A "navigateur" (full: Navigateur Officier Système d'Arme / NOSA) is the french word for WSO.
All M2000D fly with a WSO; Rafale Bs do when flown by a crew of 2. Alphajet do occasionnaly.
Tragic event for the French Air Force, 8 of the 10 dead and 6 of the 21 wounded are French, including 3 serious ones.
French victims are crews and engineers.
The other 2 confirmed victims are the Greeks crew of the F-16D.
It crashed on the "french" parking and set fire to 4 aircraft (at least), not that this is much important for now.