421C

“No way. Transponders are the norm in VFR under 5000', not the exception. You do tend to mythologise sport aircraft (gliders, micros etc) as dominating private aviation and I think this simply isn't true.”

The last time I looked at this, which is some time ago, the single engine C of A fleet was about ½ the size of the Micro / LAA / Glider fleet. If you get even lighter then the numbers get even bigger. Do you have more up to date info?

“I understand the issue with gliders”

Good.

“but I am confused about micros and LAA”

I have explained this is very simple terms, so if you can use the search feature you should be ok

“You are always extolling the virtues of these aircraft compared to "spamcans" that will be resigned to history's dustbin. Suddenly a "spamcan" able to carry a transponder and supply it with power becomes a "wonder-ship". Which is it? Are Micros and LAA types able to carry sensible loads and useful avionics, or not?”

I “extol the virtues” of the type of aircraft I fly, which is a modern LAA VLA. It has modern glass which can have all types of collision avoidance interfaced into it and it already has a mode c transponder, navcom, advanced GPS etc and exceptional visibility. This is a type of aircraft, which is growing in number, but it represents a very small % of the total LAA fleet. The vast majority of micros and well over 50% of LAA types do not have a transponder, and even if they did they would also need more kit to detect other aircraft. The CAA has accepted that mandatory transponders will not happen. FLARM is the only tec I know of which could help us all out, but if you would rather carry on as we are, at least acknowledge that some of us are trying to be constructive.:ugh:

Rod1

“FLARM has low power consumption because it transmits at low power and is therefore low range. It costs less than a transponder because it does not meet a certified standard. If you mandate FLARM, and therefore require certification, and increase its power to something more generally useful, you end up with something that is as expensive and power hungry as Mode S.”

Parts of the world mandate PLB’s which, are hand held, battery powered and save lives. FLARM could be done in the same way, is affordable, and would save lives.

OK guys, I give up. I have put my credit card away and will give my canopy an extra polish before I get airborne next.

Rod1
PS perhaps we could get AOPA / LAA to run a course on getting the best from see and avoid. Looks like it will be the only game in town for the foreseeable future.

Alongside the technology discussion, we should also consider what can be done to help aircraft be spotted visually.

It is now being understood that bright aircraft, white in particular, are harder to spot. Such as the RAF tutors involved in the mid air this week.

Whereas darker colours, particularly black, are easier to spot.

Why not paint all aircraft darker colours, to give the eyeball a fighting chance?

...and transmit on a frequency in the ISM band requiring a special receiver to detect? I think not. Mine transmits on 121.5 and 406, like an ELT, so that the SAR aircraft with standard detection equipment can come and get me.

You shouldn't paint composite aircraft dark colours if used in warm climates

No, I based my comment on the mid-air collision risk being related to aircraft actually in the air. Do you have any info on hours flown by the Micro/LAA/Glider fleet?

We all are. The constructive comment some of us are trying to make is that, attractive as FLARM seems to you, it is not a universal solution - simply because it is limited and uncertified and therefore not suitable for many aircraft that operate in uncontrolled airspace, and who already carry Mode C/S.

For example this, thankfully non-fatal, accident, which could have been avoided by the glider pilot turning the transponder on...
mindensoaringclub.com - Glider pilot survives mid-air collision with jet

The fact the CAA's mandatory Mode S was defeated (a good thing) doesn't mean that people shouldn't be (constructively) encouraged to fit Mode C. I still stand by my guess that the majority of hours flown VFR below 5000' are in types that carry Mode C (or S).

FLARM is simply not going to happen, except in bubbles of airspace where users congregate. Fitting Mode C brings benefits to other aircraft and ATC, and you have the option of adding a PCAS box.

