Fairly obviously a plane joining crosswind at the right place is not going to collide with a plane which is departing in accordance with normal procedures (and a climb to 1100ft at the numbers is definitely not "normal procedures"; if you are into aerobatics then you do them well away from an airport unless pre-arranged).
Local reports (which could be wrong) suggest that the collision took place after the RV had departed and turned east, either to depart to the east or to fly a circuit. At this point the two converged into close proximity (which is why some early eye witness reports, in the papers, spoke of two planes flying in an apparent formation) and the DA40 prop cut off the tail of the RV6, rendering it uncontrollable except for some roll capability which would not have been relevant to its trajectory.
It is obvious that the location of the prop (on Shoreham beach) is nowhere near the crosswind point for 20. I don't know if that is relevant in this case, but I have seen many pilots joining "crosswind" at the same time as I am doing so, but when I (being over the numbers) have finally found them it turns out they are way out over the beach, which puts them at risk from another plane departing on 20 with a high rate of climb whose pilot, being at Vx or so, is not going to have much (or any) forward visibility. And I don't think a prop that's been ripped out of the gearbox is going to fly laterally on its own very far...
When I depart on 20 I cross the beach at about 500ft, which should be safe, but what if somebody is joining "crosswind" a mile offshore? People have done that too. Such a pilot is likely to collide with somebody who has departed and has turned east and is climbing.
If the DA40 lost its prop over the numbers then a deadstick landing ought to have been easy. If the DA40 lost its prop over the beach (as appears to be the case) then making it back is also consistent with them being at say 1100ft. What would not be consistent is e.g. the DA40 losing its prop over the beach at the sort of height most people reach when departing, at that point, which is only a few hundred feet.
The winds were very light so not really helping somebody to do a rapid climb:
METAR EGKA 041450Z 20005KT 9999 FEW040 18/12 Q1017
METAR EGKA 041520Z 16004KT 9999 FEW040 18/12 Q1017
METAR EGKA 041550Z 17005KT CAVOK 19/12 Q1017
METAR EGKA 041620Z 16005KT CAVOK 19/11 Q1017
METAR EGKA 041650Z 18004KT CAVOK 19/10 Q1017
I cannot believe there is any ATC issue here. Once ATC clear you to join crosswind, you are 100% responsible for doing it correctly. They also have no control over departing traffic, how it climbs, where it goes after takeoff, etc.
I think it is important to learn from these things. Waiting for the AAIB report is no good because everybody except those immediately affected will have forgotten about it by then.
Last edited by IO540; 5th July 2011 at 19:56.