God bless TCAS [Archive]

scooter boy

19th Sep 2006, 22:13

Just a quick thought before I go to bed for all those TCAS nay-sayers out there.
This morning as I was in the descent in to Gloucester in VMC at about 0800 (on indemnity as they do not open until 0830) passing 2500ft about 10 miles South of Staverton my newly installed BF Goodrich TCAS picked up traffic apparently heading in a reciprocal direction and climbing out of Staverton. I had just signed off with Filton and I had already made 1 blind call to Gloucs traffic so I put my landing lights on and made another call for good measure. I had apparently missed the departing aircraft's calls and would guess he was speaking to ? Brize Radar - maybe he had me on TCAS - maybe Brize had advised him of my proximity - maybe not.
As we drew closer the traffic got upgraded to proximate traffic :bored: (looks just like this emoticon in fact but with an altitude trend and relative altitude tag) and I got a verbal annunciation through my headset before I was visible with the twin that was climbing out (King Air?) at a distance of half a mile. I increased my rate of descent in order to be at least 500 ft below and we passed one over the other with safe separation at a closing speed that must have been in excess of 350kts (I was doing over 190kts).

My point is - this all happened within a time frame of about 2 minutes and I got a hell of a lot more warning of impending collision than if I were using the mark 1 eyeball (I had 3 seconds visual contact as we passed) - this early warning enabled me to maintain safe separation without extreme maneuvering. Without TCAS it would have been a lot closer as my planned descent track would have had me right on top of him.
TCAS is worth every penny in my opinion - it really is great. It may have saved my bacon.
God bless you Mr Goodrich :D for you have purveyed a truly great gadget at a price that I consider vastly inferior to that of my life. :ok:

SB

TCAS FAN

19th Sep 2006, 22:27

Amen

You see why I love it so much!

zkdli

20th Sep 2006, 07:12

It's a good thing that the other aircraft had a transponder.... or is that another thread?:)

IO540

20th Sep 2006, 08:03

Well yes we can thank god (or not) that one doesn't see the other 95% of traffic, because they are not transponding. Ignorance is bliss, some might say.

scooter boy

20th Sep 2006, 10:17

IO, I would totally dispute that 95% of the traffic is not seen by TCAS.
Where does that figure come from?

Is it that 95% of all GA aircraft are not xpdr equipped?

That is very different to 95% of all traffic not being visible on TCAS because the xpdr equipped A/C fly far more hours and generally in worse conditions.

When Exeter or Plymouth tell me that there are 5 or 6 locally flying VFR aircraft in their area I see them almost always and usually with a mode C readout.

In my experience comparing the mark 1 eyeball with the TCAS the contrary is true - 95% of all traffic is visible on TCAS, especially in poor weather and at higher levels.

It is truly a beautiful thing and I hope to never fly without it.

SB

robin

20th Sep 2006, 10:49

When Exeter or Plymouth tell me that there are 5 or 6 locally flying VFR aircraft in their area I see them almost always and usually with a mode C readout.

In my experience comparing the mark 1 eyeball with the TCAS the contrary is true - 95% of all traffic is visible on TCAS, especially in poor weather and at higher levels.

It is truly a beautiful thing and I hope to never fly without it.

SB

Whenever I have the joy of flying into the Devon Strut fly-ins I notice that most of these aircraft are not transponder equipped.

At Branscombe in July there were around 80-100 aircraft 10 miles from Exeter positioning to land at various times during the day. I would strongly doubt whether your TCAS would have been able to see most of them, let alone identify a Mode C readout from them.

And it is worrying that you feel that your TCAS is better than Mk1 Eyeball in a very active area of PFA/Microlight/glider flying.

Yes TCAS is extremely useful, but is not the answer in all situations. It is also true that it helps in poor weather and at altitude, but by definition the PFA types won't be there.

IO540

20th Sep 2006, 10:59

The figure is based on flying under a radar information service and seeing how many of the reported contacts are "level unknown".

The % clearly varies with the altitude. Probably below 2000ft the % is at least 90%. If you encountered a lot of microlights it would be higher still. With gliders it would be close to 100%.

Above say 5000ft, nearly everybody is transponding but IMHO that reflects the different sort of pilots, different planes and probably also flight rules (not many VFR-only people will be flying at 5k in the UK) that fly higher up.

I would buy TCAS tomorrow if transponders were mandatory for VFR. But they are not and - without wishing to start another Mode S thread - I can't see that they will become mandatory for microlights and similar. However, few people flying those types (that I think will be exempted) fly above say 2000ft and flying "high" is thus a very good defence for traffic enroute. So the case for TCAS OCAS in the UK isn't that good IMHO, for for the installed cost of £10k-15k.

The risk with terminal (circuit) traffic remains and I suppose the usefulness of TCAS will depend on the traffic mix you get at the airfield you are going to. If it is microlight-heavy then TCAS will be of little use. You just have to keep the best possible lookout and hope for the best, for the few minutes that you are in the circuit.

