BluSdUp,
The answers to some of your questions are covered by a recent UK AAIB statement:-
In accordance with international protocols, the AAIB is investigating the loss of the aircraft. Since Tuesday morning, we have been working closely with international authorities including the US National Transportation Safety Board, the Bureau d’Enquêtes & d’Analyses (BEA) in France and the Junta de Investigación de Accidentes de Aviación Civil (JIACC) in Argentina.
See link:-
https://www.gov.uk/government/news/a...ircraft-n264db