Originally Posted by
Lefthanded_Rock_Thrower
Haven't we already looked at this, Page 7, post 126 or there abouts ?, nice picture by the way.
Yes. and thanks
Originally Posted by
Lefthanded_Rock_Thrower
Did not we agree that sometime shortly after 1042am and before the sudden stop, the aircraft did breach the protected areas ?.
Nope... The ATSB report's lowest observed radar altitude is 5100'. I have shown how 5100' could be considered VALID and SAFE by our lovely French piece of engineering.
Originally Posted by
Lefthanded_Rock_Thrower
So what is your point ?, IF in RADAR coverage this aircraft would have made TAAATS MSAW go "BING' at some stage, it might have saved the day.
My point is that exactly the radar coverage that was present on the day would quite possibly NOT have made the machine go BING, despite Dick's (correct) claim that the aircraft was on radar and below the GRID lowest safe of 7000' plus.
Originally Posted by
Lefthanded_Rock_Thrower
Perhaps you could also transpose the actual track of the aircraft as per the ATSB report and zoom in on the last 5 minute of flight ?.
Working on that now, although it's a little hard to do exactly... Certainly from what I see can on the atsb's diagram, that last observed radar paint was within 25NM BLA at 5100' - which is kosher as the 25NM MSA is 5000'. The only question is whether the diversion left of track took him outside the tolerances of the AY-ELW track, within the 25NM MSA WGT of 6300' (or possibly even outside that with the grid of 7100'), and what altitude was observed at the time...
Originally Posted by
Lefthanded_Rock_Thrower
Then comes the ADS-B nay saying, ADS-B will be sending PH (pressure height) data (i.e 1013 mb / 29.92"), whilst this is not on area QNH, neither is Mode C on the SSR, Mode C is also of the same type, if not the exact same PH encoder, do you guys really understand that little about what goes on ?, from my understanding TAAATS then levels all the data with the Area QNH's.
All correct. Transponder sends out PH reference 1013. TAAATS uses QNH feeds from a selection of locations (ML, WG, CB, AY to name a few) and has grids defined which determine which locations local QNH to correct the radar altitude with. An aircraft overhead AY will be corrected with the AY local QNH. Overhead BLA will be corrected by AY or ML (not at work to check which at the moment). As long as everyone is operating on Area QNH and no local QNH is more than 5 different to Area all is kosher.
AT THE PRESENT TIME, there are no QNH feeds into TAAATS from areas outside radar coverage, but within ADS-B coverage. Hence, TAAATS cannot apply QNH correction. No doubt at some distant point down the track the plan will be to connect QNH sensors at each ADS-B ground station and at that point in time we will be able to use ADS-B altitude below FL130.