Robin - the Mk1 eyeball so beloved of aviation traditionalists is actually pretty useless, but let's not ruin such a fondly held and propagated legend that has seen off Germany in two world wars :) A plane on a true collission course will be a completely stationary point, until the impact. I think this is a problem which just does not have a comprehensive solution.

robin

20th Sep 2006, 11:17

Robin - the Mk1 eyeball so beloved of aviation traditionalists is actually pretty useless, but let's not ruin such a fondly held and propagated legend that has seen off Germany in two world wars :) A plane on a true collission course will be a completely stationary point, until the impact. I think this is a problem which just does not have a comprehensive solution.

Actually, I agree with you. Over about one or two miles even being told where an aircraft is doesn't mean you will see it, especially if it is on a converging course

My point is simply this - if you rely on a piece of electronics to tell you where potential conflicts are, then inevitably the lookout will begin to suffer. Especially if you are used to radar controllers telling you where things are - you will listen to the voices in your head and the little bleeping box on the panel. It is still your responsibility to look out the window from time to time - how frequently depends on the nature of the airspace.

At the speeds I fly and the levels I operate at, lookout is key, especially close to airfields. At some events I have attended most, but not all, aircraft were radio-equipped and were punctilious in their position reports. I wouldn't dream of assuming that I knew where all the aircraft were from radio calls, so I take the same view of TCAS

tonyhalsall

20th Sep 2006, 11:17

A plane on a true collission course will be a completely stationary point, until the impact. I think this is a problem which just does not have a comprehensive solution.

IMHO this is not widely appreciated and the plain fact is that it is very easy to spot moving 'targets' - ie all the one's that won't collide with you. Not so easy to identify a spot that just gets bigger.

Great point

scooter boy

20th Sep 2006, 11:53

And it is worrying that you feel that your TCAS is better than Mk1 Eyeball in a very active area of PFA/Microlight/glider flying.

Robin, what made you think I had my eyes inside the cockpit all the time? :rolleyes: If I was in a string and basket triplane without a GPS far more time would need to be spent looking at the map and worrying :bored: whether I was about to enter CAS inadvertently.

There is no argument here - TCAS is better than the mark 1 eyeball at spotting xpdr equipped contacts in any weather conditions, period, end of story.

This of course doesn't mean that I no longer use my eyeballs and it is absurd of you to feign concern at this assumption - I simply have additional direction finding equipment that tells me roughly where to look (as well as maintaining a full scan when I am in VMC). Let's not get into the sextant vs GPS argument about how all new technology is fine til it quits etc... this is a tedious one and I don't want to get IO started.

My point has in fact been reaffirmed by IO540.
When you are on a direct collision course (as I was) you need all the help you can get.
Even you eagle eyed handlebar moustached PFA types (I flew a PFA aircraft for 6 years) would struggle in a nose to nose situation - you would have a couple of seconds max in which to react.
The decision as to whether to fit TCAS is a financial and technical one - for me it has been an epiphany and all I wanted to do was share that with you.

Technology of this sort is simply a useful adjunct to the stick and rudder skills that we all have.

BTW there were no gliders, PFA types, balloons or microlights around between 0720 and 0800 on my route of flight - no thermals and Wx around Bristol was poor.

SB

scooter boy

20th Sep 2006, 11:57

[quote=IO540;2862501]The figure is based on flying under a radar information service and seeing how many of the reported contacts are "level unknown".

Is that level unknown or unverified?

Two different things.

Most of the contact that I see as pop-ups have a level tag right next to them.

SB

robin

20th Sep 2006, 13:21

Robin, what made you think I had my eyes inside the cockpit all the time? :rolleyes: If I was in a string and basket triplane without a GPS far more time would need to be spent looking at the map and worrying :bored: whether I was about to enter CAS inadvertently.

There is no argument here - TCAS is better than the mark 1 eyeball at spotting xpdr equipped contacts in any weather conditions, period, end of story.

This of course doesn't mean that I no longer use my eyeballs and it is absurd of you to feign concern at this assumption - I simply have additional direction finding equipment that tells me roughly where to look (as well as maintaining a full scan when I am in VMC).Even you eagle eyed handlebar moustached PFA types (I flew a PFA aircraft for 6 years) would struggle in a nose to nose situation - you would have a couple of seconds max in which to react.
The decision as to whether to fit TCAS is a financial and technical one - for me it has been an epiphany and all I wanted to do was share that with you.

Technology of this sort is simply a useful adjunct to the stick and rudder skills that we all have.

BTW there were no gliders, PFA types, balloons or microlights around between 0720 and 0800 on my route of flight - no thermals and Wx around Bristol was poor.

SB

How do you know there weren't any? You were airborne, so why not others?

My point is quite simple, and we will agree on this - as long as TCAS users are fully aware that they are only detecting other transponder equipped aircraft, and then only when they are squawking Mode C. I bow to your own judgement of your abilities, but I have seen too many pilots switching on their autopilot and going into 'bovine' mode to be able to trust fully-equipped aircraft to even pretend to lookout.