I flew with a PCAS unit (XRX) this afternoon, it was its first use by me. I was surprised by how many (non urgent) alerts it warned me of. On my flight to LFAT it was generally quiet once I was above FL55, East of SFD, but nearer Shoreham (returning), below FL45, on my return, it was almost constantly showing other traffic, usually within 1000' vertical and less than 3nm range. Of some concern was that I only spotted two of these visually, these were about where it "said." It must have warned of about 20 - 30 ones which I didn't see, either because I couldn't or did not have time to concentrate on looking for them,

I was squawking mode "S" throughout.

Rich

Are you sure that it wasn't seeing your own transponder? Many other people have reported this, when they have not calibrated it in accordance with it's instructions.

Once calibrated, this problem seems to go away. At least that's the reports that I've heard.

dp

There was indeed a reasonable amount of traffic arround today as might be expected given the good weather. On TAS I was never short of three or four contacts and sometimes quite a few more. I guess I saw two non transponding. You can always tell, when Farnborough is too busy to give a RIS.

It all seems a bit hit or miss...oh my god did I say that.
But seriously I might fit flarm and be hit by someone with mode C. And with mode C fitted I might be hit by someone without a transponder. Or I may hit a glider, or someone not looking out might hit me...etc etc.

Surely there is some hope that the new high intensity LED strobes may increase our chances of see and be seen?

Unfortunately it is.

That is why there is such a storm over it because the authorities are increasingly concerned that emotionally it is difficult to justify aircraft without collision avoidance. God forbid a CAT and light aircraft collide - the press would have a field day. Everyone believes all aircraft are under radar control ALL the time and have TAS.

Those in the know beat the authorites with the "big sky" stick to which the authorities havent got a convincing answer.

FLARM has its advanatges but is just too late on the scene. It will never be widely adopted.

I have changed my view, and now think all flying machines should be fitted with a transponder. Prices have fallen, I dont think weight is any longer an issue, (see my earlier link) and battery portable units are around the corner. However, I accept cost is an issue, although I think you will get a mode S fitted in a homebuilt for less than £2K.

Although PCAS will never be certified, not only does it work but the technology could be developed further, and the cost would fall significantly if there was greater uptake. I could imagine the vast majoirty of light aircraft having a directional PCAS unit for less than £500. This would provide as good as it gets solution for GA and gliders short of a fully certified Skyforce system.

I definitely think something needs to be done. Transponders/TCAS1 (VFR only as I understand it), full blown TCAS2 or FLARM..... there needs to be something to aid the mk1 eyeball. Fitting a fully certified IFR system for Private flying would be prohibitively expensive and would need some form of pilot training. FLARM would be ok if it is as great as it is made out (at what stage would the system become saturated?). TCAS1 is not terribly accurate and requires a visual contact before being able to manouevre to avoid.

But the big issue here is the military. They have been invovled in a significant number of mid airs with civvy machines, but they will never fit FLARM and if they do have mode S they often don't seem to use it. And if they do have fancy target tracking radar, they don't use it for avoiding other aircraft.

The recent collision of two satellites reduces the credibility of the big sky theory somewhat?

Yet given that most GA aircraft don't use TCAS and we are told we don't see most of the other aircraft flying nearby, the number of mid-air collisions are surprisingly few. Not really surprising as the chances of another aircraft flying in another light aircraft's path within 10 or so feet of the same altitude outside of an ATZ must be statistically very small. (Why are encouraged at as students to fly cross-country at only 2000 feet?)

I recently tried an experiment on FS using FS Recorder Module which allows one to replay multiple previous flights simultaneously with the current one. I arranged for up to 20 "Cessnas" to fly up and down at lease twice at 2000 feet over a 5 mile stretch motorway having taking off at 15 second or so intervals. Although some of the aircraft came alarmingly close there were no "collisions" and only occasional avoidance manoeuvring was required.

On the other hand, if TCAS is available and it helps to give vital information, why are we not all using it? If it was a legal requirement to have one then all the rental aircraft would have them fitted. Most if not all already have transponders.

Reverse engineering - everyone has been told for so long NOT to fly at 2,000 feet that you are now better doing so because no one else is. :confused:

Who knows?

Perhaps we need a survey - who does / does not fly at 2,000 feet?

