Driving off birds using acft radar

[levm]

Hi Guys, in one of my recent line verification, the TRE told me something I had never heard before (I have been flying for 35 years now !) ...
The statement was: " ... you can use your airborne radar to drive off birds in the vicinity of the airport ... claiming that the birds "feel" the waves and run away ! ".
For me it does not make any sense. I do not know any animal in the earth (including us) that would be able to "feel" electromagnetic (radio) waves. In the other hand, if this statement has a minimum chance to be true it would be written in the radar's manual, I think !.
Thinking a little bit more, at airports we have ATC radars (mainly primary ones), ground radars and meteorological radars and if this would be true the birds would not be a problem at all !
Does anybody heard this before ? Any suggestion is appreciated !

[chris weston]

Do the maths. The ERP from the on board radar is miniscule. Its voodoo.

[Flying Wild]

I recall seeing this written in the airfield info for Faro. It requested pilots to switch on weather radar for arrival and departure as a trial in scaring off birds.

[ShyTorque]

Sorry but that is a myth; trials were run some years ago and as you say birds can't sense radar waves any more than we can.

Birds will react to forward facing white lights, though. The RAF encouraged us to use our landing light/ searchlights when operating at low level.

[Capt Claret]

Douglas/Boeing 717 - radar on entering the runway.; radar off leaving the runway.

The only places I haven't suffered a bird strike are on the apron or a taxiway, where the radar is Off. :hmm:

[Centaurus]

the TRE told me something I had never heard before (I have been flying for 35 years now !)

I first read about that circa 1978 and after that diligently scanned the runway ahead (737-200) prior to departure from Pacific atolls where sea birds concerned us. Had only one bird strike over several years but I always thought it was a dodgy theory. But like believing in God, thought I would cover my arse, "just in case."

Then I happened to read the Collins WXR-700X Pilots guide, (October 1974 edition) and at page 33 it states:

"The average radiated power density of the Collins WXR-700X Weather Radar System is significantly less than the 10mW/cm2 allowable for limiting the exposure of rf energy to humans as noted in FAA Advisory circular, number 20-68B, dated august 1980. The WXR-700X doe not require the use of a dummy load when operated on the ground."

That was in 1974. Presumably the modern radars are safer still?

[Al Murdoch]

I have heard this crap trotted out by very experienced and educated Captains and Instructors alike - I always challenge them to explain how this works. As you might imagine, I have never received a wholly convincing answer.
Even if birds could somehow feel the radar, how would they know where it's coming from and thus get out of the way? Most birds don't seem that clever.

[latetonite]

You take off with the radar anyway. Will not hurt either, or attract the birds.

[de facto]

latetonite You take off with the radar anyway. Will not hurt either, or attract the birds.


I aint when the sky is blue:E

[Bealzebub]

Yes, I am not convinced either, but as Latetonite says "it can't hurt, and even if the birds couldn't care less, it might help someone avoid the CB cloud a little further on. David Attenborough regales us with tales of new scientific and ornithological discoveries that are made every year, as to the previously unknown sensory capabilities of these creatures, so who knows? I am happy to wear odd socks if it is perceived to improve the odds.

[latetonite]

De Facto: you don't have to.
But I aint forget to switch it on when it gets dark either, or when I enter clouds, plus it gives me predictive windshear on my plane, a bit earlier than on yours.

[de facto]

Predictive windshear is separate..you dint need to switch the "WX" on to get it,it activates automatically when the thrust levers are set during take off.

[Lord Spandex Masher]

Doesn't work. Trust me.

[latetonite]

De facto: Right. But with a 12 sec delay. This is for the pilots who forgot the radar..
An airline pilot turns his radar on on TO.

[FullWings]

Interesting one. Now, normally I would agree and say that it's an urban myth but a long time ago in a galaxy far, far away, I worked on ground and airborne radars, civil and military.

One of the guys I was working with claimed he could actually 'hear' radar; well the prf from the transmitter, anyway. We did a few experiments and yes, when close enough, he could detect whether the radar was on or not. He had a theory that there was some sort of rectification going on in his middle ear that was stimulating the nerve endings, giving him the impression of hearing a quiet "chirp". Whatever the true explanation, he did seem fairly unique among us.

