While the Civil Aviation Association conducts its inquiry, the aeronautical world is at odds over what went wrong.
On the Avcom.co.za website, top aerobatic pilot Nevillie Ferreia wrote: “The lomcevak went fine at first, but halfway through he changed control inputs. From the ground it appeared as if he tumbled forward then backwards.”
A lomcevak is a family of extreme aerobatic manoeuvres where the plane, with almost no forward speed, rotates on chosen axis due to the gyroscopic precession and torque of the rotating propeller.
“Without any closing of throttle and changing control inputs the tumbles reduce airspeed and he entered an inverted flat spin,” said Ferreia. “At this altitude one to two rotations would be enough, but Glen only closed the throttle after five to six rotations. This is possibly after becoming conscious again from the time of max rotational forces through the tumble. He closed the throttle to recover from the flat spin and needed the power again to pull out of the dive.”
But that didn’t happen and the Dells Extra EA-300 slammed into the ground.
On Flyingmag.com John Comley said: “It was not the ‘normal’ time-to-recover-from-spin or miscalculation of height problem we have so often seen in aerobatics accidents. The calling of Mayday by a pilot as experienced as Glen clearly indicated a mechanical problem, a subject of much debate at this point in time.”
Paulo Iscold disputed on aerobaticsweb.org that Dell had been performing a lomcevak, calling it a tumble. “The spin developed after the second tumble turn … The question is what happened during the two spin turns just after the tumble and why did the throttle come up during the spin recover … Was he out for few seconds?”