Originally Posted by
Warped Factor
The current interpretation agreed with CAA/SRG that we're working to is less than 5nm and/or 5,000ft with the absolute proviso that the returns do not touch.
How did the CAA decide that when a mode C is in error, it will always be in error by 4000ft or less within this airspace but by 2000ft or less in other places?
How often has any pilot or ATC seen a corrupt mode C. Not incorrect altimeter setting but corrupt mode C?
Of the two cases I have seen, both were indicating FL300+ when flying below 3000ft.
One can not claim a loss of separation in class D between VFR and IFR because the standard separation is simply do not collide by looking out your window and spotting the traffic! It may be an airprox but not a loss of ATC separation. Where a VFR flight infringes then the atc unit may not notice and may not pass traffic information. Traffic information is to be passed to IFR flights on relevant VFR flights. Now if the traffic info is not passed by a procedural unit then hey what do you expect. However, if a radar unit fails to pass traffic information on what they see then they have failed to provide the required service and any subsequent airporx is not simply pilot error.
Of course, UK VMC minima contrary to the ICAO standard permits VFR flight at the cloud base in class D. Not much chance for the IFR flight to spot the traffic just as it becomes visual then!
As I said previously, it is the system and the answer is not as simple as the pilots being at fault. Until the complete system is tackled then safety will continue to suffer.
Regards,
DFC