By Amanda Foxton-Hill
Did you take part in the Aussie Backyard Bird Count from 17th to 23rd October? I did and my two (yes I know, only two) checklists have gone on to join the 44,707 others submitted so far in what will hopefully turn out to be a great triumph of citizen science.
Birds have been on my mind a bit lately. You see I live in the Blue Mountains, an area that, should the Environmental Impact Statement (EIS) for the Western Sydney Airport be approved, will have an open-all-hours airport located just 8km from its border. As someone who delights in the abundance and variety of birdlife in my backyard I had held the belief that the mountains had been thoroughly surveyed before such a major piece of infrastructure got this far. Especially given that the way the airport is planned makes it impossible for planes not to fly at relatively low altitudes over the national park and, of equal importance, Sydney’s largest drinking water supply, Warragamba Dam! But sadly I seem to have been mistaken. In fact, the mountains warranted only a passing mention in the official bird and bat strike section which goes on to rank this potential new airport as having a low risk of bird and bat strike. I find this rather odd and a little un-nerving. This disquiet has prompted me to delve a little deeper in a bid to establish whether this ‘low’ risk status is, in fact true or is it more of a case of wishful thinking?
Birds and Airports don’t mix.
Have you see the film Sully yet? This film centers on what happens when birds and planes meet. In this case it was a flock of Canadian Geese – we don’t get Canadian Geese in Australia BUT what we do get are Lapwings (Plovers), Ibis, Flying Foxes, Galahs, Kites, Magpies, Kestrels and many other birds that can either alone or in their flocks spell trouble and great expense for the aviation industry. Like many other people who carried out that bird survey I mentioned earlier, these ‘aviation problem’ birds were spotted and noted in many of the suburbs surrounding this proposed airport.
Bird strike is just as much a problem here in Australia as it is overseas and the Australian government’s website states that between 2004-2013 there were 14571 bird strikes on planes, a number that is rising in step with our increased love of air transportation.
I thought it would be interesting to see what October 2016 looked like in terms of bird and bat strike globally with a view to gaining a wider perspective of this issue and give some real data, a snapshot in time! So here are just the last few weeks!
21st October 2016 A330-200 travelling from Sao Paulo to Lisbon, suspected bird impact to engine. Fuel dumped and returned to origin within an hour of take off.
21st October 2016 B737 at Fort Lauderdale, rejected takeoff due to bird strike. 3.5 hour delay.
21st October 2016 Fedex B763 at Rochester, suspected flap damage, dead birds found on departure runway.
16th October 2016 Salt Lake City, Delta B739 bird strikes upon landing. 3 hour delay for ongoing flight.
11th October 2016, Southwest B738, rejected takeoff due to a bird strike. plane was replaced after a 2 hour delay.
6th October 2016 Alitalia E175 Engine damage from bird strike at Milan. Plane continued to Palermo but was unable to take off for its return flight.
6th October Qantas B744 at San Francisco. Bird strike to landing gear door strut. Plane made it to Sydney without incident.
It has been estimated that there are 100,000 scheduled commercial airline flights per day worldwide, so from 1st – 21st October there would have been around 2.1 million flights and 7 incidents – that’s 3.33 incidents per 10,000 flights which sits within the range of strikes seen at Australia’s major airports (the EIS reports this to be between 3.13 strikes – 10.96 strikes per 10,000). So with that in mind it looks like my October data can be seen as representative of what happens ‘out there’.
I was somewhat comforted by the fact that the above incidents involved financial and time losses rather than anything more sinister but then I remembered that HW Heinrich incident safety triangle they teach you about when you work in a factory (I’m an industrial chemist) and my optimism cooled once more. I wonder if we have become a bit too complacent being as though most bird and bat strikes don’t actually kill people?
What the airport can control and what it can’t.
So now I have an idea of what can and does regularly happen I put on my management hat and looked into what can and can’t be directly managed and controlled. This is a tale of two ‘cities’ so to speak:
- The airport Proper.
- The airport Environment.
The airport proper is the actual space owned and managed by the aerodrome. In this case 17 square km of space, which is double the space that Sydney Kingsford Smith currently uses. I found out that there are strict guidelines of how the airport proper is to be managed to make it as unfriendly to birds and bats as possible. Throughout the planning stages and during operations this space is actively managed to keep foreign bodies (including bats and birds) out. Therefore minimizing the risks of a strike. Most bird and bat strikes occur at heights of under 500 meters which covers the movement of planes on the runway and also the early phase of take off and the last part of landing. Birds and bats, especially flocks can be picked up by ground crew and dispersed but this isn’t the end of the story and an airport must work with the co-operation of its neighbours within a radius of 13km or a total area of 531 square km to further reduce the risks. That’s where things like Warragamba Dam and the Blue Mountains come into play.
How far away from the airport do birds matter?
I was confused by the radius data given. 13km away from the airport sure does seem like a decent enough distance but what height will the planes be then and will that still put the planes in the path of birds? The answers are ‘lower than 5000 ft and yes’ . . .
Flying at 5000 feet or less? You need to be careful! It isn’t like birds can’t fly higher than that though! In November 1975 a commercial Boeing 747 flying above the Ivory Coast in Africa sucked a Rupell’s Griffon Vulture into its engine forcing an emergency landing. The plane was flying at 37,900 feet above sea level at the time, way higher than anyone had ever expected to encounter a bird and reminding us not to take anything for granted.
In general, the higher the altitude, the lower the risk of bird and bat strike based on the likelihood of encountering a bird.
- 6.89% of bird strikes happened at heights above 3500 feet
- 19% happened between 501-3500 ft
- 74% happened between 0-500ft
Birds hit harder the higher they fly!
