Dassault is still working to pinpoint the cause of "untimely radio-altimeter lock-up[s]"--are there really timely ones?--on Dassault 7Xs, according to a recently issued EASA airworthiness directive
The condition results in a negative distance to ground being reported, even when the aircraft is flying "at medium or high altitude."
Dassaut and EASA issued an initial (and quickly revised
) AD on the problem late last year; the new directive (.pdf)
orders operators to follow new interim procedures developed by Dassault if the problem occurs.