Originally Posted by
broadreach
The accident coordinates provided by a radio amateur last night, based on a farmer's eyewitness account, were 09-47-58 South 53-39-35 West. It is extremely remote but there are small towns and quite a lot of land has been cleared.
Using these preliminary coordinates, the crash site would be roughly 20-30 miles east of UZ6, the airway between Manaus and Brasilia. It is also in the Manaus Center airspace, (or Amazonicas if you prefer), and about 60 miles north of the changeover for Brasilia Center.
From routinely operating in that airspace, radio communications on the southern end of the Manaus airspace can be problematic. Relays and frequency hopping are the norm. If these coordinates are accurate, the southbound aircraft would be told by Manaus to contact Brasilia at the boundry point. It's possible that the aircraft wouldn't be able to hear Manaus or Brasilia in this area. My memory is a little vague on the radar contact issue in this area, but I think it is less than optimal or non-existent. Over the last 10 years, radar coverage has improved dramatically in Brasil, but can be spotty in some isolated areas.
One more note on the remote location. From viewing at night, small, isolated shacks with lightbulbs are generally separated by 50-100 miles.