There will also be no way for one controller (Approach) to know that the Mode C is verified (by Zone for example) unless they pass traffic information and maintain track identity.
Originally Posted by BEagle
So pass the information on then!
BEags -with all due respect. When I am busy, the last thing I would have time for is passing traffic info on to (presumably) all the adjacent radar units, on all the (newly transponding) returns that I
might be giving a service to just in case they
might want to know about it. Conversely, the second last thing I have time for is continually answering a ringing landline from someone asking for traffic info on traffic that I may, or
may not, be working. To suggest otherwise shows that you really need a visit (and beer) to the nearest friendly Scottish Centre methinks.
Originally Posted by BEagle
But spurious or ambiguous TCAS TAs generated against Mode A help no-one - hence I still believe that no-one flying an aeroplane of < 5700 kg under VFR in the 'open FIR' should be compelled to carry a transponder, but if they do, it must have height encoding.
Again the question is posed. How does anyone know that that Mode C, or Mode S height readout is actually verified ? Bear in mind that TCAS can only provide separation based on that vertical info (and not on any azimuth info), what happens if that height readout is wrong ? There have already been intersting TCAS incidents with ac climbing (into) conflicting traffic, because the Mode C was wrong and indicated (wrongly) that the traffic was below when in fact it was above !!
A large increase in the number of transponders will surely lead to a proportionate increase in the number of incorrect height readouts ?
Now, what if EVERYONE who had to have a Mode S installed called up their nearest ATC unit to get it validated EVERY time they went flying - how long before CAA would be issuing safety notices advising people not to do that as it was overloading controllers ....... my guess .... not long. Rather ironic don't you think ?
What also happens if Pilot A inadvertantly has the wrong pressure setting on his altimeter ? Am I right in thinking that TCAS assumes all height readouts are based on 1013mb ? What happens below the transition altitude ?
Although I am still reading through your fine table, I still also disagree strongly about making a transponder compulsory for VFR in Class D - Our club operates quite happily in Class D airspace, using standard entry/exit lanes and procedures, which keep us separated from the IFR approaches and climbouts. A transponder is not mandatory at the moment and (more importantly) experience has shown that it isn't a problem. If it ain't broke don't fix it.
Now, sure, I am pi$$ed off at the prospect of having to shelve out (yet) another wad because of some potential CAA ruling ... I am still reeling from the CAA move on Engine TBO (March 2006). In one bureaucratic pen-stroke my 700/1500hr engine is now declared unfit for flying club rental, because it is over 12 years old - cost to resolve this .. ? £20k !
My anger on Mode S (and the false premise being used to push it) would be abated somewhat if it was being paid for by those who want/demand/benefit financially from it. I also note that in the CAA RIA, they make a meal out of all the costs to GA/Business Aviation.
For all their accountants credentials it is surprising that they fail to point out the quantifiable commercial gains for airlines of making everyone else install Mode S. That is a figure I would like to see. It shouldn't be too difficult for the 'experts' to come up with one. Then perhaps the equation would be less one-sided and more transparent.
I would also like to know who most PPruners think should pay for Mode S?
GA ? Airlines ? Or hypothecated from Govts rip-off tax on Avgas ? Or the CAA/NATS ?