About time somebody asked this...
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About time somebody asked this...
I have recently gained my PPL(G) - Gyrocopters.
Whilst being instructed and subsequently flying around the Kirkbride area i have had (as many other gyro pilots have had) our share of close encounters with fast jets.
Whilst its exhilerating for us when they fly underneath us at less than 800ft
CAN YOU ALWAYS SEE US electronically? 
Whilst being instructed and subsequently flying around the Kirkbride area i have had (as many other gyro pilots have had) our share of close encounters with fast jets.
Whilst its exhilerating for us when they fly underneath us at less than 800ft
CAN YOU ALWAYS SEE US electronically?
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Whilst flying a similar type of (Wallis) aircraft over Norfolk in the early '80's , I came fairly close to e.g. Jags out of Colt on occasion (actually they came fairly close to me ) enough to mutually wave at times. I have no doubt that they could usually see me as well from way out when I was on or above their horizon . Below it didn't really matter.
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See and Avoid
Actually a very good question. There was some research done by the then DERA CHS at Farnborough which showed that, in a typical fast jet, the human eye/brain is not sufficient to scan a large enough area in time to take the necessary action to avoid collisions.
A lot of pilots will, like Tourist above, just come out with the mantra "see and avoid", but this is pretty pointless if you don't see the threat!
The study resulted in the widespread fitting of High Intensity Strobe lights to military aircraft, as well as some other interesting recommendations which were not taken up, like light ac and helicopters flying the opposite way through flow arrows - the idea being that they then have the threat in front of them (and are therefore more likely to see it) rather than being hit by a jet from behind - howwever the equation is a delicate balance because while you have twice (or three times) as many pairs of eyes looking, you also have less time because the velocities sum rather than subtract.
A lot of pilots will, like Tourist above, just come out with the mantra "see and avoid", but this is pretty pointless if you don't see the threat!
The study resulted in the widespread fitting of High Intensity Strobe lights to military aircraft, as well as some other interesting recommendations which were not taken up, like light ac and helicopters flying the opposite way through flow arrows - the idea being that they then have the threat in front of them (and are therefore more likely to see it) rather than being hit by a jet from behind - howwever the equation is a delicate balance because while you have twice (or three times) as many pairs of eyes looking, you also have less time because the velocities sum rather than subtract.
“The study resulted in the widespread fitting of High Intensity Strobe lights to military aircraft….”
Which brought their own problems, when fitted incorrectly…..
http://www.mod.uk/DefenceInternet/Ab...elicopters.htm
See para 141. “Unfit for Purpose”. Pity this wasn’t declared before the accident and the kit removed. Oh, wait a minute, it was.
I recall trials 21 years ago on a laser-besad collision avoidance system developed by RSRE/DRA (whatever they were at the time). In a Tornado I think. The aim was to give warning on the HUD of power cables and similar. RAF asked that a solution be developed to a given spec (xx diameter cable @ yy range), and RSRE replied “we can already better that”. Was it ever fitted?
Which brought their own problems, when fitted incorrectly…..
http://www.mod.uk/DefenceInternet/Ab...elicopters.htm
See para 141. “Unfit for Purpose”. Pity this wasn’t declared before the accident and the kit removed. Oh, wait a minute, it was.
I recall trials 21 years ago on a laser-besad collision avoidance system developed by RSRE/DRA (whatever they were at the time). In a Tornado I think. The aim was to give warning on the HUD of power cables and similar. RAF asked that a solution be developed to a given spec (xx diameter cable @ yy range), and RSRE replied “we can already better that”. Was it ever fitted?
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exhilerating for us when they fly underneath us at less than 800ft
? It's legal and it's necessary for mil pilots in order to do this in order to be able to carry out our jobs. I suggest if you're that worried about it that you stay well above the jets. After all, you're flying for fun, not in order to carry out your job.
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Thanks for the contributions
Thanks for the contributions so far, but no-one has answered my question.
In cross section a modern gyro pod is about 4 ft wide x 8 ft long, rotors 25ft dia.
So, can military jets see us on their radars' or not?
In cross section a modern gyro pod is about 4 ft wide x 8 ft long, rotors 25ft dia.
So, can military jets see us on their radars' or not?
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To be frank, I don't think they'll be looking for you. A Radar isn't a magic torch which will see anything and everything. Furthermore, the radar isn't used for detection of other aircraft at low level (as far as I know...AD notwithstanding!). The radar is used for TFR (a scanning monopulse), fixing the kit and terrain avoidance (GMR). Whilst there might be some radar reflection from your rotors or pod, it is likely that the bright up they produce will be lost in the ground return or gained-out at high gain settings.
The big sky principle works. If all else fails, see and avoid.
Blunty
The big sky principle works. If all else fails, see and avoid.
Blunty
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The issue of TCAS is an ongoing one - notably, the Tucano fleet at Linton On Ouse is presently being retrofitted with TCAS as a trial to gauge it's utility. The Vale of York is especially busy so offers an opportunity to evaluate it's use in a fairly high traffic density environment.
Having flown in both pre-mod and post-mod Tuc's, in my opinion the TCAS is a nice-to-have but not an essential. I found that in most cases, the traffic information it gave me occured after I had visually spotted the aircraft in question (we used it set to give an audible warning within a reasonably short range). So, as a lifesaver it could be useful but it didn't - and shouldn't - replace an effective lookout scan. Furthermore, in a high traffic density area, it was a distraction.