So, there *may* be a grain of truth there somewhere. One for Mythbusters?

[The Dominican]

One of the guys I was working with claimed he could actually 'hear' radar; well the prf from the transmitter, anyway. We did a few experiments and yes, when close enough, he could detect whether the radar was on or not. He had a theory that there was some sort of rectification going on in his middle ear that was stimulating the nerve endings, giving him the impression of hearing a quiet "chirp". Whatever the true explanation, he did seem fairly unique among us.

I once knew about a guy that had a pet turtle, he claimed that on occasion that turtle told him to call in sick and that something always happened on those flights.:}

[Bealzebub]

Actually Saxonbloke, I have also seen that on an approach chart somewhere recently, and it wasn't Treviso.

[levm]

Maybe the turtle knows how to avoid birds ... http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gif

[Desert185]

Personally, I think its bunk. Never noticed any difference Stby or On.

[DaveReidUK]

Primary radar doesn't have any effect on birds, but SSR makes them squawk. :*

[Capt Fathom]

Took a bird strike right on the radome once. Caved it in!
The radar was on at the time. Myth Busted!

[FLEXPWR]

Nominal power output on one of the radars on A320 is 125 Watts... over a 30" antenna flat plate, that is about 239 cm2. That is 8 times less powerfull than a home microwave, and 16 times less powerfull than a vaccum cleaner.

I bet I can scare the birds off with the vacuum cleaner on full power with better efficiency than the radar! :}

Now, if we strech the theory reaaaaaally good: many migrating birds have magnetite crystals in parts of their beak or brain, which supposedly helps them navigate. Having an electromagnetic wave pointed directly at them could have a disturbing effect, maybe? But even if that ws the case, would it really make the birds fly away? And in which direction? Maybe they'd come flying straigh towards the source! :E

[Tee Emm]

Old friend of mine was a Typhoon fighter pilot during WW2. He said that when German radar controlled anti-aircraft guns were on to him, the first warning was a clicking or similar noise in his headphones (VHF).

He was leading a formation attacking German forces on D-Day. He heard the noise and immediately changed heading. But for some reason one of the formation pilots in his line astern continued straight ahead and was immediately shot down by remarkably accurate AA fire.

However, in the case of birds and radar the theory was the birds were subject to heat from the weather radar - not "noise."

[AerocatS2A]

Weather radar energy isn't particularly hot. I know a bloke who was leaning against the radome of a jet, chatting to an engineer, after a while his arm got a bit of a tingling feeling. On return to the cockpit he discovered the radar was transmitting! So leaning against the actual radome with it transmitting he got a slight tingling sensation after some time. Any birds far enough away to have not already noticed the big noisy chunk of metal coming their way aren't going to feel a thing from the radar.

[Tee Emm]

but SSR makes them squawk

Correct me if I am wrong (story of my life) but I believe the genesis of transponder codes was during WW2 when they were known as Identification Friend or Foe (IFF for short). In the hope that Germans listening in to RAF frequencies could be fooled, various code names were invented. Thus the code name for IFF was "Parrot." And the code name for transmit was "Squawk."

When RAF controllers wished to tell pilots to switch to a new frequency they would say "Squawk Channel Able

If they told the pilot to switch off his transponder the code word was "Strangle" Thus "Strangle your Parrot"

[latetonite]

Well, at least that's interesting:)

[Tu.114]

I remember that until a while ago LIPZ/VCE charts contained the standing order to keep the weather radar on for takeoff and landing in order to scare the birds away. It has quietly been stricken out of the book though; one assumes that this is due to this methods proven ineffectiveness.

[My names Turkish]

Far better to use a couple of blasts of the ground call siren as you start rolling

[de facto]

De facto: Right. But with a 12 sec delay. This is for the pilots who forgot the radar..
An airline pilot turns his radar on on TO.


Latetonite,please be so kind and give me the reference of this 12secs delay.
I dont switch it on when the sky is clear and i am an airline pilot.:p

[wiggy]

de facto


I suspect latetonight might me alluding to the fact that on some aircraft the Wx radar does indeed fire up, whether you've selected it on or not, at some point v. early in the take-off roll ( on the 777 the radar begins scanning once the thrust levers go into the take-off range)...you don't get weather returns displayed on the ND's if you've left the switch off, but nevertheless the radar is scanning and radiating to provide Predictive Windshear....and on the triple PWS alerts become active 12 seconds after the scanning begins.