The 5 or 6 digit price tag? Or do you mean passive systems like PCAS?

I meant PCAS.

By the way, I see the cheap XRX unit has velcro stick-on mounts. How well does this work when having to mount on different aircraft?

Also when working with a LARS - is PCAS going to give you any information that the FIS is not going to give you anyway?

I think the short answer is that the collision risk is only at low levels, say below 1500ft, but

- many of these people are nontransponding (can't or deliberately won't)

- in the circuit, any form of TCAS is not as useful as it could be anyway

If one flies just a bit higher than the UK GA average, the traffic density is very low and it gets very hard to justify the cost of the fitted system (above £10k) and the portable gadgets are messy because for legal reasons they have to appear to be temporary (removable) installations.

“No, I based my comment on the mid-air collision risk being related to aircraft actually in the air. Do you have any info on hours flown by the Micro/LAA/Glider fleet?”

On a poor day, mid week, you are right, most aircraft will have transponders. On a good Saturday in June I would guess the balance would be at least 3 non to 1 with. If hours at my strip v local licensed airfield are typical then LAA / Micros would be flying more than C of A machines. The exception would be the 1% IFR guys who would manage a lot of hours but are very few in number.

If we want a GA/GA anti collision system right now we can have;

A Transponder with a LARS service (IF you can fit it £1600 - £5000 to fit)

Most of the UK is a LARS free zone at the weekends, which is when most GA flying takes place. A Transponder on its own has no GA/GA collision avoidance benefit, as PCAS equipment is not at all common. If we could get everyone a RIS at the W/E this would be an interesting option. Many aircraft cannot fit a Transponder for legal or technical reasons, a fact now accepted by the CAA.

A Transponder and a PCAS (IF you can fit it £2600 - £6000)

This will detect others with transponders. I would think that in the area around say Biggin, you would have a high % of transponding traffic, in the location I fly I consider 80% non transponder equipped at the weekend, which is when I do most of my 90 hours a year. Many aircraft cannot fit a Transponder for legal or technical reasons, a fact now accepted by the CAA

A FLARM system (£500)

(average value of a micro / LAA aircraft is around £10,000)

This would require GA to carry a portable battery powered unit, which can be used in all GA aircraft. No certification issues as it is totally portable.

Now lets look at what will actually happen in practice. Nothing at all! The CAA are not going to revisit the transponder issue as after many years it has realised it is not possible to get what it wanted. The “heavy” end of GA has invested in Mode S and will not accept a simple low cost solution. The “light” end of GA can only go FLARM, and will not do that unless there is a realistic chance of it reaching critical mass. Better brush up on you see and avoid, it is the only game in town for the time being

Rod1

I think that is a little widesweeping, although I understand "where you are coming from".

Although I use TAS most of the time (which is hellishly expensive) I also have used PCAS for many hundreds of hours. In reality both "see" a lot of aircraft that you would not see with mark 1 eyes.

In fact whilst I note your view on the ratio of transponding to non transponding traffic I am constantly surprised how little traffic is reported when receiving a RIS that is not apparent on TAS. Perhaps, as you suggest, the ratio changes dramatically at the weekend and is dependant where you fly.

Never the less combine your eyes with PCAS or TAS and you have a better chance of avoiding other aircraft. Moreover, the nearest collision I had was between me (in a twin) and another twin. At these speeds the time to see and avoid becomes unpleasantly short, BUT the faster the traffic the more likely it WILL be transponding. The threat (to some degree) is proportional to speed.

In short, do not dismiss safety aids of this sort so readily. they may not be a panacea, but I believe they are a significant aid.

Hardly. It is simply that when I have a Mode S transponder installed (and it was obvious c. 2005 - FOUR years ago - that this battle was lost for anybody actually going anywhere for real in Europe) which cost me £2500, minus the $1500 I got for the old Mode C unit on U.S. Ebay, I am not going to have yet another gizmo in the cockpit stuck to the dash with a piece of self adhesive velcro, with the power lead dangling across the instrument panel down to the cigar lighter socket, which I have to push in every 5 minutes (because cigar lighter plugs are pretty crap and work loose) and if I fly above about 1500ft then I am statistically speaking higher than almost any mid-air in recent decades.

