jet/bird evasive action
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Airbus Birdstrike Info and Approach Policy
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http://www.airbus.com/.../AirbusSafe..._ENV-SEQ05.pdf
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Airbus Flight Operations briefing notes Operating Environment Bird Strike Threat Awareness
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http://www.airbus.com/.../AirbusSafe..._ENV-SEQ05.pdf
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Airbus Flight Operations briefing notes Operating Environment Bird Strike Threat Awareness
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In my considered opinion, large excursions of the flight path of a faster moving jet airliner, to avoid potential bird impacts, is highly unlikely to be met with favorable results.
IE: the pilots can't see 'em in time, and the maneuvering to avoid is chancy, at best, dangerous quite possibly.
So...forgetaboutit.
Usually, the 'maneuver to avoid' scenario is dreamed up by some MSFS amateur, and not a real-world airline pilot, with considerable flying experience in his/her profession.
IE: the pilots can't see 'em in time, and the maneuvering to avoid is chancy, at best, dangerous quite possibly.
So...forgetaboutit.
Usually, the 'maneuver to avoid' scenario is dreamed up by some MSFS amateur, and not a real-world airline pilot, with considerable flying experience in his/her profession.
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i'm not an msfs guy
i'm trying to figure a way to avoid bird ingestion in the following scenario
see birds with time to act
unable to climb because of energy or traffic or other considerations
and a way of getting the engines out of the bird formation...at least one of the engines anyway.
I seem to recall (correct me please) that someone on sully's flight commented on what a nice formation the birds were in.
if you have time for a comment...there MIGHT be time for a well considered maneuver.
i'm trying to figure a way to avoid bird ingestion in the following scenario
see birds with time to act
unable to climb because of energy or traffic or other considerations
and a way of getting the engines out of the bird formation...at least one of the engines anyway.
I seem to recall (correct me please) that someone on sully's flight commented on what a nice formation the birds were in.
if you have time for a comment...there MIGHT be time for a well considered maneuver.
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i'm not an msfs guy
i'm trying to figure a way to avoid bird ingestion in the following scenario
see birds with time to act
unable to climb because of energy or traffic or other considerations
and a way of getting the engines out of the bird formation...at least one of the engines anyway.
I seem to recall (correct me please) that someone on sully's flight commented on what a nice formation the birds were in.
if you have time for a comment...there MIGHT be time for a well considered maneuver.
i'm trying to figure a way to avoid bird ingestion in the following scenario
see birds with time to act
unable to climb because of energy or traffic or other considerations
and a way of getting the engines out of the bird formation...at least one of the engines anyway.
I seem to recall (correct me please) that someone on sully's flight commented on what a nice formation the birds were in.
if you have time for a comment...there MIGHT be time for a well considered maneuver.
Aural warning?
K_9, I agree with your arguments.
Does anyone happen to know if Sullenberger's birds were opposite-direction, same-direction, or "crossing traffic"? In my Istanbul approach case (see above) we caught the Storks up from behind, so they may have been unaware of our presence until they heard our engines (too late).
I'm wondering if there is any evidence that bird formations will peel off to avoid a conspicuous, giant bird coming at them. They may not be as stupid as we assume. Either way, we are so quiet and fast that they may not see or hear us in time if we are coming from behind.
This may sound frivolous, but has any research been done into the possibility of some kind of aural warning from aircraft? What is the current state of play on aural bird-scaring at airfields, and could similar technology be used from the air? This would depend on the crew being aware of the confliction, of course, so would only work in a minority of cases. We wouldn't be very popular if all the quiet-engine technology was wasted by a constant, fog-horn-like racket on all departures and arrivals... That being the case, is there any type of short-range radar or infra-red device that can detect birds, and issue a warning to the crew? Perhaps Canuckbirdstrike can answer some of the above.
Does anyone happen to know if Sullenberger's birds were opposite-direction, same-direction, or "crossing traffic"? In my Istanbul approach case (see above) we caught the Storks up from behind, so they may have been unaware of our presence until they heard our engines (too late).
I'm wondering if there is any evidence that bird formations will peel off to avoid a conspicuous, giant bird coming at them. They may not be as stupid as we assume. Either way, we are so quiet and fast that they may not see or hear us in time if we are coming from behind.
This may sound frivolous, but has any research been done into the possibility of some kind of aural warning from aircraft? What is the current state of play on aural bird-scaring at airfields, and could similar technology be used from the air? This would depend on the crew being aware of the confliction, of course, so would only work in a minority of cases. We wouldn't be very popular if all the quiet-engine technology was wasted by a constant, fog-horn-like racket on all departures and arrivals... That being the case, is there any type of short-range radar or infra-red device that can detect birds, and issue a warning to the crew? Perhaps Canuckbirdstrike can answer some of the above.