That said I don't believe for one moment that the birds dive for cover because of the radar...

[cosmo kramer]

Latetonite,please be so kind and give me the reference of this 12secs delay.
I dont switch it on when the sky is clear and i am an airline pilot.:p

I'll help Latetonite out :E

Alerts are available approximately 12 seconds after the weather radar begins scanning for windshear. Predictive windshear alerts can be enabled prior to takeoff by pushing the EFIS control panel WXR switch

[latetonite]

Thanks Cosmo Kramer.
I usually do not have the memory to know things and quote a valid reference at the same time. But in this case I can refer to Brady's "The B737 Technical Guide".
I trust anybody discussing technical matters about the B737 series has this one in his library.

[de facto]

Sorry by reference i meant the SOURCE.,,where did you get this text from?
You are mentioning the weather radar not the pWS.

From the AMM:

Additional to „normal“ weather radar system, the predictive windshear function provides horizontal windshear warning up to a range of 3 nautical miles.
In the 737 aircraft, this an additional, fully automatic mode of the weather radar system and is not controlled by the pilots.
And from the AMM again:
When the airplane is on the ground and either throttle is moved more than 53 degrees, the PWS comes on automatically.
But in this case I can refer to Brady's "The B737 Technical Guide".
I trust anybody discussing technical matters about the B737 series has this one in his library.


I dont.:E

[latetonite]

Yes, PWS comes on above TLA 53 degrees, same microswitch as your TO Warning, but needs warm up. There is also alternate scanning involved, between use of the radar disc for weather and PWS, and alternate scanning for the Captain and F/O, leading to a possible delay of PWS detection of 12 seconds.

Given a 36 sec average time to rotation, the first third of your take off, when the PWS caution is active, you have thus possibly no indication.

I was kind a weary you do not have those reference books handy.

Nowadays most people I train, get their knowledge from SOP's and answering multiple choice questions. Times have indeed changed.

That does not mean I changed accordingly. I like to keep it simple, and have my WX radar switched on at Line up.
In our company we do not pay for the unavoidable extra fuel burn this habit creates.

[cosmo kramer]

De facto,
The source is your FCOM Chapter 15 Warning Systems.

The weather radar automatically begins scanning for windshear when:
• thrust levers set for takeoff

(....)

Alerts are available approximately 12 seconds after the weather radar begins scanning for windshear. Predictive windshear alerts can be enabled prior to takeoff by pushing the EFIS control panel WXR switch.

And to add to what latetonite already said:

Predictive Windshear Inhibits
During takeoff and landing, new predictive windshear caution alerts are inhibited between 80 knots and 400 feet RA, and new warning alerts between 100 knots and 50 feet RA.

Hence, without turning the WX radar on, you have no predictive windshear alerts for the first 12 seconds, and no predictive windshear alerts after 100 knots.
Basically you are taking off without predictive windshear at all with the radar turned off.

[gums]

I can tellya that the high-power military radars in our fighters( not the weather radar that the heavies have) would fry a bird or human if turned on when the "target" was a few feet away. We also had interference problems with other systems at takeoff, so the 'dar didn't come on until we were rolling or actually WOW.

BTW, there's a new anit-personnel microwave system out there that will cause your skin to itch and maybe boil out at a thousand meters or so. One of the "non-lethal" systems we Yanks seem to be concerned with, heh heh.

Newer systems like the agile scanned phased array dars on the F-22 and F-35 don't have this problem. Yeah, the B-2 and later fighters.

[latetonite]

The FAA has an Advisory Circular regarding distance to stay away from a radar disk. It is the greater distance of 1.) where the radar beam forms away from the antenna and 2.) Where the radiation level reaches 10 mW per square cm.
Honeywell publishes a safe distance of 14 ft away from the center of the disc for their state of the art RDR-4000 series radar, to comply with this circular AC20-68B.
Even in test mode a distance of 3.5 ft is required.

