I see the bar is still open
That bulletin is interesting for between the line reading. It is a taken that the AAIB are competent, but even that must be tested.
Now we still do not not know
why events occurred but these AAIB comments nudge my eyebrow, partly in understanding and partly in some worry-some thought.
He held a valid Display Authorisation (DA), issued by the UK CAA, to
display the Hawker Hunter to a minimum height of 100 ft during flypasts and 500 ft during Standard 3 category aerobatic manoeuvres.
The 100'/500' minima are normal in DAs and as this was a vertical manouver, the pilot would expect to reach gate height for a vertical recovery by 500' .
I am not sure I wholly agree with the AAIB stating
executing a Derry turn to the left and then commenced a descending left turn to 200 ft amsl, approaching the display line at an angle
of about 45º
My eyeball on the day [from a ringside 400m] and review of video footage with an Ordnance Survey map would have suggested he approached broadly on the A Axis and rolled off it. The crash is 45 degree of axis so he cannot have started at 45 degrees - seemples! But that is nit picking.
OTOH it but causes me to temper my interpretation of AAIB facts with a healthy pinch of salt a this time. Even AAIB can be guilty of some mild speculation.
A manoeuvre of change of axis [from some degree off A axis to a greater number of degrees off it is complicated by the 1000' restriction over the residential area to the West of the airfield.
It creates both a temptation and a requirement to 'keep it tight'.
From the pilot’s electronic logbook, it was established that the pilot had flown a total of 40.25 hours in the Hunter since 26 May 2011,
That being 10 hours per year. That, to my mind, may not affect the competency of an individual to both fly and low level aerobat the a/c, but it may affect future DA issues when viewed in the context a planned aerobatic display for the public.
An analysis of the information using photogrammetry techniques will be undertaken to establish the parameters of the aircraft manoeuvres, including flight path and speed.
In other words they have yet undertaken an analysis of flight path and speed. Interesting ... or they have but the outcome needs double and triple checking before they go hard.
The maximum altitude recorded during the final manoeuvre was 2,600 ft amsl (recorded by Heathrow radar),
and
Initial findings indicate that the minimum air speed of the aircraft was approximately 100 KIAS whilst inverted at the top of the manoeuvre.
Now AAIB would not state this if they were not sure as sure can be - so we may assume these are facts which would pass for government work.
So your homework for this week Bloggs:
Let's talk about that old aerodynamic monkey, the stall.
In particular an stall while inverted at a nudge under 3000'. With 10 seconds to sort it out.
Here's the pen, there's the marker board, you draw it. I'm off for a coffee.