As a handle-barred moustache veteran and hero of the PFA fleet, I don't want a TCAS-equipped person routing through Class G and running into the back of me, because he thought the airspace was clear as he hadn't seen me on TCAS (this nearly happened to a friend recently)

As my little toy can't accommodate a transponder, don't tell me I have to fit one.

IO540

20th Sep 2006, 13:42

I have seen too many pilots switching on their autopilot and going into 'bovine' mode

Best to avoid phrases like that, IMHO.

An autopilot is the most fantastic reducer of cockpit workload, allowing the pilot to keep an eye on everything else - including looking outside.

Most accidents are pilot errors and most pilot errors would not have happened if the pilot had loads of time to think.

I like to fly manually some of the time, especially in IMC, but if I encounter any real workload, ON comes the autopilot immediately. If I was flying a microlight or permit type (which I may well be doing one day, when I get really old or go bankrupt) I will put in an autopilot. One can get some really good ones for non-cert types.

Most of the heroes in this business are either propping up the bar (with their hairy chests, gold medallions, leather caps and goggles) without actually flying anywhere, or they are 6 feet under because they messed up.

shortstripper

20th Sep 2006, 15:39

Most of the heroes in this business are either propping up the bar (with their hairy chests, gold medallions, leather caps and goggles) without actually flying anywhere, or they are 6 feet under because they messed up.

Best to avoid phrases like that, IMHO.

Horses for courses and all that. I appreciate your skills flying fast well equipped stuff and I'd hope you could appreciate my type of flying skills too (the "my" meaning all us PFA/BGA/MICROLIGHT types). We're not all bar props or dead, just like you're not all instrument fixated automatons!

SS

ShyTorque

20th Sep 2006, 16:51

Ah, again the dyed in the wool, "I'm harder than you" folks believe that those with TCAS only want one because they can't, won't, or don't look out, unlike PROPER pilots.
Again, a case of the 'head in the sand brigade' believing that everyone else is the ostrich! Nothing can beat the good old human eye, they truly seem to believe. Very few, if any, of these people have actual routine experience of using TCAS. They don't want it, or a transponder. They need to justify their "blinkered" view so they decry its use.
Having flown in Class G for nearly eight years now in TCAS 1 equipped aircraft (previously about 25 years without, up to 350 kts in Class G) the main point I have learned is that there are LOTS of aircraft out there, many of them unseen.
People believing they don't need TCAS are quite possibly of that opinion because they have routinely FAILED to see a lot of other aircraft and therefore underestimate the amount of other traffic actually out there!
Used correctly, TCAS can only enhance lookout. It has demonstrated to me time and time again the limits of the human eye, backing up everything the RAF taught me in that respect. The human vision IS quite limited for airborne use - because it was never designed to be used as such.
I know from my experience of using TCAS that most light aircraft often don't stand out at all well beyond 4 miles range against a mixed background. Given that my aircraft does 2.5 miles a minute and a light aircraft about 1.5, or even higher, this is 1 minute or less from unseen to a head on collision. I find it hard to understand how anyone prefers to decry a system that can indicate other traffic at far greater ranges.
BTW, an erroneous view was expressed earlier, TCAS WILL pick up a non-mode C squawk, but it obviously will not give an associated altitude readout.

tonyhalsall

20th Sep 2006, 17:10

JW411

20th Sep 2006, 17:56

It is good to hear someone out there questioning the good old Mk.1 Eyeball so beloved of many of our purists. I wonder if any of you out there have heard of empty field myopia?

This phenomenon is caused by the eyeball focusing on infinity and not being able to see objects up close.

I can remember being a student many years ago in a Vampire at altitude and being asked by my instructor if I could see the Valiant bomber converging at my 1 o'clock. I could see nothing. Sir asked me to look at my wingtip (to re-focus) and then look out again. There, almost in front of me, was this bl**dy great V-bomber which I could not see just a few seconds ago.

I was recently flying with my son and drew his attention to conflicting traffic. We had a re-run of the above and he was equally amazed that he had missed what he missed.

I already have a Mode S transponder and await with eager anticipation for the arrival of an affordable TCAS which I use and absolutely love in my day job.

ShyTorque

20th Sep 2006, 18:04

Excuse my ignorance......................
Presumably TCAS relies on other aircraft being txpdr equipped - and that the txpdr is switched on?
There are approximately 8 regularly flying aircraft in our barn and at the Club I am a member of at least another 60-70. None have transponders. Because they are microlights and 'cheap' to opearte they are regularly flying.
Is there any chance at all that TCAS could make you complacent?
Just a thought
No, that is my point entirely. Unfortunately, that is the most common fallacy put forward by those that haven't had the use of it.
In a TCAS equipped aircraft, you are constantly reminded that there ARE other aircraft out there, even when the sky LOOKS clear and used properly, as part of a lookout scan, it keeps your eyes OUTSIDE the cockpit, not inside.
We all know how many aircraft don't squawk (we see lots, often they don't see us or don't know the rules of the air) so TCAS CANNOT be a replacement for lookout and no-one who knows the system and uses it properly would ever believe it is.
Someone I have previously flown with, an ex-military pilot with many years of experience has survived TWO mid-air collisions. One aircraft hit him from behind, one from above, both whilst he was in cruise flight. He had no chance to see either. He told me that TCAS might have prevented both accidents. He is, quite understandably, even more paranoid about lookout than most but TCAS still beats his (class one medical, steely blue) eyes, time after time. The proof for me (class one medical, steely blue eyes) is that not infrequently we have a TCAS target go past within a mile in seemingly quite reasonable visibility and despite our best efforts, neither of us (2 pilot ops) can see it, or see it very late indeed.
My point is, don't decry it, until you've tried it. :)