[Gas Bags]

Latonlite,

With no WR selected on there is no time delay....On take off once either throttle goes above 53 degrees the PWS detection is ON. I think you may be confused with the 12 second thing. If WR is not selected on before takeoff then all sweeps of the dish are detecting WS. If WR is selected on before takeoff see below:

Takeoff WR selected on with throttles >53 degrees:

Sweep 1 left to right: Capt WR for the first 3 second period.
Sweep 2 right to left: Both PWS for the next 3 second period.
Sweep 3 left to right: F/O WR for the next 3 second period.
Sweep 4 right to left: Both PWS for the next 3 second period.

And then so on. The most time delay you could have is 3 seconds.

As for the birds..................

[latetonite]

Gas Bags,

Please read the quote from Cosmo Cramer from the FCOM.

Then, Chris Brady mentions 12 sec delay, and blames it to warm up time in his publication.

At the end, if I switch the Wx radar on on line up, I am sure it is available when I push TOGA.

[BARKINGMAD]

Thereby confirming my fears, expressed elsewhere in these fora, about the total and utter tosh being dispensed by those with the title of "trainer"!

Having spent many happy hours on RAF airfields, observing the feathered species cavorting, feeding and possibly breeding within very short distances of those airfields' surveillance and PAR (nodder & wagger) scanners, I would say that the myth seems to live on and we can't get rid of it.

Better to spend your pre-departure taxi phase performing what the engineers describe as a "confidence check", being wary of the quoted 15m radhaz area for humans and the 300 ft hazard area for the aircraft's radar self-damage potential when bounced off other aircraft, bowsers and other vehicles, terminal and other building structures which will reflect damaging signal strength back into the very sensitive receiver circuitry, which is the secret of the performance of modern Wx radars.

Strangely no company even mentions such a check in their SOPs, though the NG MM states that the ordinary weather test, though it fills the screen with pretty colours and blasts off 1 squirt of emf, is not a proper test of the radar's ability to work properly.

Post radar problem rectification, the engineers have to move the 'frame to a suitable position where it can be "fired up" properly to confirm succsessful fixing.

Better to find out before V1 and later, that the "weapon" is not functioning, than to discover the hard way, as some recent hail damage incidents have illustrated?

Maybe a polite request to the relevant "trainer" as to where it is written will provide us all with the Holy Grail of Bird Repellant Radar, meantime remember the turtle story!!

"I dont switch it on when the sky is clear and i am an airline pilot" ????? Highly inadvisable, the sky may be clear on departure, but what about enroute and destination?.

As for that posting referring to a "professional" pilot who believed the weather radar ATTRACTED lightning strikes, now I know there are fairies at the bottom of my garden! :ugh:

[GlueBall]

...so Sullenberger's radar was turned OFF? :uhoh:

[Derfred]

Hands up all those who think they will get a Predictive Windshear alert on a clear day or night...

[Ian W]

Correct me if I am wrong (story of my life) but I believe the genesis of transponder codes was during WW2 when they were known as Identification Friend or Foe (IFF for short). In the hope that Germans listening in to RAF frequencies could be fooled, various code names were invented. Thus the code name for IFF was "Parrot." And the code name for transmit was "Squawk."

When RAF controllers wished to tell pilots to switch to a new frequency they would say "Squawk Channel Able

If they told the pilot to switch off his transponder the code word was "Strangle" Thus "Strangle your Parrot"

Almost right.
Listening to the radar pulse from IFF sounded like a squawk noise and this was the 'colloquial' term used by the engineers. It stuck and has been used since then in R/T to tell an aircraft to switch on its transponder. The wartime R/T that was used to obfuscate what was being talked about was Parrot. The exchange 'Strangle Parrot' -- response 'Polly's Dead' were used. But we are back in the times of 'What's your oranges?' ' Oranges Sweet' :)

[levm]

