I originally started this thread to see what people thought about the idea of a piece of cheap equipment that would not require any communication FROM other traffic for an a/c to know of that traffic's existence.
I would aggree that the GPS is not the answer, I think I got a bit off my original track by suggesting something to be carried by all.
What I think is needed is some form of onboard primary radar like the military "target aquisition" stuff but at an acceptable price. Something simple that will detect a chunk of aluminium heading your way, with no input from the "target". Of course this will never happen as if it were possible "someone would have done it by now". Where have I heard that before?
However as for "looking out the window", I presume you believe that I need to be advised to do this?
Perhaps I should point out that, contrary to popular belief, not all student pilots are as thick as two short planks. Whenever I fly from my local flying school I do try to get a window seat, so far I have always been successful & always in the front.
I spend the entire flight looking at the view apart from the occasional glance at those clock things.
These last remarks are not directed at you or anyone personally, but I have read "look out the window" so many times that I feel I must answer I DO!!! But I can't see through the roof or the floor. Please don't tell me what the yoke or stick is for.
Now, why don't airline pilots do that & make the whole thing a lot easier, put CAA, NATS etc out of business?? Or is it just the poor light GA non commercial VFR pilot who has to do it, while the big boys sit doing the crossword or playing chess?

"What I think is needed is some form of onboard primary radar like the military "target aquisition" stuff but at an acceptable price."

That is naiive in the extreme. Do you have any idea what 'military target acquisition radar' actually is? The acquisition cost, installation cost, power requirements and siting difficulties of even a simple cloud and collision warning radar in a SEP spamcan would be enormous. Let alone the CAA mod fees.... Let's just say tens of thousands of pounds.

You have to realise that all the silicone chips in the world won't be enough to protect you from other aircraft under VFR.

Remember, Visual Flight Rules mean just that!

I am not quite that naive.
I am well aware of what military "target aquisition radar" is. I was not proposing canibalising a Tornado. Lets forget the military stuff & try from another direction.
Some altimeters are expensive & are hooked up to expensive transponders, other altimeters are cheap & can be strapped to ones wrist so one can leap from an a/c & know roughly when to pull the string.
Both read altitude.
Now, current primary radar systems are expensive, complex, heavy, big etc. So I don't propose ransacking West Drayton.
However, intruder alarm systems have a very short range, could that be improved? infrared cameras have a slightly longer range, could that be improved? Some expensive cars I believe are fitted with proximity detection systems to prevent rear ending the guy in front, how much £ & how far in front?
I'm sorry I am merely a thinking person, I am a retired toolmaker / machine designer, I am not an electronics man at all. but I can think "what if, based on current technology?"
OK it may not be possible, certainly if CAA certification has to be considered, price wise. So much for progress. But a few years ago TCAS wasn't possible.
I suppose we just have to wait, grin & bear it, pay up, shut up & generally cowtow to them what know better.
Would Mr Trevor Bayliss please stand up!!:ugh: :{

One example of what you may be thinking of is a radar altimeter. These send a beam, fairly wide, downwards and measure the time delay.

A KRA10 is about £6,000 installed. Still too expensive for most spamcans. OK, the manufacturing cost is about £300 (same as a Garmin 530 for that matter) but that's the way things go...

Detecting a target without a reasonable idea of azimuth is not much use. Which is why the cheap £500 traffic warning boxes are useless, IMHO.

Even the latest TCAS technology cannot provide azimuth conflict resolution....

A 'radalt' actually uses radio, not radar. The emitted signal is frequency modulated and the difference between the frequency of the reflected signal and the main signal sent at the time provides an indication of height.

We had a radar altimter in the Vulcan, as well as the radio altimeter. Used for accurate high level height measurement, it was a huge and very expensive device!

That's the way to do it!
 

There must be something better than the mark one eyeball! You're thinking about it in the context of current GPS receivers, but why would you want to start from there, when it has all the problems you listed?

The kind of device that's required would simply have to broadcast its GPS position, using the same technology as wireless broadband. The amount of data involved (ID +coordinates) is tiny, and by transmitting at low power, so that only nearby aircraft could pick it up, the bandwidth should not get saturated and the current consumption should be low. The back end processing would involve keeping a list of the most recent positions and using that to calculate the track of each aircraft, so that conflicts could be identified. Such a device should be able to operate on rechargeable lithium cells, so there would be no excuse for even gliders not to install it.