scooter boy

20th Sep 2006, 18:21

My point is, don't decry it, until you've tried it. :)

Hear, Hear,
SB

shortstripper

20th Sep 2006, 18:41

I wasn't decrying TCAS, I was responding to IO540's post where he critisied one sweeping statement and then when on to make another!

TCAS I'm sure is great. I haven't used one but that doesn't mean I can't see it's advantages. However, aircraft like mine simply cannot be fitted with a transponder as they are in present form. I doubt we'll ever have a really practical light version that won't fry my balls or take up a small enough space to be fitted ... let alone a TCAS as well (although I can see they can be quite small). All the time aircraft like mine are allowed to fly (which I pray is for a long time yet) TCAS cannot possibly completely protect you. Surely there could be a better gps based avoidance system designed? Much smaller, better technology, probably cheaper and less likely to iradiate the pilot?

SS

tonyhalsall

20th Sep 2006, 18:58

I suppose with Mode S on the horizon it would certainly make alot of sense to have TCAS as well - I just don't know where I can put all these fancy gizmos.
It would most certainly have helped me in a very close airprox that I had with a C172 in August.
Loading up my microlight with gadgets such as Mode S, TCAS and solid state horizon may be very beneficial for safety but unfortunately it may well take me above my empty weight limit - but that is another debate.

Piltdown Man

20th Sep 2006, 19:19

And while we are at it, don't forget that squawking mode C will keep the bigger boys off you as well. It not unknown for some of our LoCo's to wizz about at speeds which will give a closing speed of 230 kts even if he/she is in your 6 o'clock. I recon getting a Boeing up your bum is a painful experience and one best avoided.

Marvellous stuff TCAS.

PM

Pegasus912

20th Sep 2006, 20:08

I don't think any right-minded pilot would argue against the benefits of TCAS. But as scooter boy previously commented, it's installation into the wider GA fleet is entirely a question of finance and technicality. I would install a transponder and TCAS tomorrow if it was cheap and didn’t take my ship overweight.

I just hope that quest for the elusive 100% safe airspace doesn’t end up grounding me and a large proportion of the rest of the GA fleet. That would be a very, very sad day.

Although it’s ludicrous to think this could even happen in aviation, I’m hoping that a cheap and effective solution will come along one day that everyone can install. Perhaps like Bluetooth for airplanes, constantly transmitting and with a few miles range so just enough for a warning against an air-to-air.

robin

20th Sep 2006, 21:31

In a TCAS equipped aircraft, you are constantly reminded that there ARE other aircraft out there, even when the sky LOOKS clear and used properly, as part of a lookout scan, it keeps your eyes OUTSIDE the cockpit, not inside.

Could you explain that statement?

How are you constantly reminded that there are other aircraft out there? My experience of flying with friends TCAS-equipped is that they only respond to TCAS alerts and aren't looking out more than I do

ShyTorque

20th Sep 2006, 23:31

Certainly. The TCAS display (in the aircraft I fly it's on the right of the instrument panel) is included in the left / right lookout scan. It takes a second or two to include it and assimilate a potential conflict. Believe me, no-one with a modicum of airmanship about them stares at TCAS for long periods of time, heads in.

On a clear day or less so, one can scan the sky and see absolutely nothing. In these circumstances, without TCAS, a pilot might be tempted in blissful ignorance to relax a little and fold a chart, or look up a frequency, or get eye contact with a passenger and make conversation, etc etc.

However, the TCAS screen perhaps shows targets ahead at various clock-codes, perhaps ten, eight, six and three miles away. Eyes return to outside and stay outside. No chart folding, no frequency look up, no eye contact and no conversation except "Where are they?" :eek:

Normally, before the time the TCAS gives us a "Traffic, Traffic!" warning, we have visually aquired the conflict, switched on the searchlight to increase our own conspicuity and already taken, or are poised to take appropriate avoiding action. The other aircraft presumably when not TCAS equipped, more often than not give NO indication that the crew have seen us until very late, if at all. We make a lot of avoiding action when the other pilot has made no effort to do so, despite his responsibility under rules of the air.

All I can say is, if your friends don't include the TCAS display in a lookout scan then they aren't using it properly.

chrisN

21st Sep 2006, 00:31

Pegasus912 wrote [snip] . . . I'm hoping that a cheap and effective solution will come along one day that everyone can install. Perhaps like Bluetooth for airplanes, constantly transmitting and with a few miles range so just enough for a warning against an air-to-air.

