Two of the most recent circuit mid-airs in the UK was at a full ATC unit.
https://www.gov.uk/aaib-reports/vans-rv-6a-g-rvgc-and-da-40d-diamond-star-g-cezr-4-july-2011
https://www.gov.uk/aaib-reports/8-2010-g-eyes-and-g-bolz-17-august-2008
Indeed, and lots of people have views on both of those which don’t exactly get reflected in the accident reports i.e.
) is a total free-for-all in the legal sense and some sectors of the GA community really do believe in thatIf I do a post-maintenance flight where I want to avoid ending up over the sea, I will tell ATC that I will do an early left turn “which will conflict with crosswind traffic”.
Peter wrote:
if somebody does something crazy, like climbing up rapidly to reach circuit height around the crosswind join point, they are likely to hit somebody
The only reason it’s “crazy” is because traffic is crossing his path in a completely inappropriate place. Otherwise using all the climb performance available is the safest and best procedure. A friend who finished his RV-3 this year has been experimenting with propellers recently and tells me he can now climb from the deck at close to 3000 fpm…and he does. Often by the time he turns off runway heading he’s climbed above the Class D 
Peter wrote:
I do a post-maintenance flight where I want to avoid ending up over the sea, I will tell ATC that I will do an early left turn “which will conflict with crosswind traffic”.
We just add “early right turnout” to the request for takeoff (meaning a right turn at say 50ft height) and fly under the downwind at mid-field. This is not necessarily the safest thing, overflying a totally built up area at low height, but it’s fun and gets us on track quickly.
That would suggest you don’t have crosswind joins there. Actually I am not sure how common they are in non-UK Europe; I have not heard the term elsewhere but then I have not done much VFR outside the UK.
We have all types of pattern entry at ATC discretion, they stick you in where it suits them. An early turn out on takeoff would be well before the crosswind leg of a standard traffic pattern, typically between midfield and end of the runway.
Dave_Phillips wrote:
Two of the most recent circuit mid-airs in the UK was at a full ATC unit.
Both seemingly down to ATC misjudgement…probably with the pilots trusting the guy in the tower instead of looking and/or questioning….Ironically, had they been operating at a non-towered field and making multiple position reports, each aircraft would likely have had a better picture of the other’s relative position….IMO….
Peter wrote:
Class G (an ATZ is irrelevant ) is a total free-for-all in the legal senseIn my understanding an ATZ is not at all irrelevant. SERA.8001:
“Air traffic control service shall be provided … (d) to all aerodrome traffic at controlled aerodromes.”
The definition of “aerodrome traffic” is “all traffic on the manoeuvring area of an aerodrome and all aircraft flying in the vicinity of an aero drome. An aircraft operating in the vicinity of an aerodrome includes but is not limited to aircraft entering or leaving an aerodrome traffic circuit”
This holds even in class G. It is another matter that ATC is not obliged to apply the same separation standards as in controlled airspace.
I was under the impression in an ATZ, AT utterances are an instruction, and should therefore be read back and obeyed. In other words if the instruction is to join overhead and descend dead side, that is what you are required to do if you have accepted the instruction.
In theory, AT provides seperation in various ways, (visual and by the joining instructions given) however, in reality, it is difficult to provide absolute seperation because (withour radar) they have no way of confirming that the instructions have been complied with.
Exactly…
It would be a different proposition if ATC was required to suspend takeoffs when there is traffic cleared for crosswind, but that would really mess up capacity on busy days. It is thus a requirement for departing traffic to not climb so steeply.
Peter wrote:
It is thus a requirement for departing traffic to not climb so steeply.
I do think there is a tendency not to take the crosswind instruction strictly. Wide of crosswind and you will be in the potential climb out, depending on high wide and the performance of the departing aircraft. However, taken implicitly, it would either have to be a very long runway or an aircraft with exceptional performance and a very steep rate of climb to intersect the crosswind above the numbers at 1,000 feet or more of a typical circuit. However, you would also be irresponsible to make a max. performance climb knowing there was any risk of intersecting any have reasonable cross wind join, including one made wide of the numbers. Of course a Pitts or an Extra would be capable of the required performance to name two potential candidates but not most GA types.
