How did they manage to hit each other? Didn’t they get a warning on their alarms? That was a wake up call for many pilots.
I’ve never done gliding but I have been told by glider pilots that gliders routinely fly very close, to get the same updraughts, so I would expect proximity warnings to be disregarded, or even used tactically.
Having been flying with my TAS605 for about 4 years now, I can have a guess at how a traffic warning device might not prevent a collision:
So nowadays I take action at 1nm or so, usually by changing altitude and direction at the same time. Against a Mode A target (about 10-20% of transponding GA in the UK!) I change direction only, but if flying VMC above cloud, say 3000ft+ I might not take any action because I have never seen a non-TXP or Mode A aircraft above cloud (that tells me something 
). So this – disregarding Mode A traffic flying in a highly improbable place – is another way one could have a collision, although the odds must be vastly smaller than at low level.
Also flying in IMC one might have to disregard Mode A traffic, for the same reason: the sort of people who fly Mode A (I mean, they are either so ignorant they don’t know about it, or they are umb enough to be doing it intentionally) are not likely to be comfortable in IMC. Yeah, that assumption is highly dodgy but the UK has never had a midair in IMC, since WW2. But I would still avoid it horizontally if I was OCAS and not going anywhere in particular.
Also, google on “radar assisted collision” and you can see how traffic warning systems can work the wrong way.
Peter_Paul wrote:
hello can you maybe keep me updated with this installation (maybe some pics and links for hardware) as I would like also to expand my PAW for FLARMmany thanks allready now
Will do. Doubt I will get it finished this side of Christmas though. But I will take a pictures of it all when complete.
thanks dont get stressed about it lol
@Balliol
Could you tell us more about the FLARM installation in your training fleet ?
It seemed very neat. I wonder what kind of hardware is involved.
And, as I understand the fleet received both TAS and FLARM, I would be glad to get your feeling about those two systems.
Hi, in the Grob Tutor the FLARM is a behind panel processing unit with two displays – one mounted in front of each pilot on the coaming. It is fed by and upper and lower GPS aerials situated in front of windscreen and rear of lower cowling area. It performs pretty well at giving an alert of where a glider (or other FLARM) traffic threat is – it works on providing visual indications of the nearest traffic and visual/audio warnings for the nearest potential collision threat, i.e. it is not a device to give you a mass situational awareness picture of a large area. LX Avionics website has details of all the kit (I don’t know where ours was sourced from though)
We also have Avidyne TAS600 displaying on Sandel SN3500 EHSI – with upper aerial in front on windscreen and lower aerial on lower rear under fuselage. I find performance to be excellent on this, although you have to remember that the update rate in turns can of course lag.
[disclaimer not an avionics engineer!] However I think a lot of the key to getting these systems working right is good aerial installation and positioning. It is also how about you manage your sortie profile relative to what the systems are telling you – I’ve seen people (not in my operation) blindly ploughing towards a similar level contact, or watching one climb/descend to their level, wasting time trying to visually acquire it rather than getting on with some ‘defensive flying’ and some climb/descent/turn avoidance.
It is also how about you manage your sortie profile relative to what the systems are telling you – I’ve seen people (not in my operation) blindly ploughing towards a similar level contact, or watching one climb/descend to their level, wasting time trying to visually acquire it rather than getting on with some ‘defensive flying’ and some climb/descent/turn avoidance.
That is a really interesting point.
When flying under what used to be called Radar Information Service, now called Traffic Service, UK pilots are trained to try to visually acquire the contact reported to them. This is probably because the information provided is poor e.g. “contact at 3 o’clock, 2 miles, same level” or better still the rather more common “contact at 3 o’clock, 2 miles, altitude unknown” (most likely someone trying to protect their civil liberties 
).
I found myself doing the same with the active TAS/TCAS. Almost as often as with the radar service, one never spots the contact. But by the time one has decided it won’t be spotted, it may be too late…
@Balliol
Would you be able to photograph the FLARM antenna on your training aircraft, next time you have a moment ?
I would be very interested in seeing the placement and type of antennas.
Thank you !
@Balliol
And also, would you have the kindness to picture the rear of the flarm screens ? I wonder how they are attached to the glarshield, and how the cable is running out of them.
Thank you !!
A few things here that I don’t understand first the TX1500A has an authorisation to be fitted to IFR Aircraft, this is for situational awareness and should not ( as with a TCAS RA warning ) be acted apron instantly without question.
Secondly the biggest likelihood of collision comes from gliders, they are very hard to see, usualy don’t talk to radar units and but the very nature of finding lift are constantly turning but most of the gliding community have FLARM. So for a small outlay ( by aviation standards ) you get a box that detects 90% of the problem traffic.
While it is not perfect it does significantly load the dice in my favour.