Hopefully, by publishing the idea here first, nobody should be able to patent it, so competition should keep the price low. :)

It does in fact have to carry a few miles. The closing speed of a 150kt spamcan plus a 737 can be quite high. A few miles' range needs more RF power than one is going to get with small lithium cells.

Anyway, as has been written here already, 1090ES is the way to do this. It's established and internationally accepted.

The reason prices are not as low as they could be is that certified avionics is an international cartel, allowing stuff to retail at 10x to 20x manufacturing cost. Everybody except the end user loves it; the avionics shops like the reseller margins, the installation charges, the distributors like their margins... and this "find a stream of money and position yourself alongside it" is what keeps the whole world rolling along nicely :)

On Permit planes, one could do a lot.

I am sure products are being developed right now. But nobody, not even a bold new player who has nothing to lose in bombing the market and pi**ing off the distribution networks, is going to announce a product now, before Mode S is mandatory. This is because he will know that Garmin, etc, could push out a sub-£1000 version of a GTX330 within a few months if they wanted to, and why show your hand early?

BTW, a KRA-10 is a radar altimeter

https://www3.bendixking.com/static/c...ils.jsp?pid=83

You're right! I guess that's the result of modern radar development.

Similar to the 'parktronic' devices fitted to some cars - although with a bit more wattage!

I don't know why these pieces of kit need to be so expensive. You could knock up a cheap Radalt for a couple of hundred quid these days, if that.

I like the idea of re-radiating ones GPS position. If everyone did it, there would be no need for transponders or even radar. Could even use the Mobile phone cells to collect the data, with no additional infrastructure required. Send it off via Inmarsat and you have glodal coverage.

I'm sure NATS and their suppliers would love that!

... which is why Air Services Australia, with huge amounts of airspace to cover, are so smitten with the idea that they may well subsidise equipage with ADS-B over 1090ES so they can save $100 million on radar systems.

Great guys, this is nearer the right direction.
Broadcasting GPS units sounds good, & the technology doesn't sound impossible, I wish I knew more about the electronics stuff, there are other markets for that as well, I'm sure the Mountain rescue services would appreciate a distress call with a pinpoint location included, especially when the poor sod that fell down the mountain doesn't know where he is. So going a step further & add a button that changes the signal to a distress call shouldn't be difficult. I'm sure a lot more people than just the aviation industry would be interested, mass market = cheaper?
The problem of azimuth resolution may not worry many people, just the knowledge that something is on a converging track would do me.
As for upsetting NATS etc, why should that be a problem? If it were self contained ie:- not hard wired to the aircraft, would that make it unregulatable?
As for a radar based device, how much wattage / amps is required to return a signal from say 10 miles? If that requires a battery the size of a porta-cabin then it's no use.

Simple cheap collision avoidance
 

Flarm does this; GPSs that talk to each other within 1-2nm. Developed for glider pilots in the Alps.

Not proposing or advocating anything, just pointing out a nifty bit of kit.

I am sure that all pilots out there ( whether commercial or GA) would, if presented with a simple to use, low cost (say £250 fitted), low power (ie nicad rechargeable) unit that would be able to be shown,without doubt, to enhance the safety of us all; then we would all purchase and install the same. So then surely, this should be given as a task to the CAA to commission the design and manufacture of such a unit providing a clear case as to how it will enhance the safety of aviation as a whole, on the clear understanding that we would all purchase and install the kit.

If this was so tasked to the CAA then I can safely say that we would hear no more of mode 'S' or any other similar unit until at least 20 years hence ( by which time there probably wont be a CAA anyway)!:8

That's what we've been saying all along. In their proposal the CAA claim to have taken a leading role in the development of the low-powered, low-cost transponder.

But when you ask them just what that means, they look all shifty and tell you that it is not for them to mess with the market.

My own view is that they know that sailplanes, microlights and very light aircraft won't go for anything over £1k, and have sort of been saying that Mode S won't be mandated unless there is a cheap one available - at the Safety evening a figure of around £500 was bandied about.

But, the CAA are not doing anything to make this utopian piece of kit happen.

By all acounts, those in the know are finding the CAA very hard to deal with on this matter. They have put in years of work with the aim of having Mode S installed on everything, and they are not going to let a small thing like making 28,000 aircraft owners pay out huge sums of money stop them from going ahead.

My gut feeling is that we will see this go to judicial review.

And isn't their so-called low-cost, low-power Mode S device to be restricted to VFR only?

Not much use to those who can currently fly in IMC with Mode C quite safely.