What are people's views on this? (PCAS)

[Deano777]

clicky (http://www.transair.co.uk/Category.asp?SID=1&Category_ID=1369)

basically as title, I am thinking of buying one, and I know what all your arguments will be, and that is "look out the damn window", well that is all very well but if all parties concerned are not looking out their window then you can get yourself in the proverbial sh*t, yesterday for example, after climbing out of EGxx, levelled off, then passenger said "did you see that? we nearly had a mid-air collision", I basically saw nothing, apparently a C172 missed us by 50ft, flying over us from our 4 o'clock, I was keeping a good look out (so I thought) but was he? same as when you are driving a car, you can be the best driver in the world but you cannot control other human beings.
Now after recent events I guess you could say I am a little hasty and that I have been spooked a tad, maybe I have, I am not afraid to admit, but the biggest thing that scares the living sh*t out of me is leaving my 2 young daughters without a dad knowing they will grow up having never really known me, my mate was killed along with his sister before Christmas last year and he left behind his 5yr old daughter, even she will grow up without really knowing him.
I'm digressing a tad now but you get the general idea, and with the introduction of Mode S (no flaming please) these will do part of the job even more? basically it can be a great aid to collision avoidance but never substitute the good ol' eyeballs out the window but as it can be seen above, anything that can warn you of traffic proximity has to be a good thing?

Thoughts & comments please, and leave the negative flaming responses at home :)

Dean

[robin]

The ones with the detector lights only are a bit of a frightener as it only gives a range.

Certainly buy one which gives you height and distance, but it will only work with transponder-equipped aircraft. Don't assume that because the PCAS is clear, so is the airspace

[Deano777]

Hi Robin

Yes I absolutely understand that, that's why I made the comment about Mode S, I have had to dodge the odd aircraft not equipped after a spot by ATC before

Thanks for the comments :ok:

[robin]

Sorry if I'm teaching grandma..., but the current PCASs pick up Mode A and Mode C, not just Mode S

[mazzy1026]

Anything adding to saftey is good in my book, but you have to be careful not to fixate your eyes on this device too much, resulting in not looking outside ;)

[IO540]

The £1300 unit at the top of the URL you post gives azimuth information, and that looks pretty good (if it works).

The £15000 installed GA system probably isn't a whole lot better - other than offering decent integration with existing avionics like MFDs.

One problem is that this is a purely passive receiver, relying on ground radar interrogation of the Mode C/S equipment on the target, for the target to get picked up by your box. I would guess that in the UK this will be OK, since there are loads of radars around (even if a pilot cannot get a service from most of them :) )

However, the biggest problem with any form of TCAS is that when flying OCAS most targets are non transponding. Lots of planes don't have a transponder. Also, lots of pilots have one but choose to exercise their civil liberties :yuk: by not switching theirs on. This also enables them to bust airspace (vertically) without getting caught, which is really smart (not). This comment is based on 5 years' flying, and using a radar information service whenever available, and finding that most reported targets are "level unknown" which makes the service close to useless. Occassionally one gets a visual and sometimes the silent target turns out to be a brand spanking new plane which obviously came with a Mode C.

Higher up, say 4000ft+, most targets appear to be transponding, but then the GA traffic density is orders of magnitude lower. Most UK GA moves about below 2000ft, it seems.

And if flying in CAS or airways, one gets a radar service, and everybody is supposed to have a Mode C/S transponder anyway. 99% of other traffic up there is commercial stuff, and at nonpressurised levels you will be so alone that you may not see another plane (anywhere near your level) in many flights.

I wouldn't spend the money. If I was spending money, I would get some sort of ground proximity warning system. One day, that might save my life. There is a lot more ground to hit that there are other planes :)

[NoTurningBack]

D777,
I bought a Traffic Scope about 8 months ago and have found it of limited use.
It provides audio warning of other traffic which tends to make sure your heads outside trying to find it without having to look at the unit and reducing your natural lookout.
I'm surprised at the amount of low level traffic that do not appear to be Transponder equipped. All aircraft that I've flow have had 3a/c transponders.

I'm not sure that I would buy one again.