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Going off my previous comments on this subject, and in agreement with what 411a said, in a jet you're not gonna see them in time to do anything about it, like I said, I've seen people try, didn't make a difference (maybe they would've even missed if nobody tried rolling the plane a bit), I once tried to avoid a flock in a 1900, but we were only doing 120 knots at the time so I just pitched down a bit and flew under them, did the same doing about 100 knots in a 207 at 2000 feet off a cliffside where they like to nest. I think that, realistically, there is a speed limit as to where you can see one in time and do something useful about it, needless to say, 99/100 jet aircraft are going beyond that speed limit.
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Gents,
You can see the birds in time, in my opinion, if you are looking for them in the right spot. Admitted, I'm a tactical jet aviator, not a big iron one, but if I can get my aircraft AND my wingman's aircraft over a cluster of buzzards while flying in towards the airfield at 250+ knots, you can get your big iron bird over the top too. Perhaps when everything is down and dirty, we both don't have a lot of options, but the key is acting positively and early.
As I mentioned early in this thread, the spot that you have to scan for birds is small and is directly ahead of your aircraft. You have to continually be giving this spot the close eye in bird country. You should take the effort to get your glasses prescription tweaked to better than 20/20. The big birds can usually be seen in time unless they are flying IFR or at night. Hitting the smaller, less visible birds, has fewer consequences, normally just need to clean the red streak off the airframe.
You can see the birds in time, in my opinion, if you are looking for them in the right spot. Admitted, I'm a tactical jet aviator, not a big iron one, but if I can get my aircraft AND my wingman's aircraft over a cluster of buzzards while flying in towards the airfield at 250+ knots, you can get your big iron bird over the top too. Perhaps when everything is down and dirty, we both don't have a lot of options, but the key is acting positively and early.
As I mentioned early in this thread, the spot that you have to scan for birds is small and is directly ahead of your aircraft. You have to continually be giving this spot the close eye in bird country. You should take the effort to get your glasses prescription tweaked to better than 20/20. The big birds can usually be seen in time unless they are flying IFR or at night. Hitting the smaller, less visible birds, has fewer consequences, normally just need to clean the red streak off the airframe.
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The challenge with any system to warn and deter birds is habituation. If you use noise or other harassing techniques eventually the birds learn or habituate to the fact that this noise is not a threat, just a nuisance. Much like the "snake oil" salesmen of the previous century there are many manufacturer's with wild claims on various sound based systems deterring birds. There is no data from reputable scientific studies to back these claims.
To illustrate how clever birds are at figuring this out. I sat one day in the line up for takeoff at a major airport that used propane cannons that automatically rotated and fired to scare birds. I watched a seagull sitting on the end of the cannon riding back and forth as it moved. Then it would fly off, let the cannon activate and then fly back to his perch and enjoy the view and look for food. I took the time to visit with the wildlife control personnel at this airport and watch the event up close. The bird was smart enough to hear the propane valve open to let the fuel into the chamber and realize that is what triggered the noise. He just learned to work the system.
Deterring birds at airports is hard work. It is guerrilla warfare and you have to constantly outsmart your enemy and change tactics. The problem is that in our instant, virtual world everyone wants a one stop automatic solution. For birds and wildlife there is not one.
So putting noise makers on aircraft will not work. First from the wildlife perspective and secondly for the fact that with aircraft speeds the sound will not reach the birds in sufficient time.
Encounters with birds above 1,000 ft AGL are not within the area where ground based strategies will work in general. In some cases if you can remove an attractant (food or shelter) then the flight path may get modified, but this is a long term and challenging activity. At altitude detection and avoidance is the strategy. Significant work has been and continues to be done with avian radar system that have species detection and bird flight path prediction capabilities. The technology is being used in trials at some airports, but it is expensive and to date no one has bothered to consult with the aviation industry in a meaningful way on how we would use this technology in practice.
To illustrate how clever birds are at figuring this out. I sat one day in the line up for takeoff at a major airport that used propane cannons that automatically rotated and fired to scare birds. I watched a seagull sitting on the end of the cannon riding back and forth as it moved. Then it would fly off, let the cannon activate and then fly back to his perch and enjoy the view and look for food. I took the time to visit with the wildlife control personnel at this airport and watch the event up close. The bird was smart enough to hear the propane valve open to let the fuel into the chamber and realize that is what triggered the noise. He just learned to work the system.