IO540

you know I hate trailing wires as well but the cheaper PCAS runs of two self contained AA batteries and the whole unit is about the size of a big matchbox. It is hardly a nuisance on the glare shield. True, you do have to replace the batteries every four hours but that is not the end of the world.

The more expensive unit does require an external power source but if you will, replace the cigarette lighter connector with a BNC and wire a fused supply into the top of the panel - technically removable and not a risk in any event.

oh dear, we are in a mess!!!!!!!:ugh:

The smaller one doesn't give azimuth info, which is IMHO as much use as a chocolate teapot :)

One could climb/descend I suppose...

why?

we did this subject to death a few months ago.

I can understand why you would say that, but I dont agree. Have you tried it?

You will get an alert at five miles, and a seperation level. A thousand feet above or below and its not a threat. However, if it is at the same level keep out an even more careful eye. If the traffic is a significant threat the distance will close - at MOST GA speeds, even head on, not too quickly. Within one mile, you will get an urgent alert - my that concentrates the mind, particularly when, as is quite frequently the case, you STILL have not spotted the traffic. You may well have elected before to have built in some vertical seperation. In fact in some ways the azimuth information can be a distraction. Without azimuth you fall back on a 180 scan, never forgetting that something else might be closing from the other azimuth that is not transponding.

All I can add is that I have used the "system" for hundreds of hours. I have not yet had an urgent alert without eventually seeing the traffic and my vertical seperation has always ensured there wasnt a risk of collision. I know there is an inherant risk that TAS in any form is not completely accuraye in either veritcal or horizontal reporting but I feel a great deal happier with it than without it.

If you havent tried it, it is well worth a go, you have very little to loose with the cheap as chips unit and perhaps something to gain.

It is worth a thought that it almost certainly will never happen to you, but it has only got to happen once. In a few thousand hours I have had three that were close and one way way to close for comfort.

Wow, I am genuinely shocked by some of the replies on this thread, many of which appear to be complacent as to the limitiations of see and avoid, if not completely deluded. My lookout is excellent (!) but I am fully aware of how inadequate it is - airframe blanking, time inevitably consumed by in-cockpit tasks, inability to look in more than one direction at once, empty-field myopia, lack of relative movement against constant-bearing traffic, etc, mean that it is impossible to reliably detect all possible conflicts. Fact.

Anything that assists you in this critical task has to be taken seriously, such as the economic use of the radio to gain SA on local traffic, for example. I have only just learned about these PCAS devices but I am amazed that there is so much ill-informed comment and reluctance to even try it! The MRX model looks like an absolute no-brainer for the cost - even without azimuth, what a great cue to STOP whatever else you are doing and look out NOW! Even it it only alerts you to squawking traffic, at least you can look for that traffic and, having found it and/or resolved any conflict, continue looking for other traffic with a better mental model of the airspace around you. With good, 3D situation awareness (asking a lot, I know), you can even reslove conflicts without seeing the traffic - you can only have a mid-air at YOUR altitude! As to being an in-cockpit distraction, what rubbish - no more so than the altimeter!

Flying IS inherently dangerous AND it is terribly unforgiving of any carelessness, incapacity or neglect.

...with apologies to Captain A. G. Lamplugh!

I just spoke to the main reseller in the UK for this kit. The numbers sold since 2006 are very small indeed, with a 1/3 (smaller one) 2/3 split. We are talking about 278 units!!! Plans to develop a panel mounted version have been recently abandoned, so perhaps the idea has come and failed?

Rod1

I bought a XRX a few months ago and finally had a chance last weekend to take it for a cross country flight. On my way back home, my second to last waypoint, was over a smaller uncontrolled airfield. I was in a low wing plane, cruising at 3000 inside and talking to the TMA controller.