There is. Flarm. Unfortunately, CAA won't approve it, airlines appear to be uninterested and are pressing only for the impractical (for light and unpowered aircraft) Mode S, so we are stuffed.

Chris N.

shortstripper

21st Sep 2006, 03:00

Yes Chris, that looks a much better idea ...

http://lbs.gpsworld.com/gpslbs/article/articleDetail.jsp?id=308235

Far too sensible for the CAA to adopt. Maybe it's because whilst it would aid safety, it would not aid their tracking of us and allow the adoption of future airspace charges?

SS

bookworm

21st Sep 2006, 08:02

There is. Flarm. Unfortunately, CAA won't approve it, airlines appear to be uninterested and are pressing only for the impractical (for light and unpowered aircraft) Mode S, so we are stuffed.

FLARM performs the function of an ADS-B device with at least two significant differences.

1) It uses its own standards, so instead of having interoperability, everyone has to carry a FLARM device regardless of their other equipment. It doesn't interact with TCAS.

2) It is very low power, and therefore has a range of 2-3 km. That may be enough for glider-on-glider collision avoidance, but it's not nearly enough to be effective for larger aircraft.

If you were to start from scratch to produce a device that conformed to international ADS-B standards, was high-enough power to have the range for higher speed interactions, and was capable of responding to TCAS, you'd end up with something very like the LAST or LPST.

funfly

21st Sep 2006, 09:12

Oh dear the topic is going along the hate GPS lines!
I am interested in getting a TCAS unit for my light aircraft, I assume that you all may have the 'posh' expensive types in your aircraft but can you advise me if the small and less expensive units are OK, any suggestions on wjat I could buy?
G-BYZD

Rod1

21st Sep 2006, 10:06

We all know how many aircraft don't squawk (we see lots, often they don't see us or don't know the rules of the air) :)

So the pilots of less well equipped aircraft complain that the well equipped aircraft are not looking out of the window, and the pilots with the kit think that pilots without it do not know the rules of the air. What a great world we live in!:ugh:

I have no problem with you guys playing with your toys, but please do not try to make them compulsory. I like flying for fun and the idea of flying a computer leaves me cold. I assume the flight sim enthusiasts are the people who cannot afford to fly fully equipped aircraft.

The PFA and BMAA fleets combined offer about 5000 aircraft without Transponders, most without radio. The BGA will obviously add to this very considerably. Interesting that the number of people who actually fly into each other is so incredibly small. We would add more to flight safety by spending the money on an extra hour a year on stall/spin awareness than on collision avoidance. Perhaps an hour of basic aerobatics for all PPL’s would reduce the fatality’s more than compulsory transponders?

Rod1

bookworm

21st Sep 2006, 10:20

Have you considered the Zaon XRX? Until there's considerable ADS-B equipage, something like that is about the most effective a passive device can be.

robin

21st Sep 2006, 10:30

Hmm - £1200 !

And on top of that the prospect of a £2k transponder +fitting and CAA mod fees.

chrisN

21st Sep 2006, 11:05

CAA and its apologists (here and elsewhere) just won't listen to reason and only use facts which support their argument. Just some points:

"[FLARM] uses its own standards, so instead of having interoperability, everyone has to carry a FLARM device regardless of their other equipment. It doesn't interact with TCAS."

Yes. Mode S uses ICAO standards and has no interoperability with anything a glider, hang-glider, microlite, parascender or many small GA types can carry at present, so is useless to glider/glider or glider/most-GA or most-GA/most-GA collision risks. The ICAO standard was drawn up without heed to practicalities of implementation in many types type of glider, hang-glider, microlite, parascender.

"[Flarm] is very low power, and therefore has a range of 2-3 km. That may be enough for glider-on-glider collision avoidance, but it's not nearly enough to be effective for larger aircraft."

(a) I would rather know about the rare airliner in class G if it gets within 2-3 km of me than not know, and I would certainly rather know about other gliders and the rest of GA with whom there is a much greater prevalence at the heights and in the places I fly, and with whom there is a much greater collision risk. Unfortunately, CAA and their apologists just don't care about that.

(b) If as much effort were put into R&D for Flarm reception by airliners etc. as is being funded for UAV's, Mode S, and other safety or airspace-capacity issues, no doubt Flarm detection range could be improved. There are none so deaf to the possibilities as those who don't want anything but their preconceived (and ill-conceived) part-solution.

CAA's proposals for a slightly more practical LAST/LPST have not been adopted by ICAO or anybody else. While it is still in negotiation, why not add Flarm to the possibilities?

Certainly Flarm won't register on TCAS - but TCAS-equipped airliners etc. could more easily fit a Flarm too than I can fit a LAST with power enough for a 12 hour flight, let alone hanggliders etc..- and I can't fit a TCAS at all, neither can most (AFAIK) of the rest of GA.

