Originally Posted by
Chronic Snoozer
It’s the rate of convergence not “speed” that’s the catalyst for damage, which is what Squawk meant I believe.
The rate of vertical closure can be estimated between photos B and D of the third pass, then add the rate of roll.
Even so, if the rate of convergence was 'high' then the probability of severe damage to the other aircraft would also have been high. I do not think it was a large shunt, just very unlucky for the downed aircraft in the mechanism involved and the relative contact points. Obviously there must have been some decent amount of convergence to create the damage, but considering the load on the surviving aircraft was akin to negative load to the spar and structure, it can't have been a big hit. Considering the paint and damage to the surviving aircraft was on the top surface, (whilst inverted) then the wings must have collided, slid against each other then as the contact continued it's ripped part of the leading edge and wing tip downward, to create the damage observed. I'm no expert on it, but just what it looks like to me from the pictures. I suppose the natural reaction would make the situation worse, by wanting to roll away from the other aircraft, which would increase contact.