management programme.