Isnt a further problem than even with a LARS not all targets will be seen on primary. As I understand it gliders do not paint well, as is also the case for some composite ultra lights as originally suggested in this thread.

I appreciate they should not be in IMC but you may be descending through an undercast and there is always the risk the first thing you will meet is a glider very close to the base which is not transponding and not being painted on radar.

Of course there has never been a mid air between two aircraft outside CAS in IMC in the UK so the record is in favour of not meeting another aircraft.

I can think of a number of commercial operators that are public transport that operate outside of CAS and do not carry any form of TCAS. For example there are regular commercial flights from Shoreham to the continent who at best might get a service from Farnborough for a few minutes but are outside their cover over the channel and not within Lilles cover.

IMCr training. I find real cloud very different to foggles, and fly in as much as I can find (instructor willing).

Nigel, you need to do some GA flying :)

In the UK, the easiest way to get about is to stick with Class G. That way, you cannot be refused a transit.

Due diligence means you should obtain a RIS when you can but often you cannot.

Combine that with flying at/above the MSA (avoidance of scud running i.e. CFITs which kill many orders of magnitude more people than mid-airs) and you often end up in IMC.

Objectively, it isn't a risky thing to do because anytime the UK weather is naff GA is very thin on the ground, and GA in IMC is even thinner.

Say I fly from Lydd to St Mawgan. I will try to stick to FL040 and that means I need a transit of Solent. Usually I get this but sometimes not till too late, so I have to dogleg under the airspace at 1900ft.

IMC or no IMC.

Anyway, FL040 is probably in cloud too.

FL060 is not possible due to Class A, and a FL100-FL180 Eurocontrol route needs an IR as well as being a bit of hassle to prepare, and it is guaranteed to place you into icing conditions IF there is IMC at airway levels.

But I am sure you know all this.

Thanks to the "make the IR really hard to keep undesirable characters out of the airlines" policy of past decades, very few private pilots have an IR so cannot get the additional protection of controlled airspace enroute.

And training in real IMC is much better than with foggles.

That is the problem with all things aviation. I don't see why for "VFR use" things like fitting of FLARM, panel mounted GPS's cannot be deregulated, so that anyone with an ounce of common sense can fit the thing themselves?

After one star annual, when leaving the zone our radio failed, despite having just had the radio annual done. I had to fly back home non radio. We investigated it ourselves and found the centre core of the antenna coax had come unsoldered from the back of the radio tray connector. We resoldered it and it has been fine ever since - that was 2+ years ago now.

As for fitting panel mounted gadgets for VFR use I know I can fit one, do all the wiring to a high standard, and for it to be done as well as any avionics shop........

With regards to GPS's - if I replaced our panel mounted GPS with a new one, wired into the same power supply connections and same antenna connections, what paperwork if any would be required?

Nigel and others

I have been giving a little more thought to TCAS and CAS within the GA enviroment. I would be interested in everyones comments.

So, we are agreed the POH says you should visually acquire the traffic BEFORE taking avoiding action. Skywatch, in a similiar way to full TCAS, paints a bubble around the aircraft. In Skywatch's case if an aircraft enters the bubble you will get an audible warning and the display will indicate the height and position of the traffic relative to you, together with the positional trend of the traffic. You do NOT get an RA at any time.

Here is the scenario.

You are en route and not receiving a RIS. Its VMC but 4K. You note on TAS traffic at exactly the same level at a range of 10K which will cross your track line converging at right angles. You are flying at 175knts and the other traffic is at a similiar speed.

What do you do? Do you do anything until you have acquired the traffic visually?

Personally I would slow down to 150knts.

I do plenty ;) but all in Permit aircraft (JPs, RVs and Yaks) so VMC only, and with, by defintion, "low tech" aids / instruments. Rest of flying is airliner, so 99.5% CAS, with the odd RAS outside briefly when circumstances demand.

