Hello everyone,
I am long-term reader, first time poster to PPRuNe.org.
I have followed this thread since the morning after the incident had happened. After some bits 'n' pieces out of a thread I have contributed to in the german community @ flugzeugforum.de had been quoted here yesterday, I decided to sign up here, in order to share the findings we have elaborated there so far.
1. Crash site coordinates:
On May 11th, hand-written coordinates on a sticky note from the situation room have been spread on the internet.
As some of you have already pinpointed, these coordinates don't fit to what is supposed to be the crash site, if you look them up in Google Earth.
The reason for that may be different geodetic datums, as the SAR troops there may be using military topo maps, that do not necessarily use WGS84 as reference datum. Therefore, an offset of coordinates compared to Google Earth and/or other maps may exist.
By comparison of photographs and videos from the crash location to the ground profile in GE, we came to the same conclusion as PJ2 pointed out some posts ago. The point of impact is supposed to be located at 6°42'46.08"S 106°44'7.38"E in Google Earth.
2. Assumed flight path to point of impact:
Based on the first coordinates published on avherald.com on the afternoon of May 10th (6.7045S 106.7373E), as well as further details that became public the same day (descent from 10k to 6k cleared by ATC; coordinates of loss of radar contact; circle round Mt. Salak in clockwise direction), I worked out what I believe to be the route flown by the crew until impact.
As new crash site coordinates from the situation room were published the day after (May 11th), that theory no longer appeared to be valid. But as we found out in the meantime, with the actual crash site now discovered in GE (because coordinates published from the situation room seem to be of a different datum, see above), that theory became valid again (even more than before...).
Here it is, in a nutshell:
Viewing direction in the image above is roughly 200° (SSW). Marked in yellow, the two summits of Mt. Salak and the ridge connecting them.
The plane enters the image from top left corner (descent 10k -> 6k MSL). Then, it performs a clockwise circle round Mt. Salak.
Towards the end, the path is split in three:
Red continuous: assumed flight path to point of impact, based on crash coordinates published on May 10th (following the ground profile along the right-hand slope and thereby accidentially entering the "canyon" that was formed when the formerly cone-shaped caldera sled down).
Red dashed: What I think was the originally planned flight path round the mountain.
Purple: updated flight path to point of impact as of May 13th (based on further research and comparison of pictures and video to Google Earth. Heading at point of impact ~ 210°).