A mile or two before crossing over the small airfield, my PCAS made a small blip and displayed traffic 12 o'clock and -2500 below. The traffic was right below my nose, probably just took off from the field. There was no way for me to see it with my eyes because it was below me but the Zaon was telling it was there. It then showed it climbing up to 1300 feet or -1700 relative to my altitude but parallel to my direction. It was persistently right below me.

We continued forward and about 5 miles further the TMA controller told me to descend to 2000 and that there was VFR traffic below me, a mile to my right at 2 o'clock. I tried looking but just couldnt spot the bugger, the PCAS was showing it but my eyes were not picking it up. This got me nervous so I did a 45 degree bank to the left and made ample room between the two of us. After this I was able to spot him below my right wing, it was a high wing Cessna. He was flying in uncontrolled airspace, below me to my right, and probably completely oblivious to my presence above him.

We were able to keep visual separation all the way home but it got me thinking. If I hadnt had the PCAS, I would not have known of him until the controller told me about it. The controller did not say the direction of flight for my traffic, so I wouldnt had a clue if the traffic was still there a few moments later. The controller told me to descend, practically straight towards the traffic. Again, I was in a low wing, the other guy was in a high wing. At that moment, I was happy to have the PCAS, I knew it was paying back the investment in a very meaningful way. The Zaon does not relieve you from doing a proper scan, but in situations like these, its a priceless tool.

I flew, this afternoon. The weather wasn't particularly great but I wanted to test my new EFIS module (electronic AI, for backup purposes), the conditions were good enough though, for my abilities.

As per normal, I had the PCAS unit running. On the return to Shoreham (from the SFD area) it picked up several transponding a/c, most of which I was then able to locate visually, based on its information. I suspect that without it I may have not seen many of them (due to not knowing where / when to look). The local visibilty was variable but generally poor at the time.


One part of the flight concerned me though. After leaving Shm, on an Eastern track (for SFD), an a/c passed me about 100ft (barely) below on a reciprocal heading. The PCAS picked up nothing (before or after), suggesting that the other a/c was not transponding. It was a reasonably sized 4 seater a/c.

I find it a bit irritating that such an a/c which could probably have been able to squark mode "C" did not do so???

Hmm

Don't bite me but there are any numbers of reasons why you didn't pick up a squawk from him and not all would be due to an inconsiderate pilot.

What irritates me are people carrying PCAS (a minority of GA pilots) criticising other pilots for not squawking Mode C (a majority of GA pilots).

Yes, it would be nice if everyone did, but the reality is that the majority can't at the moment.

There are two very different groups of pilots not squawking mode-C, those who can't for technical reasons (breaches empty weight, no electric system, etc.) and those who won't for philosophical reason. I have plenty of understanding for the first group and (at the moment) none for the second group.

Is there any reason an aircraft with an electrical system and no empty weight limit should not be squawking Mode C (other than in a close formation or other occasion when instructed by ATC not to squawk mode-c)? With the forced move of the IFR fleet to Mode-S, there must be quite a number of used transponders available and altitude encoding is a few hundred pounds to add to an existing transponder - so money shouldn't be an issue.

mm_flynn

Quite agree.

I've flown recently with 2 other pilot owners. One owns a C172 and the other a PA28.

They have transponders that have problematic Mode C's but are OK in Mode A. As it isn't mandatory to carry one, they consider it is way down their lists of priorities, especially given the bills they have had to pay for the ARC renewals this year.

As mine is going through its annual now, and the bills are stacking up nicely, my plan to upgrade my radios has just been abandoned.

robin, I guess the point I was trying to make (maybe not sufficiently clearly) was that the reciprocal direction traffic was of a type that would be expected to have a decent (ie mode C) transponder. As you say though (and so does mm_flynn) this may have been an unreasonable assumption, in its own right. That said,I do get the impression that there are a sizeable (minority) of pilots that don't use "C" if it is not mandatory, I think that this is a shame as it is a level of (potential) protection wasted.