Deterring birds at airports is hard work. It is guerrilla warfare and you have to constantly outsmart your enemy and change tactics. The problem is that in our instant, virtual world everyone wants a one stop automatic solution. For birds and wildlife there is not one.
So putting noise makers on aircraft will not work. First from the wildlife perspective and secondly for the fact that with aircraft speeds the sound will not reach the birds in sufficient time.
Encounters with birds above 1,000 ft AGL are not within the area where ground based strategies will work in general. In some cases if you can remove an attractant (food or shelter) then the flight path may get modified, but this is a long term and challenging activity. At altitude detection and avoidance is the strategy. Significant work has been and continues to be done with avian radar system that have species detection and bird flight path prediction capabilities. The technology is being used in trials at some airports, but it is expensive and to date no one has bothered to consult with the aviation industry in a meaningful way on how we would use this technology in practice.
Thanks Canuckbirdstrike, for your insights.
Quote:
If you use noise or other harassing techniques eventually the birds learn or habituate to the fact that this noise is not a threat, just a nuisance.
I was looking at the problem from a different angle: that of INFORMING the birds of our presence, i.e., an attention-getter; not trying to TRICK them by, for example, mimicking the sound of a raptor. My idea does not itself involve any attempt to curtail bird activity on airfields, which is evidently futile.
You have illustrated the intelligence and learning capabilities of birds. Is there any evidence that they will continue on course deliberately towards what presumably resembles a large, strange bird?
You argue that, with aircraft speeds, the sound would not reach the birds in sufficient time. If crews are to continue relying on Mk1 eyeball, time is definitely of the essence. In clear-visibility daylight, a small flight of medium-to-large birds might be visible at about a mile or so? In my Istanbul case, I distinctly remember having time to weigh up the options. With our lights all on, experience suggested they would peel off in good time. But – probably because we caught them up from behind and they didn't see us – they left it very late. My guess is that the first they knew of us was our all-too-modest engine noise.
A bird-detection system like airborne avian radar might work in any visibility, and detect at several miles. At a range of 3nm, the attention-getting sound would take just over 15 seconds to carry; at 180 kts, the aircraft would arrive about 45 seconds later.
I presume any suitable speaker/megaphone would create drag and be vulnerable at high IAS, so perhaps it could extend and retract with the landing lights.
Quote:
If you use noise or other harassing techniques eventually the birds learn or habituate to the fact that this noise is not a threat, just a nuisance.
I was looking at the problem from a different angle: that of INFORMING the birds of our presence, i.e., an attention-getter; not trying to TRICK them by, for example, mimicking the sound of a raptor. My idea does not itself involve any attempt to curtail bird activity on airfields, which is evidently futile.
You have illustrated the intelligence and learning capabilities of birds. Is there any evidence that they will continue on course deliberately towards what presumably resembles a large, strange bird?
You argue that, with aircraft speeds, the sound would not reach the birds in sufficient time. If crews are to continue relying on Mk1 eyeball, time is definitely of the essence. In clear-visibility daylight, a small flight of medium-to-large birds might be visible at about a mile or so? In my Istanbul case, I distinctly remember having time to weigh up the options. With our lights all on, experience suggested they would peel off in good time. But – probably because we caught them up from behind and they didn't see us – they left it very late. My guess is that the first they knew of us was our all-too-modest engine noise.
A bird-detection system like airborne avian radar might work in any visibility, and detect at several miles. At a range of 3nm, the attention-getting sound would take just over 15 seconds to carry; at 180 kts, the aircraft would arrive about 45 seconds later.
I presume any suitable speaker/megaphone would create drag and be vulnerable at high IAS, so perhaps it could extend and retract with the landing lights.
A bird-detection system like airborne avian radar might work in any visibility, and detect at several miles. At a range of 3nm, the attention-getting sound would take just over 15 seconds to carry; at 180 kts, the aircraft would arrive about 45 seconds later.
!!!!! Think SATURN 5 lift-off kind of volume.(Sound drops 6dB with every doubling of distance)
That is seriously loud!
And remember sound drop-off with distance is also frequency dependent, so if your intent was a high frequency laden sound, then it would have to start off even louder.
Any speaker used is going to struggle also with the effect of airspeed impeding it's ability to function in the first place - you'd have to use some kind of compression driver, which by nature need to be horn-coupled to achieve reasonable volume - sticking a biggish horn (one able to generate 140+dB) is not going to do the aerodynamics much good, let alone what your passengers might think.
- GY
Last edited by john_tullamarine; 7th Mar 2011 at 03:23.
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The key with bird sensing and responses is linking what they sense to a threat. If not threatened the birds will not react.