Hi Guys, thanks all for your opinions but I am not discussing if a PWS works with radar off or the use of the radar for meteo purposes (this is the reason it is there and I am sure all of you know how to use it!). Thanks for the opinions any way!
My post put in discussion whether or not a bird strike could be avoided using your airborne radar !
I think that the big majority of us agree that it is a myth. I could not find any reference about this statement, in a scientific way or a study about this, in spite that few airports briefing charts recommends the use of your radar due to bird concentration.
Thinking a little bit more, if you consider that the radar sweep is like a "knife" (normaly with a gap of 3º ) and very directional transmission (not omnidirectional), the bird should be in your radar beam to be scared off otherwise they would not "feel" or "see" your radar transmission because it does not exist out off the beam.
Getting out of airplanes, I have a small sailboat docked in a fishing port. I was talking to a few fishermen about this and they asked me if it is a joke ! When the fishing net is closed with lots of fish the seagulls are a problem for them and it does not matter if the onboard radar is on or off. (and lets consider their radar is an object sensitive one, much more powerfull than ours, 360º sweep with a large beam with a sweep rate between 1 to 2 revolutions per second (60 to 120 rpm).
Just another point to think about !:hmm:
[LEFT]The discussion is open and I would appreciate any reference to a scientific study about it (if there is one!)

[Ian W]

"Common misconceptions about bird strikes A number of widespread misconceptions about bird strikes may give pilots a false sense of security and prevent them from reacting appropriately to the threat of a bird strike or an actual event. These misconceptions include:


Birds don’t fly at night.
Birds don’t fly in poor visibility, such as in clouds, fog, rain, or snow.
Birds can detect airplane landing lights and weather radar and avoid the airplane.
Airplane colors and jet engine spinner markings help to repel birds.
Birds seek to avoid airplanes because of aerodynamic and engine noise.
Birds dive to avoid an approaching airplane."

This information is from: Strategies for Prevention of Bird-Strike Events


Strategies for Prevention of Bird-Strike Events (http://www.boeing.com/commercial/aeromagazine/articles/2011_q3/4/)

[roulishollandais]

Avoiding them? The Startling Science of a Starling Murmuration - Wired Science (http://www.wired.com/wiredscience/2011/11/starling-flock/)

[bubbers44]

Sullenbergers radar I am sure was turned off because no weather was involved in his Hudson river landing. Why turn it on it you don't need it? Flying into TGU with thousands of turkey buzzard I never turned it on because it doesn't do anything to the birds. See and avoid was the only way to miss them. They didn't see and avoid even though he did one hell of a job of putting it into the Hudson safely. Unfortunately nobody was looking out the window as they approached the geese, probably because of cockpit work load switching frequency, etc.

[Capt Claret]

Sullenbergers radar I am sure was turned off because no weather was involved in his Hudson river landing.

Out if curiosity, what does the A320 FCOM say/recommend re Wx Radar on/off for takeoff to landing?

[BARKINGMAD]

"Unfortunately nobody was looking out the window as they approached the geese, probably because of cockpit work load switching frequency, etc."

So what were they supposed to do upon perceiving the hazard of multiple Canada Geese attacking their craft?

After the RAF lost an aircraft which attempted to "duck under" a flock on the approach, the mantra promulgated at the time was "birds always break down", so don't do it!

The advice in the Strategies attachment referring to not going around seems sound and logical, which is why I and others are seeking information regarding the Nov 2008 737-800 hull write-off at Rome Ciampino but answer came there none from the Italian Investigation, nor from the operating company.

(See thread "Missing Accident Report"). Since moved from Safety to Questions if the Mods would like to explain WHY??!! :confused:

[lomapaseo]

After the RAF lost an aircraft which attempted to "duck under" a flock on the approach, the mantra promulgated at the time was "birds always break down", so don't do it!


Birds do what ever Their flight profile permits to avoid the closing hazard.

Of course their are a myriad of bird hazard strikes by all types of birds but my comments are aimed at the statistical hazard to safe flight (multiple medium-large) birds in a regime where little margin exists for multiple damaging sites to the aircraft.

In spite of the Sullenberger incident the largest threat to flight has been lounging water fowl on or near the runway. When startled these birds go up just high enough to maneuver sideways to clear the threat. Unfortunately the plane also wants to go up after reaching Vr.

Once airborne this type of bird again uses its flight ability to peel off horizontally away from the threat. Considering the closing speed between them there is darn little the pilot can do to avoid the birds. The best course is to leave it up to the birds since their programing in this regard is natural.

If we get into the lesser statistical threats like the Sullenberger incident or the Italian B737 other less common factors are involved.

