Gavin Grimmer
Dark Blue Lines Airspace Boundaries
Red Line is 33 nm perimeter away from RP Craven
Yellow is direct route Taree to RP Craven
Green line is plotted course of ZK-MDX
At his Flight Plan GS of 135 kts he should have travelled in the region of 10.25 nm in the 4 ½ mins if he had continued directly on towards Williamtown (direction of green line towards blue Airspace boundary). This would have placed him at 30.5 nm from RP Craven which would have made his ETA for Craven as 09:12, so you can see this is unlikely to be what he did. Apart from the point of busting airspace, (for the sake of this equation) in the event that Mike had not turned towards RP Craven, it would have placed him even closer to RP Craven:
Extended Green Line is Direct Route to Williamtown and about where he would have traveled to in the allotted time (26 nm away from RP Craven)
Red Line 33 nm perimeter away from RP Craven
We know it took them 22 minutes before he believed they were at Reporting Point Craven due to the radio transmissions with VH-ESV – another aircraft that was checking on his position in regards to Craven. For Mike to know so precisely when they were over what he believed was RP Craven indicates that he was about to intersect a radial shown on his VOR instrument. There were three possible radials – Williamtown, West Maitland, and Mount Sandon.
To work out which radial he was heading towards, we need to work back from the first radar paint position that Sydney got of him. VH-ESV told of a westerly wind of 70 knots further north at a higher altitude, so we will do the calculations using wind speeds over a range of 50 to 60 knots. We know the time frame from ‘his Craven’ to the Radar Ident. position was 10.75 minutes (09:17:48 to 09:28:28) and so able to calculate the distance covered. We also know the maximum airspeed (Flight plan) likely to be flown was 160 KTAS. From this information, we can calculate the furthermost distance he could have traveled in this timeframe with these winds.
MDX pg 6