I have no more wish to be in a collision than anybody else. My greatest risk is from other gliders etc.. The right technology could be so much better than the eyeball. Repeated statements of legal and moral obligation to look out effectively will not improve our biology or mental processing power. Most collisions involving gliders, and I suspect power too, involve impact from the rearmost 180 degrees where the eye does not work. Even in the front 180 degree sector, the absence of relative movement other than bloom is the worst possible kind of thing to try to see. We KNOW we miss most of the possible targets. Why can't we try to do something that would actually benefit most air users?

I am not trying to flame bw or anybody else, by the way (except CAA, who deserve it) - that post was just symptomatic of many from the Mode S/TCAS lobby. If I die, like the glider pilot who got hit from behind by a Rockwell Commander, I won't be able to say God bless TCAS. I'd rather not die, and be able to say thank goodness somebody finally got some sense and let us all have an effective aid to collision avoidance.

Chris N.

chrisN

21st Sep 2006, 11:16

Robin, have you got room for both a Mode S and a Zaon XRX? I don't.

Bw, have you read the reports of false positives and missed actuals that seem to afflict these detectors? Have you read the reports of Flarm detection rates, and of the algorithms to cope with thermalling gliders, which seem to me to be much better? Why is CAA not studying these reports and forming an informed, not prejudiced, view?

Why do I bother? Don't think I will any more.

Chris N.

robin

21st Sep 2006, 11:31

Hi Chris

No I don't have room for both, neither do I have the power supply for that.

A friend fitted the £300 PCAS (the one with the coloured LEDs) and unless you are able to run it off the aircraft electrics, the battery life is tiny. Certainly not good enough for one of your epic flights - I remember seeing you after an 11 hour trip!!!

Back along we had a visit from reps of the CAA and although most were active pilots, it was fairly obvious that they had little knowledge of gliding or PFA/microlight flying.

As a result they kept on about flying under a radar service at all times, the use of TCAS and transponders, and failed to understand that 90% of the 100 pilot had none of the required kit.

It would be so good if we had someone from our end of the aviation spectrum in a role within CAA to evaluate any proposal before it gets out for consultation ie before it is too far gone to change.

ShyTorque

21st Sep 2006, 13:59

So the pilots of less well equipped aircraft complain that the well equipped aircraft are not looking out of the window, and the pilots with the kit think that pilots without it do not know the rules of the air. What a great world we live in!:ugh:
I have no problem with you guys playing with your toys, but please do not try to make them compulsory. I like flying for fun and the idea of flying a computer leaves me cold. I assume the flight sim enthusiasts are the people who cannot afford to fly fully equipped aircraft.
The PFA and BMAA fleets combined offer about 5000 aircraft without Transponders, most without radio. The BGA will obviously add to this very considerably. Interesting that the number of people who actually fly into each other is so incredibly small. We would add more to flight safety by spending the money on an extra hour a year on stall/spin awareness than on collision avoidance. Perhaps an hour of basic aerobatics for all PPL’s would reduce the fatality’s more than compulsory transponders?
Rod1

Rod1,

I take great exception to you accusing me and others of playing with toys. I fly for a living, every working day and have done since 1977. I by no means play with toys in the air. I'm interested in keeping myself and my passengers alive, not amused.

I justifiably commented that some flyers don't seem to know the rules of the air because if they HAD seen us, they had taken absolutely no effort to avoid a collision when the rules of the air required THEM to give way to an aircraft converging from the right. I had one such incident recently and was forced to take very positive avoiding action on an aircraft that got extremely close, where he should have given right of way. I filed an AIRPROX (don't usually, but this was very close to a mid-air hit). During the ATC follow up the pilot completely and aggressively denied it could have been him because he saw no other aircraft. We were a little surprised he hadn't seen us....... we nearly chewed his starboard wing off with our rotors as he descended across our nose.

robin

21st Sep 2006, 14:20

I justifiably commented that some flyers don't seem to know the rules of the air because if they HAD seen us, they had taken absolutely no effort to avoid a collision when the rules of the air required THEM to give way to an aircraft converging from the right. I had one such incident recently and was forced to take very positive avoiding action on an aircraft that got extremely close, where he should have given right of way. I filed an AIRPROX (don't usually, but this was very close to a mid-air hit). During the ATC follow up the pilot completely and aggressively denied it could have been him because he saw no other aircraft. We were a little surprised he hadn't seen us....... we nearly chewed his starboard wing off with our rotors as he descended across our nose.

Shytorque

I think you are right about the general lack of knowledge of the rules of the air. I assume that even if I have right of way, I'm still going to take early avoiding action, just in case they haven't seen me. In an aircraft the size of mine, I know I'm coming off worst, so I'm not risking my safety by relying on the Rules of the Air.

I do wonder though why it is that some pilots aren't looking out or even thinking about their routing.

An example - flying VFR along a major line feature, I am following the rule that keeps it on my left. I then encounter someone who is obviously following a straight line course between 2 VRPs which takes them on the wrong side of the line feature. My guess is that this person is following a GPS track and is concentrating hard on not deviating from the 'line'.