There is an argument for fitting TCAS to military aircraft, and as Mode S becomes more commonplace, the system should help to spot gliders, microlights etc which would previously have not been squawking. However, there are other issues, some of which you have touched on, such as weight and space. Also, there are certification issues, integration issues, emcon issues etc. Not to mention the cost! Weigh these against the utility, and the fact that the aircraft are designed to be used in war and not optimised for the UK, leads me to suggest that the advantage gained from TCAS may not be as great as you may imagine.
The original question related to the probability of a low flying military aircraft detecting a gyrocopter by electronic means. In my opinion (and I stand to be corrected) this is unlikely. A ground mapping radar is not optimised for detection of airbourne targets, and unlikely to be used for that purpose. TFR - forget it! There is no TCAS system in FJ aircraft yet. Do gyrocopters squawk? It is possible that the IR signature may be picked up on the FLIR, but I could not say how likely this would be.
However, as many of my more learned corespodents have suggested, the see and avoid principle works well when used correctly, and every effort is taken to avoid hitting a gyrocopter, hang glider or any other air user. I would suggest that, whilst every effort should be made to reduce them, collisions between air users should be viewed as a tragic but natural risk of the flying we all do in the restriced airspace available to us.
Blunty
Having flown in both pre-mod and post-mod Tuc's, in my opinion the TCAS is a nice-to-have but not an essential. I found that in most cases, the traffic information it gave me occured after I had visually spotted the aircraft in question (we used it set to give an audible warning within a reasonably short range). So, as a lifesaver it could be useful but it didn't - and shouldn't - replace an effective lookout scan. Furthermore, in a high traffic density area, it was a distraction.
There is an argument for fitting TCAS to military aircraft, and as Mode S becomes more commonplace, the system should help to spot gliders, microlights etc which would previously have not been squawking. However, there are other issues, some of which you have touched on, such as weight and space. Also, there are certification issues, integration issues, emcon issues etc. Not to mention the cost! Weigh these against the utility, and the fact that the aircraft are designed to be used in war and not optimised for the UK, leads me to suggest that the advantage gained from TCAS may not be as great as you may imagine.
The original question related to the probability of a low flying military aircraft detecting a gyrocopter by electronic means. In my opinion (and I stand to be corrected) this is unlikely. A ground mapping radar is not optimised for detection of airbourne targets, and unlikely to be used for that purpose. TFR - forget it! There is no TCAS system in FJ aircraft yet. Do gyrocopters squawk? It is possible that the IR signature may be picked up on the FLIR, but I could not say how likely this would be.
However, as many of my more learned corespodents have suggested, the see and avoid principle works well when used correctly, and every effort is taken to avoid hitting a gyrocopter, hang glider or any other air user. I would suggest that, whilst every effort should be made to reduce them, collisions between air users should be viewed as a tragic but natural risk of the flying we all do in the restriced airspace available to us.
Blunty
The issue of TCAS is an ongoing one - notably, the Tucano fleet at Linton On Ouse is presently being retrofitted with TCAS as a trial to gauge it's utility. The Vale of York is especially busy so offers an opportunity to evaluate it's use in a fairly high traffic density environment.
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RCS, eh?
Is 1 sq m partictuarly large, small or indifferent? How does that compare to the average values for a Torndao or F15, for example? What is the minimum RCS you could expect an air intercept radar to detect at normal operating frequencies? What about a ground mapping radar? Your reply needs more information to be complete (well, for those of us who don't know these things anyway!).
I did a google to try to answer the above myself, but couldn't find anything. However, I did learn:
(from Wikipedia)
Every day is a school day!
Blunty
Edit: Further research suggests that the typical RCS values for a fighter type ac range between 1 and 50 square metres. The main variables are aspect, and frequency. This information taken from the very useful http://www.aerospaceweb.org/question...cs/q0168.shtml , if you're interested. Blunty (who ought to find some real work to do...)
Is 1 sq m partictuarly large, small or indifferent? How does that compare to the average values for a Torndao or F15, for example? What is the minimum RCS you could expect an air intercept radar to detect at normal operating frequencies? What about a ground mapping radar? Your reply needs more information to be complete (well, for those of us who don't know these things anyway!).
I did a google to try to answer the above myself, but couldn't find anything. However, I did learn:
When the object's size spans several wavelengths, the RCS of a target object is equal to the cross-sectional area of a perfectly conducting sphere that would produce the same magnitude of reflection as that observed from the target object.
Every day is a school day!
Blunty
Edit: Further research suggests that the typical RCS values for a fighter type ac range between 1 and 50 square metres. The main variables are aspect, and frequency. This information taken from the very useful http://www.aerospaceweb.org/question...cs/q0168.shtml , if you're interested. Blunty (who ought to find some real work to do...)
Gyro matey,
I would suggest that if you don't wish to be regrettably schwacked by an unsuspecting GR/TmkSomething a wise man would do well to fly at/above 1000ft AGL, thus avoiding the vast majority of low flying military aircraft, bearing in mind that most of them don't have a radar capable of seeing you in the first place, even if they were paying attention to it at 250'!
I would suggest that if you don't wish to be regrettably schwacked by an unsuspecting GR/TmkSomething a wise man would do well to fly at/above 1000ft AGL, thus avoiding the vast majority of low flying military aircraft, bearing in mind that most of them don't have a radar capable of seeing you in the first place, even if they were paying attention to it at 250'!
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Originally Posted by pba_target
I would suggest that if you don't wish to be regrettably schwacked by an unsuspecting GR/TmkSomething a wise man would do well to fly at/above 1000ft AGL, thus avoiding the vast majority of low flying military aircraft, bearing in mind that most of them don't have a radar capable of seeing you in the first place, even if they were paying attention to it at 250'!
Blunty