Originally Posted by
Spin Buster
Thank you mm flynn for pointing me at the FLYONTRACK web site.
It appears that around 98% of NATS reported Airspace infringements are not "serious".
Is reporting them a good use of ATC time?
There is no detailed analysis of the "serious" ones.
Are they all GA pilots? Are they without transponders?
What common factors are there to these "serious" infringement?
Does anyone know where the detailed analysis can be found please?
Flyontrack makes a big thing of the cost of 747's having to go around as a result of Infringements but there are no statistics given for 747 go arounds in these circumstances.
Anyone know how many of these there are per year and how the cost compares with ATC holding delays on the ground and in the air?
I can see one of the LHR holds from my garden and it is in regular use. I can't see the go arounds so cannot comment.
Regards
Spinbuster
I did an analysis of a years worth of serious ones (SSE1 and SSE2) and the results are what you probably would expect.
- Mostly GA and a bit of MIL are the perpetrators.
- 1/3 mode C/S, 1/3 Mode A, 1/3 non-transponding.
- The Mode A only/Non-transponder were either lost, thought they knew were they were but were wrong, or just chose to fly through the airspace (a para- glider in Southampton comes to mind)
- The mode C ones where generally more complex. A couple of 'emergencies' and some foreign pilots (ie. not based in the UK) not understanding the UK system.
The mode C/S ones give good notice of the impending screwup so while they might disrupt flights they generally can be vectored around. It is only if they suddenly do something unexpected that you get an SSE1/2 (i.e. a close shave).
To some of your other questions. Yes it is a good use of time to record all infringements, it is a standard safety management approach to look at the minor events to track if your action plan is reducing the risks of a rare major event.
The scale of time wasted and fuel burned from infringements is going to be small relative to that driven by weather and inadequate runway capacity. But that still doesn't mean it isn't a relevant way of thinking of the impact.
And finally, to put it into proportion, infringements caused about 1/3 of the total serious losses of separation incidents. Level busts was I believe the single biggest issue. Which is why the CAT guys get a constant stream of 'must do better' around compliance with clearances and why the downlink of altitude preselect information on Mode S Enhanced was the first bit to be implemented by NATS.
PS - the 5% that were 'of concern' really are of concern. If a controller allowed to aircraft he was controlling to get that close there would be much paper and probably some retraining at a minimum. The fact this happens with one aircraft that is operating pretty much at random makes it a much more worrying issue for everyone. On top of this the 2% or of close shaves really are very worrying events.