The Trident had a Doppler navigator. It may have been made by Decca but I don't think it used Decca navigation. You got a scroll for your route and fed that in at the beginning of the trip. I flew briefly on the Trident and nobody took any notice of the Doppler, but had it running all the same.
In case you are unfamiliar with this, the Doppler gives you speed over the ground and drift angle. If you combine this with your heading you can move the motors on the display appropriately to keep the map correctly under a stylus that indicates where you must now be on the map. As I recall, the stylus drew a line so you could see your track (so far).
A bloke called Andy Mattock did have a pukka BA Trident simulator down near Gatwick but from what I can remember the Doppler Map had been replaced by something else, but I can't swear to it.
Last edited by twistedenginestarter; 10th Aug 2009 at 08:15.