Originally Posted by
Kulverstukas
FR24 shows quite reliable horizontal position of route and last known point in this case.
Originally Posted by
peekay4
It would be extremely strange for ADS-B data to be shifted precisely in the runway direction, precisely along the extended centerline, and precisely ending at the actual crash location.
Absent other data, for now it seems more probable that the FR24 data is correct and the aircraft was not on the CAT II ILS DME 26 glideslope.
Originally Posted by
Icelanta
An ILS is an ILS. It guides you towards the touchdown point on a given runway.
Not 4km. Behind it.
Another crosscheck on the positional accuracy of the ADS-B data can be made by looking at the departure taxi from the cargo ramp in HKG to runway 07L. The turns are in the right place and the plane stays right on the centerline. This was hours earlier and things can change or drift if IRS position or faulty radio nav is somehow put into the mix I suppose. This plane was a former SQ freighter, anybody here know how they were spec'd for initial ADS-B installations?
Looking at the vertical approach profile in the FR24 .kml file it looks to me like possibly the glide slope was captured from above. Or, was it chased with vertical speed and paralleled a dot high with the throttles back to try to get on profile and never captured before minimums?
On some aircraft if you arm the approach while above the glideslope you get a roller coaster pitch over to capture so the 'technique' was to get right on the path with vertical speed and LOC and then arm the G/S when it was centered. As things got stable it was easy to forget to arm the glideslope. Or, so I'm told. Nowadays if things aren't right inside the marker you break it off and sort it out before another try. At least, that's what we are supposed to do.
Was this really a stable approach? Take a look at the groundspeeds in the FR24 and FlightAware data. It appears that the plane was still decelerating significantly all the way down the glideslope. This may have been due to a decreasing tailwind in the descent or maybe late configuration for the approach, either way with light runway winds looks like the power was back to lose speed as they approached the runway.
Originally Posted by
Icelanta
Where there any aircraft landing before the ACT, if so, how much before?
On FR24 the previous landing appears to be Aeroflot 1882, an A321 from SVO at about 0010Z, a little over an hour earlier. They appear to touch down in the landing zone and take the mid-field turnoff to the ramp.