As for PCAS and related equipment, I think this is a bit of a controversial topic not least because the earlier units were not so good. However I find my present unit very good (ZAON XRS) – it often detects traffic I never get to see but are subsequently able to verify that the traffic actually does exist from the radio conversations. I certainly would not ignore a warning from it.

(Slight) change of subject: With the availability of lightweight, high power density Li batteries (I use some myself which weigh a few 100's grammes and provide around 100Wh), how valid really is the argument that some a/c cannot use a transponder due to no elec' system? I stand to be corrected but I seem to recall that the average input power into a transponder is less than 20W...

I agree that technology is making the issue of transponder carriage easier.

But gliders would have difficulty in powering a tx for a 4 hour flight, microlights, similar. Add to that the Mode A equipped C172s/PA28s etc or those where the transponder output is weak and given the numbers of these aircraft which may total around 10,000 of the 20-odd-k GA craft expecting transponder-equipped aircraft to alert you on your PCAS is playing Russian Roulette.

So you PCAS-equipped owners, don't whinge at people disappearing under your wings without warning - you can expect over 50% of traffic not to alert your expensive PCAS/TCAS. You can even hit squawking traffic.

That happened to me a few weeks back in the Elstree 'circuit'. A PA28R routing from Stapleford towards Wycombe came straight at me. Although I was squawking Mode C and had right of way, he never made the slightest attempt to change course, Sitting there in bovine mode he didn't even notice my flashing my lights or my diving out of his way.

Being on Elstree's frequency I was positioning for arrival at Elstree. He was clipping the ATZ and probably on Farnborough North's frequency (or listening to his iPod).

Having a PCAS or squawking perhaps can give a false sense of security.

So for your own (and our) safety, please look out the window from time to time.....;)

A good video review
 

A good video review. Off to buy a MRX.


:D

A blast from the past...
 

I see that this thread is still going.

To those that think their lookout is unassailable, read this Accident Report - a redacted version of the full report is available online here:

[ARCHIVED CONTENT] Page not found
(it is there - no idea why this error message appears?)

Part 1.4 of the report (Findings) includes Human Factors and, specifically, addresses the ability to ‘see’ at paragraph 2. b. For convenience, this link will take you directly to Part 1.4:

http://www.mod.uk/NR/rdonlyres/2BE26...4_Findings.pdf

Incidentally, since my last post I have flown many sorties with the MRX - it is invaluable. Not infallible, but invaluable nevertheless. Buy a TCAS. I don't care which one, but if you are serious about aviation and safety then you cannot possibly overlook the contribution that these make to safety.

The MRX is already integrating with the iPad with one software and showing graphical TCAS targets. Expect more to include this feature soon. Until it's integrated with Foreflight, I will hold off. I want a graphical display, not numbers. It's a bit like having the early GPS's that gives you lat and long only. Not very practical.

More and more GA aeroplanes are being fitted with glass cockpits now but there doesn't seem to be much on the market that enables traffic.
Why is this?

I use re chargeable lithium ion batteries and get at least 4 to 5 hours from the MRX...


http://img32.imageshack.us/img32/954...0330122817.jpg

“More and more GA aeroplanes are being fitted with glass cockpits now but there doesn't seem to be much on the market that enables traffic.”

Pcas
Flarm
Power Flarm
TM250 Traffic Monitor
Gerrecht ADS-B + Flarm
Trig TA60

Three tecs, some of which are combined into single unit. ADS-B, transponder detection and Flarm. If you do a search this has been covered more recently than this thread. If you have a copy of my article in Flyer some time ago it also covers a test of PCAS, Flarm and talks about ADS-B. There will be an update to this in a few months.

A recent analysis of collisions going back 37 years showed that the risk in the cruse was quite low but the risk joining for a busy fly in are much more significant. A screen display showing 37 threats is probably of little value, but a device saying this aircraft is predicted to hit you in 19sec probably is.

Rod1