NTB

[tmmorris]

Surely the point of the Mode S comment was that everybody will then have to have a transponder with Modes A and C as well, so there should be no non-transponding traffic for it to miss?

T

[robin]

However, the biggest problem with any form of TCAS is that when flying OCAS most targets are non transponding. Lots of planes don't have a transponder. Also, lots of pilots have one but choose to exercise their civil liberties :yuk: by not switching theirs on. This also enables them to bust airspace (vertically) without getting caught, which is really smart (not).

I'm not sure you can make that logic - some pilots don't switch on their transponders properly because

a) they are not taught to use ALT
b) it may be inoperative, and transponding is not yet mandatory
c) there may be an electrical load issue
d) they may just have forgotten

..and yes, some do it because they are unsure of their ability not to fly into CAS, although why, I can't imagine

[robin]

...and some are not transponder equipped. You can never tell what the avionics are from the outside

[Deano777]

Surely the point of the Mode S comment was that everybody will then have to have a transponder with Modes A and C as well, so there should be no non-transponding traffic for it to miss?

T

Exactly what I was trying to say tmmorris thanks :ok:

[Rod1]

Don’t assume Mode S will be universal, the French have just exempted 8000 microlights and most of Europe will do the same.

You will find a large number of Gliders, probably non-radio and certainly not transponder equipped, above 4000 ft, some in cloud….

Rod1

[Deano777]

D777,
I'm surprised at the amount of low level traffic that do not appear to be Transponder equipped. All aircraft that I've flow have had 3a/c transponders.

I'm not sure that I would buy one again.

NTB

NTB, if yours is surplus to requirements send me a PM with how much you want for it ;)

I wouldn't spend the money. If I was spending money, I would get some sort of ground proximity warning system. One day, that might save my life. There is a lot more ground to hit that there are other planes

I guess that is true, however, the only way you are really going to hit the ground when flying VFR is due to some kind of malfunction or pilot error, I can't see that CFIT arguments can be used when flying VFR unless you inadvertantly enter IMC, (I know it happens) but then you have to question why you are flying in the first place? ( yes, there are times when the wx is not as forecasted), personally I think an airprox is more likely to happen than hitting the ground, thoughts always welcome of course :)

[gasax]

VFR aircraft collisions are pretty rare. There are some really good things out there in terms of improving lookout and actually spotting other traffic. Conditions can make a big difference but gadgets are unlikely to help. With over half of the present registered aircraft being unlikely to have transponders then the gadget is probably not the answer.
Work on your lookout - it is amazing how much you can improve it by concentrating on a good scan, working at focusing from near to far and looking for very small targets. I rarely fly in straight lines, avoid obvious honey pots and make of a point of trying to visualise where other traffic on the frequency is. I've still been surprised - but thankfully never that close.
Even if we all end up with Mode S boxes there will still need to be some other system, aircraft TCAS or ground collision warning - technology is unlikely to fix the problem.

[drauk]

I've personally flown with a friend's MRX PCAS. I wasn't very impressed. The fact that all you're given is a relative height and range means the target could be almost anywhere, so you're not inclined to take too much notice.

I've heard that the XRX that gives a relative position is a little better, but someone I know that used to fly with one says that it reports traffic that just doesn't exist, so again, after a while you tend to ignore it. He sold it.

Lastly I've flown in the US with a Ryan TCAD traffic sensor - a $20,000+ device which shows traffic on your MFD. It was fabulous and worked very well. However, as lots of people have said, plenty of traffic doesn't use a transponder for various reasons, so even this is far from foolproof in an environment where they're not mandatory.

On that topic I've never known an instructor that didn't recommend turning it on, to Mode C. I have known pilots who refuse to use Mode C in the case they bust CAS.

IO540 flies a lot of IFR, hence CFIT is decidedly possible. In VFR it's much less likely obviously.

[scooter boy]

Just had a BF Goodrich/L3 TCAS interfaced with the G1000 in my Mooney by Rheinland Air Service over in Germany.
On the way back to blighty in the airway I was aware of a lot of metal around that I would have otherwise missed.
I agree that it is of limited value outside of CAS but I would much rather have it than not.
SB

[IO540]

Surely the point of the Mode S comment was that everybody will then have to have a transponder with Modes A and C as well, so there should be no non-transponding traffic for it to miss?

