FR24 has no record of the flight meaning 'too low or very old transponder'. As, apparently it had been flying at 5000ft earlier on the flight, one presumes it's either the latter reason, the transponder was u/s from Nantes or it just wasn't turned on.
Seems strange that anyone would allow a 'commercial' flight under such circumstances so I wonder if it was a mate doing a 'favour'?
Last edited by Pilot DAR; 22nd Jan 2019 at 12:29.
Reason: Removed needless quote