From UIA post on the Yak fatal....
During a tailchase, the aircraft entered an inverted spin at approximately 1,800 ft agl, probably because of unintentional pro-spin positioning of the flying controls. Although the spin ceased after three turns, the aircraft impacted the surface of a lake during the ensuing dive. The investigation identified several factors relevant to the accident, including operation of the aircraft, the type of flight instruments fitted to it and the manner in which the activity was conducted
The aircraft had come to rest submerged in a small lake, approximately 30 metres from the shore. Examination of the wreckage by divers confirmed that the aircraft was lying inverted on the lake bed. The right wing had separated from the fuselage and the left wing had failed approximately eight feet from the wing root. An initial examination of the aircraft was carried out after recovery from the lake. The engine mounting etc.
Both occupants had been wearing parachutes and their harnesses, including the crotch strap, and the rudder pedal foot straps were securely fastened. The damage to the fuselage had resulted in failure of the forward cockpit shoulder harness mounting structure. One section of the mounting bracket for the rear cockpit shoulder harness had failed, releasing the right shoulder harness strap. The left shoulder harness strap had failed approximately 30 cm from its attachment point.
The aircraft impacted the water in a dive following recovery from the inverted spin. Had the same recovery begun at sufficient height, the aircraft would not have impacted the water
In a succinct 15 pages, the 'old enemy' shames the ATSB in so many ways. Lucid, clear logical analysis provided without CASA interference or inference, does not rely on the sterling efforts of the QPS, no embuggerance of evidence, no baffled Coroner, no medical loopholes, no ducking, diving or weaving. Hell even Warbirds didn't get a mention. Just a blessed report: simply and effectively providing most of the answers, as requested and required. Someone send it to ATSBeaker along with a taxi voucher, four white feathers and a self flagellation kit....Please..
Repeat x 100: I will not get cranky on Sunday....I will not - Argh, battle lost.