TCAS doesn't really paint a "bubble"... it is time based, so someone can get quite close, but if assessed as not a collision risk, it says nothing (might show something but can get excluded from the display).... whereas if a potential collision is assessed, it goes TA, and RA when it gets drastic :eek:

Answer depends on how accurately it plots the 3D relaitonship. We all understand the vertical (Mode C), but Range? Bearing? How do these things assess Range? I understood one system to rely on signal strength? But how does this work with different power transponders, and variations in power as, say, the Line-of-Sight might get interrupted by other antenna, gear legs, even wings in a turn etc.? Bearing I think we seem to agree is "indicative" only?

In theory, it would seem "nothing". In practice, it would seem you need to ensure a separation is achieved in excess of the limitations / accuracy of the "system" (system comprising hardware units and user SOPs / ability) i.e. in a simplistic sense, if the "accuracy" of the hardware was, say 95% likely to 2NM, you would want to clear all targets by >2NM. But we'd quickly get into complex maths since I bet it is not a raw "x NM", but a combination of factors... And as stated above, you also need to factor in "what the other target" is? It might be using TCAS on your Mode C - and therefore unknown to you it might have an avoidance strategy completely incompatible to yours? And/or ATC (who at least will be trying for decent amounts of separation)... or someone just dozing along...

Whatever, you and I (and others) have been applying thought to the problem... and it might result in a solution sometime :D

NoD

englisha. I am in total agreement with your last post. All my near misses in the last 20 years have been in VMC whilst trying to maintain the best possible lookout. The reduction of transit space around controlled airspace means one has to spend more time on accuracte navigation, be it by GPS or topo. TCAS systems are a complete was of time against microlights and small flying machines that will never carry such.
I use TCAS in my Day Job and are fully aware how good the system is.

NoP

Range accuracy 0.05nm (typical)

Bearing accuracy 5d rms (typical), 30d peak error

Altitude accuracy +/- 200 feet

from the OM.

NoD, my present job involves flying the private owner of the aircraft; I'll say no more than that.

Yes, bad weather / IMC does reduce the number of aircraft in the sky, sometimes what a welcome relief that brings!

This will possibly sound selfish, but it's not meant to be. From my point of view, the very worst time to fly is in the daytime, in excellent weather, especially at weekends or on bank holidays.

Hordes of low time non-IMC rated pilots who have been waiting for weeks for good weather are trying to get current; they are often thinking more about the physical control of their aircraft, navigation and what they are about to say on the radio than on lookout. Solo students are trundling along on their QXC flights, ditto. The radio workload of the ATC controllers can be exponential at these times, sometimes a meaningful ATC service is unavailable. This forces more aircraft to route round CAS (can't get a timely clearance) making the choke points a very dangerous place to be (Luton's western and eastern ends, for example). A re-route puts many pilots' eyes inside the cockpit, or down to the surface, instead of remaining up front....looking out.

I have had a number of airproxes in my thirty years or so of flying (airmisses as they used to be called), all have occurred in very good weather and in Class G. Aircraft colour contrast is often not good in sunny weather, despite what many might think. For example, a white or partially white aircraft can disapear against the background of mixed cloud. ANY colour of aircaft can be indistinguishable from the mixed backdrop of a town.

TCAS/ Flame discussion
 

I have started a new thread. A little insensitive to continue here. Please contibute your thoughts so we can improve saftey for all.

Was there ever an aaib report produced on this? If so, I seem to have missed it?

I don't believe it's been published as yet

It would seem that the timescale for the release of an AAIB report, when there is a fatality involved, is about 12 months.

Rans6....

Which just reprompts the question about a lack of report from an incident that took place nearly 1 - 3/4 years ago and is very likely to have some material learnings.

sorry, omitted the words "a minimum of" after the word "about"!

It is a bit sad that preliminary info, which may just prevent a similar occurrence, does not come out within the attention span of the flying community at large.

Rans6...

Agree with that - and also it would be good to have a forum representative from the AAIB, as NATS now have.

AAIB report has been published today

Report on the accident between Cessna 402C, G-EYES and Rand KR-2, G-BOLZ, near Coventry Airport on 17 August 2008

RC

Nothing new from the report really - sorry to say, but it was only a matter of time before this happened.

Rest in Peace.

<<but it was only a matter of time before this happened. >>

Just curious but on what grounds do you make that statement? I never worked at Coventry but I did spend a year at Kidlington where that sort of situation arose many times every day.