Birds are not inherently programmed to perceive an aircraft as a threat.
Reprogramming bird behaviour on a global basis is not particularly possible.
Birds are not inherently programmed to perceive an aircraft as a threat.
Reprogramming bird behaviour on a global basis is not particularly possible.
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60 degrees of bank in an airliner is a NO NO for many reasons... approach speed, passengers, low aileron roll rate at that speed.. come on... just have all your lights on and apply some airmanship given the info on birds that atc have given you or that you can see... or whatever.. there is no checklist for this situation
Garage Years,
Thanks for your comments. I have to admit to being ignorant on sound propagation and energy levels. I understand your point that, if an observer doubles his distance from the source, the perceived sound energy will be a quarter (-6dB), but can't get my head around what happens very near the source. By the way, I had in mind a very directional one, if possible, using some kind of megaphone. The sound would be concentrated as much as possible into a flattened cone about 30 deg wide, and 10 deg vertical. Would that help?
Canuckbirdstrike,
Thanks for expressing the problems so clearly and succinctly! Bird psychology is also beyond my ken. So is your answer to my question: "Is there any evidence that they will continue on course deliberately towards what presumably resembles a large, strange bird?" a definite "YES"?
If not, here's another: on hearing a loud, unfamiliar sound, do birds turn their heads and look for the possibility of danger?
Chris
Thanks for your comments. I have to admit to being ignorant on sound propagation and energy levels. I understand your point that, if an observer doubles his distance from the source, the perceived sound energy will be a quarter (-6dB), but can't get my head around what happens very near the source. By the way, I had in mind a very directional one, if possible, using some kind of megaphone. The sound would be concentrated as much as possible into a flattened cone about 30 deg wide, and 10 deg vertical. Would that help?
Canuckbirdstrike,
Thanks for expressing the problems so clearly and succinctly! Bird psychology is also beyond my ken. So is your answer to my question: "Is there any evidence that they will continue on course deliberately towards what presumably resembles a large, strange bird?" a definite "YES"?
If not, here's another: on hearing a loud, unfamiliar sound, do birds turn their heads and look for the possibility of danger?
Chris
By the way, I had in mind a very directional one, if possible, using some kind of megaphone. The sound would be concentrated as much as possible into a flattened cone about 30 deg wide, and 10 deg vertical. Would that help?
(I am ignoring some aspects of frequency here - higher frequencies tend to travel in what I like to think of as straight lines, whereas low frequencies "bend" much more easily)
Cheers, GY
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Chris, simple question complex answer. Different birds have different reactions to stimulus, sound, sight or smell. The answer is further complicated by whether it is a solitary bird or a flocking bird.
As for birds perceiving aircraft as large strange birds, the jury is out on this, We cannot get inside a birds brain and really determine what they think an aircraft is. Further, no detailed studies have been done on this and of course each species would have to be individually researched.
I know I have not answered your question because you are looking for a "one size fits all" answer and in the world of birds and mammals that does not happen.
As for birds perceiving aircraft as large strange birds, the jury is out on this, We cannot get inside a birds brain and really determine what they think an aircraft is. Further, no detailed studies have been done on this and of course each species would have to be individually researched.
I know I have not answered your question because you are looking for a "one size fits all" answer and in the world of birds and mammals that does not happen.
I've seen quite a lot of bird nearmisses, as a tower controller, and quite a few strikes. (And in one case a bird death apparently resulting from a loss of control/ground impact after a wake turbulence encounter. Oyster catcher vs B732.)
Different species of bird definitely exhibit different behaviour when an airliner is about to share their airspace, ranging from apparent oblivion, through random scattering, to an intelligent appearing and timely avoiding manoeuver. That last is rare. Usually the bird avoiding action, once it has perceived the aeroplane, occurs as or after the aeroplane passes.
I haven't particularly noticed if flocking makes a difference, although it appears that some birds flock together in a cohesive avoiding action (Starlings and pigeons, for example), others randomly scatter and others seem to become agitated, yet seem stoically to refuse (or unable) to break formation, like Canadian geese.
This would make an interesting study, for sure. (Is anyone doing it?)
I know from experience (mentioned several posts back) that some types of birds will immediately turn, together, if the aircraft heading toward them starts a turn the other way. It doesn't need to be a 60 degree bank. They start turning as soon as they register the bank...maybe 5 degrees, if that. And in one story above, concerning the Buzzard, the bird turned with the aircraft. Twice. (The dumbass.)