I would check this out. I think (should damn well know, having a GTX330) that you can switch off altitude reporting on a Mode S transponder. This is bound to be done by some d1ckheads who want to be able to bust airspace vertically but who have to carry Mode S.

A transponder not returning altitude is useless for traffic avoidance purposes.

Don’t assume Mode S will be universal, the French have just exempted 8000 microlights and most of Europe will do the same.

Another reason for not spending money on TCAS then :)

VFR aircraft collisions are pretty rare

Rare but not zero, especially around busy GA airfields of the "free for all" type.

Practically nonexistent in IMC, presumably because so few GA pilots fly in IMC.

b) it may be inoperative, and transponding is not yet mandatory
c) there may be an electrical load issue

b) is a bit selfish IMHO. The pilot may as well paint a big finger sticking upwards on the side of his plane. c) is pretty unlikely if the thing has actually been fitted!!


So, the statistical case for TCAS is pretty poor. It's better to have a warning (assuming the direction is provided) than not, of course. I would just spend the money on a very very good GPS, not the usual piece of junk from a camping shop - that will do more for one's flying.

IF Mode C was mandatory then TCAS would be great. I think this is unlikely to happen in the UK (Mode S for all VFR traffic) because of the technical problems with equipment carriage and power.

I don't believe in a lookout being very useful. I know a lookout is one of the cornerstones of aviation (alongside dead reckoning and leather helmets and goggles) but assuming straight line trajectories a target on a true collision course will be a stationary point until it hits, so those you spotted were in fact not going to hit (no matter how close they seemed at the time). I look out very carefully for gliders, and try to fly above clouds where they won't be anyway.

[Deano777]

VFR aircraft collisions are pretty rare. There are some really good things out there in terms of improving lookout and actually spotting other traffic. Conditions can make a big difference but gadgets are unlikely to help. With over half of the present registered aircraft being unlikely to have transponders then the gadget is probably not the answer.
Work on your lookout - it is amazing how much you can improve it by concentrating on a good scan, working at focusing from near to far and looking for very small targets. I rarely fly in straight lines, avoid obvious honey pots and make of a point of trying to visualise where other traffic on the frequency is. I've still been surprised - but thankfully never that close.
Even if we all end up with Mode S boxes there will still need to be some other system, aircraft TCAS or ground collision warning - technology is unlikely to fix the problem.

Good advice gasax, I'll give another scenario, today (Tuesday) I was flying towards Ledbury and in contact with Gloucester Approach, an aircraft gives a position report, "currently overhead Ledbury at 3,000ft inbound", and I was 3 miles SE of Ledbury heading towards it from Gloucester at 3,000ft, could I spot this aircraft? absolutely not, I looked & looked but could not see it, I tried all sorts of eye focussing, i.e. below/above horizon, far/near etc and he was nowhere to be seen, this worried me a tad, 3 miles is nothing if you are closing on one another as you well know, but as for where he was? who knows, he must have had a sky blue plane :)

(it makes it sound like I don't spot anything, I spot a hell of alot, but it only takes one that you don't spot to end in disaster)

[Human Factor]

Get one by all means, it enhances safety. But:

It only works based on reaction with transponder equipped aircraft and is designed as a complement to your lookout, not as a replacement.

[Deano777]

Get one by all means, it enhances safety. But:

It only works based on reaction with transponder equipped aircraft and is designed as a complement to your lookout, not as a replacement.

Yes that is appreciated, similar to the old argument about GPS vs Map & Compass

[whiskeytangofoxtrot]

I can't see that CFIT arguments can be used when flying VFR unless you inadvertantly enter IMC, (I know it happens) but then you have to question why you are flying in the first place?
Another case would be VFR night flying over a non-flat terrain even with good weather, especially if the area is very sparsely populated.

To get back to the topic, I think the most dangerous phases of flight considering midair collisions are approaches and departures to and from active nontowered airports. In places like this the density of traffic is already pretty high, so even if you had such a device, its usefulness would be quite limited - wouldnt it scream all the time anyway?