[Wxgeek]

Avoiding them? The Startling Science of a Starling Murmuration - Wired Science

excellent video:ok:

One predictor of how many birds will be aloft is possibly wind direction. At least in the case of geese in the fall.

We hit 3 snow geese on the approach (180 knots ~2000 agl), 1 in the nose gear, 1-2 in the radome (1 ended up inside the dome) around dusk. Later that evening, after dark and 200 miles away we almost clipped another flock a moment after Vr.

Winds were strong and cold out of the north and I suspect every bird was in the sky to take advantage of the push south.

[latetonite]

Referring to the fishing boat anomaly, if your plane is smelling like fish, you might attract even more than usual, I presume.

[Love_joy]

Interesting thread.

A Captain I used to fly with swore by this, that he'd never had a bird strike in his 40+ years of flying by ALWAYS having th WX radar on whilst low level and for take-off and landing. However, he was still spouting this BS after we'd had a bird strike together.

I've made efforts to test this, with zero success. Whilst waiting for a truck to arrive to scare off a murder (that right isn't it) of crows one morning, I fired up the radar played with the tilt, gain and other various modes. The little sods just sat there and soaks it up.

On another occasion, during a landing we spotted birds passing in front of us. I leaned over and turned it on - the birds actually then turned towards us. So I've seen evidence it actually attracts them!

[rudderrudderrat]

Hi levm,
Should we tell ornithologists that 40 years of using radar to track birds (History - swiss-birdradar (http://www.swiss-birdradar.com/history.html) ) is actually scaring them away and causing them to migrate?

[de facto]

At the end, if I switch the Wx radar on on line up, I am sure it is available when I push TOGA.

If you did a PWS test before hand:E
Next time you fly,let us know the speed you reach 12 secs after the TLA reaches the t/o warning position.
Thanks.

[latetonite]

De facto.

I do not think you contribute anything to this topic.
As a matter of fact, nothing to this forum.

[de facto]

I would like to believe that a few of my posts were useful,but hey i am not here to please you either.:E

[Samba Anaconda]

latetonite

Join Date: May 2001
Location: A few degrees South
Posts: 417
De facto: Right. But with a 12 sec delay. This is for the pilots who forgot the radar..
An airline pilot turns his radar on on TO.


Sigh, some still have " bush " mentality.:hmm:

More problems when bush rats are given new toys with test buttons.;)

[latetonite]

Trying to hide again I see. Well, it is a free world.

[Kalistan]

Give up the fight/argument defacto. Don't sweat the small stuff. There are astute pilots like latetonite who have the wx rdr on for all takeoffs.:ouch:

[de facto]

Apparently but here is my contribution:

Sweep Patterns
The sweep pattern is different in approach and takeoff modes. The system al- ternates between WXR and PWS sweeps.
- PWS and WXR Sweep Pattern in Takeoff Mode ;
Position Dir Radar Sweep Paint Sweep Angle (Degrees) Time
Sweep1 L-R Both WXR data update Both WXR +icons painted -90 to +90 4

Sweep 2 R-L Both PWS data updated Both PWS icons painted +90 to -60 3

Sweep 3 L-R Both PWS data updated Both PWS icons painted -60 to +60 2

Sweep 4 R-L Both PWS data updated Both PWS icons updated +60 to -90 3
- PWS and WXR Sweep Pattern in Approach Mode ;
Position Dir Radar Sweep Paint Sweep Angle (Degrees) Time

Sweep 1 L-R Both WXR data update Both WXR +icons painted -60 to +90 4

Sweep 2 R-L Both PWS data updated Both PWS icons painted +90 to -90 4

Sweep 3 L-R Both PWS data updated Both PWS icons painted -90 to +90 4

Sweep 4 R-L Both PWS data updated Both PWS icons updated +90 to -90 4
- PWS Sweep Pattern ;
Position Dir Radar Sweep Paint Sweep Angle (Degrees) Time

Sweep 1 L-R Both WXR data update Both WXR +icons painted -60 to +60 4

Sweep 2 R-L Both PWSs data updated Both PWS icons painted +60 to -60 3

Sweep 3 L-R Both PWSs data updated Both PWS icons painted -60 to +60 2

Sweep 4 R-L Both PWSs data updated Both PWS icons updated +60 to -60 3
The weather data is updated every fourth sweep.

