Originally Posted by Droopystop
I have assumed that this is because there is unreliable or no primary contact. Is that an anomoly to the North Sea?
The North Sea is a big area - any part in particular?
Originally Posted by Fuji Abound
So where a service is being provided by a CAS service provider but continues the service outside of CAS I understand from your reply that they would have primary. For example Gatwick will often provide a service outside of their class D.
Primary will be available - yes
If the provider was unable to provide primary cover would they have to discontinue any service?
Yes again - you'd be limited to a Radar Control Service inside CAS, but a FIS only outside.
Interesting point with regards the military. Presumably working Brize for example you are suggesting they might be providing you with a RIS but without primary cover?
Indeed - but you would be notified on that under the initial "contract" of service.
I am also interested to know how well hot air ballons show up on primary? Gatwick asked me to intercept and identify a ballon a while back but I subsequently wondered how well they were able to "see" it on primary.
Not particularly well, but you can get a faint return. If ATC know there is a balloon in the area however and it hasn't called, then it the info will either come from the tower seeing it or an aircraft sighting, and them passing the information onto radar.