Originally Posted by
Bleve
A question for the A320 drivers: When descending through the Transition Level does the altimeter sub-scale setting automatically change from QNE to QNH or do you have to manually change it?
The altitude data sent by the transponder, which is what we're talking about here, isn't affected by the subscale setting - in other words it's always Pressure Altitude (QNE), so not necessarily what the pilot sees if below the TA.
The reason I ask is that The Aviation Herald is reporting that: 'Radar data suggest the aircraft ... appeared to have leveled off at FL068 for one minute [prior to impact]'. The Grid Mora at the point the aircraft commenced descent is 6100. This suggests to me that the crew had set 7000 as a level off altitude for an emergency descent. 7000 is the Grid Mora at the descent point rounded up to the nearest 1000 and the difference between FL068/7000 could be due to the QNE/QNH difference.
See above. In addition, I haven't seen any data so far that actually supports Avherald's assertion that the aircraft levelled off at any stage during the descent.
Originally Posted by
AirScotia
In default of a timestamp, I should have looked at the latitude reading. Doh.
That data does in fact contain timestamps - those are the 10-digit values labelled "mtime". Those appear to be in the form of Unix timestamps (with a 1-second precision), which would make the final value of 1427189963 equivalent to 09:39:23Z yesterday. They will, of course, only be as accurate as the time set on the PC that recorded the data.