[IO540]

I have been developing electronic products for about 30 years; done hundreds of them, hardware and software. But this

is designed as a complement to your lookout, not as a replacement

is really interesting. How does one design a product to do that? Must be a new technique I have missed out on for all those years. Can anyone please elaborate?

[bookworm]

There are some really good things out there in terms of improving lookout and actually spotting other traffic.

How do you assess your "improved" lookout? The problem is that you only see the ones that you see. And the vast majority of those, because they're not on a collision course, are easier to see than the one that will actually hit you.

Most of us who use radar services or TCAS are used to the situation that Deano777 describes: a contact that gets frustratingly close that we never actually see. Sighting tests conducted in the US 15 years ago with GA pilots came up with the result that about 50% of potential collisions were never seen, and of the remainder a large proportion were seen too late to take reliable evasive action.

We delude ourselves into thinking that better lookout is the answer. While it undoubtedly has a role to play in managing risk, the fundamental limitations of human perception mean that we should be using all the effective tools we can.

Of course not every electronic gadget is as effective as another, as drauk points out. Azimuthal (relative bearing) information is critical, and is an essential part of TCAS. I'd be interested to see whether the azimuthal information provided by the PRX is truly valuable. My impression of flashy-light boxes is similar to his -- more of a distraction than a help.

[wsmempson]

Crossing the channel yesterday pm via the VFR route through DA036 and approaching 50 deg N, I became aware that Plymouth Military were talking to someone on a reciprocal heading to me who I couldn't see for the life of me. I told Plymouth that I was going to switch my landing light on to give the other chap a chance to see me, and the other pilot did the same and, low and behold, we could both suddenly see each other.

We were surprisingly close and although the vertical seperation would have been fine, neither of us had seen each other because we had both been more or less stationary from one anothers point of view.

At the risk of suggesting that we ape 1970's Volvo drivers, I have a suspicion that the most useful thing we could do as pilots would be to turn our landing lights on...I know they burn out quickly and are relatively pricey, but anything that helps the Mk1 eyeball can only be a good thing.

[IO540]

Very true about lights, and their short life.

There is a solution to this

http://www.speedmods.com/Boom_Beam/boom_beam_systems.htm

(and others, e.g. Nelson)

Just try to get the CAA/EASA approval to fit this great safety aid to a G-reg :ugh: :ugh: :ugh:

Ok for an N-reg.

[englishal]

What amazes me is the amount of traffic you don't see, which suddenly pops up on the screen, draws your attention to, and then you do see it. I have flown in G1000 aeroplanes with TIS in america, and it is the best thing since sliced bread in my opinion.

You know, if someone came up to me and said "here, buy this GPS unit, it has a built in transmitter and re-transmitts your position for about 10km. It also has a display in and receives all transmission from aeroplanes within 10km and displays them relative to you, and it only costs £500".....I would buy one. I wonder how many other GA aeroplane owners would stump up £500 for a device like this (in our group of 4, it'd only cost us £125 each)....?

The technology is cheap, and very feasable. However, I think there would be real trouble marketing this to 90% of UK GA.......Shame really.....It'd be a good little earner for an electronics firm as well ;)

[scooter boy]

Englishal, you are absolutely right about the beauty of TIS/TCAS. Sometimes our visual cortex is unable to register the presence of a moving target until it becomes uncomfortably close and this demands our full concentration and creates distraction in the cockpit.

So why don't Eurocontrol or EASA or whoever has the power to do so switch on the TIS so that those of us with mode S equiped aircraft can at least see eachother.
Personally I value my own life far more than the price of a mode S transponder.

SB

[IO540]

So why don't Eurocontrol or EASA or whoever has the power to do so switch on the TIS

I suspect they would need to spend money on some equipment.

Also you would not be able to see it unless you have something the size of a GNS530, or a reasonable MFD, and the group of pilots that have that sort of kit in Europe is very very small, and not very vocal. They go about their flying quietly. A lot of them fly in CAS, under radar control, and then the need is that much less.