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boomerangben
19th Jun 2004, 09:41
Has anyone out there parted with hard earned cash and fitted one of those fancy Traffic Scope black boxes that Transair are selling?

Are they any good? And do they only give height and range information or can they give indication of azimuth as well?

bfato
19th Jun 2004, 12:01
Not tried one but seen the advert, browsed their website.

They seem to work by listening out for transponders replying to third party interogation (ATC or TCAS). The strength of the signal received is used to estimate the distance, and the altitude is available if that aircaft is squawking mode C. Since there's no other position information in a transponder transmission, it has no idea of azimuth. It can estimate closing rates based on the rate of increase in signal strength, and can track multiple signals (aircraft). Or it least it can if they are squawking different codes. I don't know how/if it can differentiate between multiple aircraft squawking 7000...

Might be more useful when we all forced to have mode S?

IO540
19th Jun 2004, 13:20
Without azimuth info, you better have a very flexible neck, not to mention an aircraft with 360 degree vision :O

It doesn't take many flights under a radar information service to realise that without azimuth, most warnings will be useless. Even with an RIS one cannot spot most of the traffic mentioned if the visibility conditions are less than great.

On top of that, most PPL flights have no transponder, or have it switched off, often deliberately. This means that you have to maintain practically the same lookout as before.

Personally I would save the money and put it towards a really good top-end GPS, with an external aerial - suction cup job if you cannot get one screwed down on the roof.

Floppy Link
19th Jun 2004, 19:33
yep, got to agree

the best thing about TCAS is that it shows you which direction to look.....without an azimuth display I wouldn't waste my money.

If I had any money... :(
Russell
http://www.espotlight.co.uk/gbtbi/listings/43.jpg

boomerangben
20th Jun 2004, 13:13
Thanks for the replies guys. I'm not in the market to buy one, but a couple of other threads on useful/useless gadgets got me thinking. However it is nice to see technology progressing and maybe before too long, there will be a more useful affordable version of TCAS available to the masses.

PPRuNe Radar
20th Jun 2004, 13:47
the best thing about TCAS is that it shows you which direction to look.....without an azimuth display I wouldn't waste my money.

Within reason, since the azimuth accuracy can be up to 30 degrees out. You may end up looking to the left of the nose when in fact the traffic shown on the TCAS is actually off to the right.

TCAS systems in use (TCAS I and II) do not provide horizontal avoidance advice. TCAS III intended to use the TCAS directional antenna to provide horizontal avoidance but was abandoned by industry as not being good enough for the job due to the bearing inaccuracy mentioned above.

TCAS IV should improve this accuracy by including positional information sent from the target aircraft (encoded from GPS or similar onboard source) and so will also offer horizontal avoidance advice.

G-Foxtrot Oscar 69
20th Jun 2004, 19:19
I was a bit worried that a "budget" low end TCAS could in the GA VFR community cause complacency and lead the user not to look out as much.

I sail a boat with a radar system that has a closing alarm. When I first got the system I used to set the alarm to 0.5NM and closing and drift along letting it do it's job. Well after it had been running for a couple of weeks and worked well I relied on it..............untill a very close shave with the Isle of White hover craft!

Perhaps I am giving a glum opinion of a device that may improve safety and would be interested to see what other people think.

nosewheelfirst
20th Jun 2004, 23:56
The best TCAS for light aircraft under VFR is the Mark1 Human Eyeball.

Its another piece of equipment that will keep pilots heads inside the cockpit and not outside.

I would spend the money on several hours of flying.

Just my two cents worth.

Nosey

Mark 1
21st Jun 2004, 12:52
Thanks for the compliment nosey.

But even my eyesight is not what it used to be.

p.s. I agree that they seem like a waste of money.

Mk 1