Originally Posted by
lederhosen
The pilot flying expedited descent as instructed using an unspecified autopilot mode. The 2500 callout looks to me like it got his attention that things were getting out of control and triggered him to fly manually in order to try and recover the situation
WYLFIWYF, as I warned.
Kit you point out rightly that there is a discrepancy of 18 seconds in the report and say that this is very bad
It's very bad, not least because it has caused you to misunderstand the situation. According to the data, he disconnected
before the 'twenty five hundred' call, not after (print out the FDR plot and draw a pencil line vertically up from the A/P disconnect event). That is what is 'very bad' about a report which contains an important factual inaccuracy. Accident investigation must be done with excruciating precision where
facts are concerned. (I originally pondered going down the rabbit hole of considering the selected altitude might have been set to a lower value than 3,000, a frequent coping strategy on all types when altitude capture might interfere with glideslope intercept from above, and an open descent towards the lower value would serve as some explanation, if the glideslope were not captured - perhaps because manual flight began and the PF was manoeuvering below the FD cue to achieve a higher RoD while becoming task saturated and missed the glideslope capture - but this is all horrid, dangerous, WYLFIWYF conjecture).
A good strategy to recover from being way above the glide is to fully configure and slow right down (lower ground speed less vertical speed needed). This is not something ATC always seem to understand and is definitely not compatible with the instruction to maintain 170 kts.
That's elementary energy management, which anyone on line should know (but not all do - I've found myself with command upgrade candidates who don't get it). The 170 KIAS instruction is a focus for further investigation. Vectoring high and tight, with a minimum speed restriction... It's not too soon to learn from that aspect alone, and that should be one of the outcomes of a competent interim report, if the world can wake up to the fact that it's 2020.
Zum Glück spreche ich genug Deutsch, um
Zahlendrehern zu verstehen.
Ich habe auch Erfahrung mit der französischen elektrische
Familie.