He might well say that he is flying on instruments OCAS, so he is perfectly entitled to fly the wrong side, but that doesn't help me if I don't take the avoiding action, as he probably isn't looking out that much - if he was, would he not bend his course to the correct side of the line feature?

IO540

21st Sep 2006, 14:33

An example - flying VFR along a major line feature, I am following the rule that keeps it on my left. I then encounter someone who is obviously following a straight line course between 2 VRPs which takes them on the wrong side of the line feature. My guess is that this person is following a GPS track and is concentrating hard on not deviating from the 'line'.

I've got plenty of work to do but this is the kind of comment which requires a reply.

When using a GPS (which clearly Robin you do not and never have, not correctly anyway) one doesn't "concentrate hard" The GPS (unless it is a £100 piece of non-moving-map junk from a camping shop) shows a dotted line which represents your track. It also shows a solid line which represents your pre-programmed route (if you programmed a route; if not it doesn't really matter) and the way you fly the plane is you fly a HEADING which keeps the two lined up.

That's the key to nearly all flying, whether it is VFR, IFR, flying an instrument approach (including an ILS), etc: you are always flying a heading. You don't follow some instrument. You fly a heading, and you PERIODICALLY adjust that heading according to the indication from whatever instrument you use for lateral guidance (VOR, NDB, GPS, even a DME if flying a DME arc).

That is why using a GPS reduces navigation workload so much. You fly a heading, and every few minutes you tweak the heading to keep the GPS track line pointing where you want to go.

I must admit no instructor never taught me this very basic thing, but then I was never taught what the trim really does either. So it doesn't suprise me that so many people think that pilots fly with their nose stuck to a GPS :ugh:

As for following line features as per the book, opinions on this will differ but I don't think many people really care. Let's say I am flying over a motorway, and there is a railway a mile to one side of it, parallel. Which of the two line features should I be following? Same with a coast - you might argue that is a really significant line feature but if it's heavily built-up (which it often is) I don't want to be flying over the houses, especially if there is a strong onshore wind which would make a glide to the beach difficult. Locally to where I live I see countless pilots flying over a town, without being in glide range of anywhere useful. So I wouldn't criticise somebody not following a line feature.

Mariner9

21st Sep 2006, 14:33

When considering which txp to install in my Pioneer, I thought I might as well bite the bullet and install a Mode S. Mode S must be installed by a certified avionics facility. However none of the avionics installation people I spoke to would agree to install anything into a "homemade" wiring loom. (In the event I installed a mode C myself). Dunno how that's gonna be resolved if S becomes compulsory...

One significant negative point for TCAS in GA is the lack of training in it's use. Some of the cheaper GA traffic avoidance gizmo's available do not even give any azimuth &/or altitude indication...WTF is a pilot supposed to do when the units yelling traffic at him that he can't see and has no idea of its location?

Radar (and more recently anti-collision radar) should have prevented any collisions at sea, but it did not, in fact a new phenomenon of "radar-assisted collisions" started to occur. I fear this may also become the case for GA TCAS, unless better technology is introduced, and training is vastly improved.

IO540

21st Sep 2006, 15:20

If the CAA doesn't allow your local avionics shop to install Mode S, then that's a pretty good defence to any requirement to install it, IMHO.

Aviation is a world of anal retention, anal retention, and then some more anal retention. But I must not ridicule it; thousands of jobs and civil service pensions around Europe depend on it.

If it was me, I would just install it myself, in a Permit plane. Save a few hundred quid; more if you can get one from Ebay.

Rod1

21st Sep 2006, 15:26

“Dunno how that's gonna be resolved if S becomes compulsory...”

This was one of the things I looked into for the PFA. You can get some of the transponders direct from the manufacturer and do your own installation. A bigger problem is getting them tested, as some of the organizations would not test a home installation and mode S must be tested at regular intervals (at a cost). All to do with employee liability insurance, or that was the excuse given any way.

I put a second hand mode A in mine and am waiting to see what, if anything, we end up having to fit. I was going to go for a new solid state mode C, but if I had to scrap it in two years it would have been a crazy cost per hour.

Rod1

bookworm

21st Sep 2006, 19:21

(b) If as much effort were put into R&D for Flarm reception by airliners etc. as is being funded for UAV's, Mode S, and other safety or airspace-capacity issues, no doubt Flarm detection range could be improved. There are none so deaf to the possibilities as those who don't want anything but their preconceived (and ill-conceived) part-solution.

I think you're missing the point that I was trying to make in a previous post.

There's a patent application from about 1998 with my name on it for a GA collision avoidance device that works just like Flarm. Somebody has written a letter in the last Flight Safety describing their CDTI invention. I'm sure there are many others, because the solution is obvious. Broadcast your position and receive the position of other aircraft.