Every 4 sweeps,meaning 12 secs...
B737-600/700/8007/900 34-43

[latetonite]

Took you a week to organise this cut 'n paste story.
Can you find it also for the Honeywell RDR4000? It's slightly different.

[gkk]

Hi All,

Can anybody tell me whats Damage Chart, or Dent and buckle chart, any help will be appreciated.

[de facto]

Took you a week to organise this cut 'n paste story.
Can you find it also for the Honeywell RDR4000? It's slightly different.


Sorry Latetonite, i also have a life outside of prune:mad:
I wish you well.

[Sop_Monkey]

Someone asked a few pages back, hands up if radar can predict CAT. My hand is down.

Just because we don't understand something doesn't mean it don't work for one reason or another. Someone mentioned birds were stupid. Really? Then how the :mad: can they navigate over thousands of miles and find their way home. Pigeons and migrating species. We humans are the turkeys.

If someone explains and proves how birds navigate, then and only then, when they tell me radar don't repel birds I will believe them. Until then I have an open mind.

[TeachMe]

Well, somebody above asked for 'facts' so did a bit of searching of bio journals. Basically found little relevant information, suggesting that it has not been well studied. However the article below does have two interesting points.

1) they found no evidence of radar on birds
2) they note that others have found evidence

Behaviour of migrating birds exposed to X-band radar and a bright light beam (http://jeb.biologists.org/content/202/9/1015.short)

I read the article and has some good references to follow up if anyone is interested.

So, it seems an open question still.

Some thoughts:

1) power is not an issue - a battery powered laser can do more eye damage than a 60 watt bulb
2) it may have something to do with the bird species and radar frequency mix
3) nothing is ever absolute - single cases are basically irrelevant to making a broad conclusion

I suspect some birds may be able to sense it in some situations, it is just that we o not know what ones in what situations, nor do we know what behavior such a sensation would induce.

About the people who could sense it, this seems reasonable and reminds me of how some people can sense polarized light even though most can not. (e.g. Haidinger's brush - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Haidinger%27s_brush))

[Canuckbirdstrike]

May I suggest going to the Transport Canada website Transport Canada / Transports Canada (http://www.tc.gc.ca) and look for the book Sharing the Skies. You can download the PDF files and read them. The book clearly states that based on numerous inquiries with leading biologists in the field of bird strikes, along with research of peer reviewed papers that ther is NO evidence that aircraft radar is detected or understood as a threat by birds.

This remains one of the biggest urban myths in aviation along with the thoughts that birds cannot be effectively managed for substantial risk reduction.

I suggest reading the book will give you a better understanding of the problem and what can be done.

[bubbers44]

Over 600 approaches and departures from Tegucigalpa Honduras never turned the radar on with thousands of turkey buzzards in the valley. We always visually avoided them with no problem. Radar does nothing. Visually you can avoid them if you look far enough ahead. If you see them at the last few seconds you probably can't avoid them. We had no problem just looking out the window and maneuvering around them when they were dots, not right in front of you. It worked fine for us but I know some pilots will say you can not avoid a bird strike. You have to look way ahead of your flight path and it is quite easy.

[bubbers44]

Sully could have prevented his Hudson River landing if they had seen the birds.

[billabongbill]

He wasn't astute enough. They could have prevented that heroic saga had he dodged the birdies like you did over Toncontin!

[Al Murdoch]

Really? Then how the can they navigate over thousands of miles and find their way home
I can't lay an egg either - proves nothing. Humans are quite capable of navigating long distance and have done so for millenia.
Unless you can show me that birds have some sort of directional sensing facility (like an eye, but for radar) that will tell them from where the threat direction is coming, so they can indeed avoid the aircraft, I think it is highly improbable that radar has any effect whatsoever. What I'm trying to say is, it's bollocks. Turn on your radar on the ground - see what the birds do? Oh yeah, nothing.

[bcgallacher]

Gkk -
A damage chart shows all the existing minor dents and dings that an individual aircraft suffers during its time in service. These areas of minor damage will have been assessed and noted by maintenance so that a record can be kept.
I have also seen such damage marked on the aircraft itself.