Hi,
Given these facts we possibly could agree on the following
1) assister is a word for which the extent of its meanings has some leeway
2) this leeway apparently seems to change in time
3) most likeky the BEA-writer was not conscious about all this semantic issues this when he used the expression
4) and anyhow we do not know his own perceiption of our subject of discussion.
Bien Amicalement
My last answer about this
syntax thingh
The verb "assister" can indeed be understand .. have the meaning of help someone or the meaning of rescue someone .. etc ...
But as used in the stance of the BEA .. the meaning is the same than "assister a un tournois de tennis"
You can't help a "thing"
Briefing is a "thing"
Vous assistez a une chose .. a un spectacle .. a un évènement
Vous ne pouvez pas aider une chose .. un spectacle .. un évènement
Mais vous pouvez aider .. assister .. secourir une personne .. un animal
C'est juste une question de syntaxe .. le contexte dans lequel le verbe est employé
It's no in the BEA stance two ways meaning ... it's only one .. and it's "attend"
The BEA don't use the verb "assist"
3) most likeky the BEA-writer was not conscious about all this semantic issues this when he used the expression
Indeed and let me wonder if the mother language of BEA french note writer is the french language ....
as it's a gross syntax mistake (if his meaning was to write that the captain was there to give assistance to the two pilots at the briefing)