I abandoned that application because it was pretty clear that the key issue in this area was one of interoperability and standardisation. It's no good to anyone if everyone is using different devices that don't talk to each other. And there were emerging standards -- I'd hoped that VDL Mode 4 would win, but the FAA threw it out early and at thaat point it was doomed. And the choice of protocol doesn't make much difference to the performance: the power consumption is determined by the range requirement, the cost is determined by the development and certification cost split across the market.

You can beef up Flarm to higher powers if you want, but all you have then is an incompatible device that draws the same power as a 1090ES ADS-B link of similar performance. Operating at the same power, there's nothing fundamentally more difficult about making a 1090ES datalink (that incidentally responds to Mode S interrogations) than Flarm. It's just a box of electronics.

The difference with 1090ES is that it will be carried by the vast majority of powered aircraft.

I'd hope that anyone developing a CDTI device based on 1090ES would learn from all the prior art, including Flarm, TCAS and the alleged failings of the somewhat rudimentary detectors currently on the market.

CAA's proposals for a slightly more practical LAST/LPST have not been adopted by ICAO or anybody else.

The LAST is a EUROCAE standard ED-115.

chrisN

21st Sep 2006, 21:42

Bw, I did not know - or had forgotten if I have seen it before - that the LAST is a EUROCAE standard ED-115; what does it mean - that a 20w or 30w LAST can now legally be used in Europe generally, and specifically in the UK? If not, what other steps does a regulation/specification/standard have to go through to enable people to voluntarily fit it (always assuming they can solve the certification and installation issues)? (I'm still trying to learn about these things.)

By the way, AIUI, Flarm is a de facto standard for gliders flying in the Alps, in certain competitions in some parts of the world, and there is an increasing take up elsewhere. I have not heard of any other approaches having anything like that take up rate.

Chris N

Rod1

22nd Sep 2006, 07:52

According to the PFA the minimum output in accordance with international standards is 70w which is too much for a truly portable device. It is also expected that a 30w unit with an integral aerial sat on the passenger seat of a typical PFA type aircraft will be totally invisible in some directions, and almost so in others. There was a plan to test this as opposed to relying on the calculations but I am not sure how far this has got.

Rod1

bookworm

22nd Sep 2006, 10:56

Bw, I did not know - or had forgotten if I have seen it before - that the LAST is a EUROCAE standard ED-115; what does it mean - that a 20w or 30w LAST can now legally be used in Europe generally, and specifically in the UK?

No, I don't think so, not where a requirement for Mode S exists. Your point about certification still stands -- we need to make sure that the market is at least Europe-wide. AFAIK, the LPST (as opposed to the LAST) is not yet standardised and certified and it clearly needs to be. But I don't see any reasons for pessimism.

By the way, AIUI, Flarm is a de facto standard for gliders flying in the Alps, in certain competitions in some parts of the world, and there is an increasing take up elsewhere. I have not heard of any other approaches having anything like that take up rate.

Dare I mention TCAS? ;)

chrisN

22nd Sep 2006, 13:36

Bw, you can mention TCAS by all means. I would mention it, as in it's take up rate in gliders and light GA is nil. We can't fit it in gliders AFAIK, nor most other light GA, and it would have done nothing to help prevent glider/glider and glider/obstacle (e.g. cable) collisions in the Alps where Flarm started, whereas such collisions have now almost or entirely ceased. Flarm is now used also by rescue helicopters and maybe other things too. As posted by a friend of mine elsewhere (Bill Dean):

"Flarm is, Flarm to Flarm. Up to now it is mainly fitted to gliders,
practically universal in the European Alps, and widely fitted in Australia.
In the Swiss Alps it is also fitted to rescue helicopters, partly because of
its obstacle database.

"ADS-B out can be read by ADS-B in.

"In Australia they are working on the idea that an enhancement to ADS-B
could enable it to read Flarm, and an enhancement to Flarm could enable it
to read ADS-B.

"This is why things may improve when Mode A/C and Mode S are phased out in favour of ADS-B.

"In Australia Flarm is built under licence (OzFlarm), there are other
licensees. Is there nobody interested in doing this in the USA ? It
would surely be ideal for any light aircraft. I understand that there is
an add-on to Flarm which can sound a signal in headphones.

"Remember, Modes A/C and S are only transmitted when the Transponder is
triggered by an interrogation. Flarm and ADS-B transmit regularly without
having to be triggered."

(If any one is interested in Flarm, see http://www.flarm.net/index_en.html .)

Chris N.

bookworm

22nd Sep 2006, 13:55

"In Australia they are working on the idea that an enhancement to ADS-B could enable it to read Flarm, and an enhancement to Flarm could enable it to read ADS-B.

That would be interesting. Are we talking 1090ES-based ADS-B? I presume so, since I think that's the Oz choice for ADS-B datalink.

"Remember, Modes A/C and S are only transmitted when the Transponder is triggered by an interrogation. Flarm and ADS-B transmit regularly without having to be triggered."

This is true, and is why any Mode S mandate should require ADS-B compatible kit. The GTX330, Kinetic LAST/LPST and (I think) the Filser TRT800 all fall into that category. The Kinetic one even has an integral GPS.