Different species of bird definitely exhibit different behaviour when an airliner is about to share their airspace, ranging from apparent oblivion, through random scattering, to an intelligent appearing and timely avoiding manoeuver. That last is rare. Usually the bird avoiding action, once it has perceived the aeroplane, occurs as or after the aeroplane passes.
I haven't particularly noticed if flocking makes a difference, although it appears that some birds flock together in a cohesive avoiding action (Starlings and pigeons, for example), others randomly scatter and others seem to become agitated, yet seem stoically to refuse (or unable) to break formation, like Canadian geese.
This would make an interesting study, for sure. (Is anyone doing it?)
I know from experience (mentioned several posts back) that some types of birds will immediately turn, together, if the aircraft heading toward them starts a turn the other way. It doesn't need to be a 60 degree bank. They start turning as soon as they register the bank...maybe 5 degrees, if that. And in one story above, concerning the Buzzard, the bird turned with the aircraft. Twice. (The dumbass.)
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The one time mentioned above was a large hawk crossing final in front of me, left to right. We eyeballed each other. He wasn't going to give way. I did. He just carried on, victorious.
if you are head on with a formation of birds, bank YOUR plane about 60 degrees
Fly through the buggers and hope for the best (for their sake, I always feel bad killing a fellow aviator
).We been flying jets commercially for 60 years and the one Hudson incident, the statistical evidence doesn't warrant any of the risk suggested here.
Keep the speed down if there are many birds and put the lights on, are the only valid suggestions in this thread. Most of the time where you are actually able to see them is on final when the speed is low. Maneuvering to avoid would be absolutely prohibited, only option would be a go-around. Even this may be a bad idea, unless you are absolutely sure that it will avoid them (let say that you see a flock of 1000 birds sitting on the threshold when you are still at 500 feet). Going around when it's too late (birds already in the air in front of the windows), may only increase the risk since the engines will be at a higher RPM with a much bigger likelihood of severe damage.
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Lots of good discussion here and as always an evolving thread.
The perception that statistically this is not a risk is a flawed argument for two reason; first the data just does not support the assertion and second risk needs to be assessed using the matrix or exposure probability and severity and the use of data to solely assess risk is a flawed methodology.
There also needs to be an understanding of the aircraft certification requirements for bird strikes; engine and airframe. If we confine the discussion to airline category, jet powered aircraft, which have the highest requirements, there are deficiencies in the requirements that are no starting to be discussed.
One of the key deficiencies is the lack of a requirement to consider damage to more than one engine.
The next is that there is no requirement to consider damage to the aircraft AND the engine(s) at the same time.
Accident and incident reports are clearly showing that this is occurring and at a rate that is worthy of design consideration.
I have read many reports of aircraft being damaged after a bird encounter with an engine and aircraft systems such as hydraulic and flight controls damaged at the same time. With a few exceptions the aircraft have been recovered without injury or death.
My point is that as pilots we do need to learn more about this risk.
Take the time read "Sharing the Skies" it has all the salient facts about certification standards and it provides good information on risk mitigation strategies.
It is available on line at the link I provided earlier on in this thread.
A lot of meticulous research went into this book and the material is accurate and verified. I can attest to this personally. I wrote five of the chapters and acted as the technical editor and we were required to validate everything.
No I do not get royalties for the book.....
There is also lots of other material available out there at the various national and international bird strike committees websites.
The perception that statistically this is not a risk is a flawed argument for two reason; first the data just does not support the assertion and second risk needs to be assessed using the matrix or exposure probability and severity and the use of data to solely assess risk is a flawed methodology.
There also needs to be an understanding of the aircraft certification requirements for bird strikes; engine and airframe. If we confine the discussion to airline category, jet powered aircraft, which have the highest requirements, there are deficiencies in the requirements that are no starting to be discussed.
One of the key deficiencies is the lack of a requirement to consider damage to more than one engine.
The next is that there is no requirement to consider damage to the aircraft AND the engine(s) at the same time.
Accident and incident reports are clearly showing that this is occurring and at a rate that is worthy of design consideration.
I have read many reports of aircraft being damaged after a bird encounter with an engine and aircraft systems such as hydraulic and flight controls damaged at the same time. With a few exceptions the aircraft have been recovered without injury or death.
My point is that as pilots we do need to learn more about this risk.
Take the time read "Sharing the Skies" it has all the salient facts about certification standards and it provides good information on risk mitigation strategies.
It is available on line at the link I provided earlier on in this thread.
A lot of meticulous research went into this book and the material is accurate and verified. I can attest to this personally. I wrote five of the chapters and acted as the technical editor and we were required to validate everything.
No I do not get royalties for the book.....
There is also lots of other material available out there at the various national and international bird strike committees websites.