[ventus45]

P7,

I think that the "elephant", which "caused" the initial speed excursions, was simply mountain wave.

In the image below, note the winds.
50 knots @ 10,000 ft (700hpa) and 30 knots at 5,000 ft (850hpa) out of the WNW over the average 3,500 to 4,000 foot high ranges west of Sydney = bumpy, with a capital "B".



PS: Is "K" going to publish his 4 page list of questions ?

And that tailplane does appear to be "twisted" ?