While it is less likely to cross paths with a feathered friend when flying high it pays to remember that the mass (weight if you like) of a body changes in relation to its speed. The higher the plane is flying the faster the plane is going and therefore the impact with the bird with be more catastrophic as Einstein’s neat equation reminds us.
E = mc2
So one bird at 10,000 feet could rip through an engine with more ferocity than the same bird at 1,000 feet. Worth remembering I think.
So how does all of this relate back to the area surrounding this proposed airport?
Let’s borrow a map from the EIS bird and bat strike section and have a look:
Reference: Bird and Bat Strike.
The green line on the above map shows the boundary of the 13km radius and as you see within that sit a number of bird and bat friendly sites – they are the items named on the diagram. Surprisingly neither the Warragamba dam or the Blue Mountains National Park warrant a special mention on here which is odd given that both areas are well known for their birdlife. Indicative flight paths for this proposed airport were put forward in the EIS but subsequently revoked, as they had revolved around a single merge point for arrivals above the town of Blaxland in the Blue Mountains. Like most people I look at this map and know that the reality is all aircraft moving to and from the west of the airport will have to cross the Blue Mountains and will be doing so at low altitude. The EIS it’s self specified heights of between 4000-6000 ft over the lower mountains, which puts ALL arriving and departing planes into bird strike territory.
Mitigating risks in the 13km zone.
So the airport, should it go ahead will have significant power to influence planning in the 13km zone around it, especially with regards to reducing the potential for bird and bat strike. So the construction of new lakes, the improvement of existing waterways, re-vegetation and beautifying parklands will all have to be done under the provision that they don’t encourage ‘dangerous’ bird or bat behavior. One could easily imagine a situation where ponds are drained to make it easier and grasslands are concreted over. That can’t (or at least shouldn’t) be done to a National Park; especially a World Heritage listed one.
During my reading I’ve realised that it isn’t like the Western Sydney Airport would be the only airport near to either a National Park or bird rich habitat but I did find it is unusual to locate an airport of such planned magnitude next to what is, in effect the airports nemesis – tree and bird wonderland. No matter what anybody says bird and bat strike remains a significant issue for the aviation industry and one that is yet to be resolved.
The Blue Mountains gained world heritage listing for its wide range of eucalypts and large tracts of wilderness so it would be a bit cheeky for an airport to ask us to trim some of those lovely protected trees and kill or scare off some of those equally lovely and rare birds. As for the Warragamba dam well, we all know how much birds love water . . .
Citizen Science Bird Survey of the Area.
Thanks to that bird survey I talked about in the beginning I can get a idea of what birdlife exists in the 13km airport zone by tapping in the data shared by local residents, residents who carried out up to seven 20 minute surveys over that week in October. In fact, it is relatively safe to say that the data contained within this backyard bird survey is of more value than the surveys done for the EIS proper, albeit most of ‘us’ were amateurs! I quickly discovered that the EIS surveying of bat and birdlife in the area was carried out over a few days in March 2015 and actually only consisted of a few drive-through sightings. No night observations (best for bats and flying foxes which do constitute quite a risk for planes), no seasonal variations and quite possibly not enough repeated visitation of sites to build up a statistically relevant picture of events. Hmmm . . .
So is the Low Risk Status of this proposed airport justified?
No, I think not.
Given the busy flight paths from the existing Sydney Airport, logically I can see why the majority of flights will come over the Blue Mountains both to land and to take-off. However, that then puts the majority of flights in danger of bat and bird strike – a danger that has to be managed with one’s hands tied so to speak. These planes will HAVE to pass the mountains at heights of 5000 feet or under – that’s physics not gut feeling or conspiracy theory.
The one semi-positive thing that my research has highlighted to me is that many bird and bat strikes are more of an inconvenience to the humans on board than a threat to human life. That said, I don’t know how positive anyone can feel about flying on a plane that stands a relatively high chance of ‘ingesting’ (that’s what it’s called) bird and bat life, some of which is quite possibly endangered. So I won’t die, but nature might. Nice.
You can just see this as another cost this airport has to plan for and manage while not having complete control. Bird and bat strike will happen, not least because the airport can only control so much and planes need much further than the airports legal boundary before they reach altitudes that put most bird and bat life out of harms way.
There are so many unknown factors with all of this but one thing I am confident in is the need for the Environment Minister, Josh Frydenberg to stipulate that a decision on approval of this airport cannot progress UNTIL we have a much more thorough picture of what is going on in the skies above and around this planned development. The official EIS its self points out the need for more research and I think we owe it to ourselves, the airlines and most importantly the bat and birds of Western Sydney to carry out a more thorough survey over a longer time period. This is especially relevant since we cannot chop down the trees of the National Park and cannot drain the Warragamba Dam and cannot avoid flying at relatively low altitude over the Blue Mountains National Park.
To sum up, I feel less than satisfied with the data that has been used to reach their conclusion and agree with the need for more and wider surveys across a longer time frame. This would allow for a more accurate and honest reflection of the risks and costs both in terms of time delays and asset damage that might be part and parcel of operating out here.
The sad realization for me is that the burden of risk and cost of bird and bat strike sits mainly with the airlines and passengers of the aircraft rather than with the airport operators who can tick their boxes then be done with it to a certain degree. I hope this slightly cynical view wasn’t used to shape the current EIS just to ‘get it done’ so to speak as, if it was we could well be about to witness one of the biggest PR disasters of all time, reality tends to be harder to gloss over than wishful thinking and idealized scenarios.
My final thought is back to Heinrich and his safety triangle. Nobody wants to have their day ruined by a mob of angry birds.
Let’s hope they get back out there with their binoculars and do a proper job of it this time.
(For more information visit www.rawsa.info).