Trident Flightdeck.

[5025]

Can anyone tell me about the moving chart in the centre of the instrument panel. I believe it was called a Doppler Map, but what was it's function, when was it used etc?

[forget]

It was a mechanically driven paper roller map with position derived from the (marine) Decca Navigator Chain. I seem to remember it was called Dectrac or something like that.

[LowNSlow]

Compare that to the nav display in a 737-800.

How far we've come in such a short time.

[Hew Jampton]

It also used a Doppler system to show drift, track, G/S etc. Four radio beams aimed diagonally down.

[5025]

Thanks for the replies, folks.

Regards,
5025

[Final 3 Greens]

LnS

You're right, but what vision to think of the concept of a moving map long before modern technlogy was available.

The Trident design team must have had some good guys in it.

[twistedenginestarter]

You're right, but what vision to think of the concept of a moving map long before modern technlogy was available

Before the Trident's doppler (which I think was from Decca actually) we already had similar moving map navigators using the Decca system.

The problem with both of these is everybody had to use VOR so there was no point. Doppler also is no good across water and this was about the time accurate INS was arriving on the scene to wipe the floor with all the opposition.

[Spot 4]

First generation TANS (Tactical air navigation system) used Decca and Dopplar for its information. The presentation was a lot more pleasing to the eye then reading 3 clocks and cross refering to a chart from hell, but the accuracy therin remained the same until the advent of GPS. (Which the RNS252 a TANS descendent now employs)

Using the TANS in Central America where Decca was not available was a bummer, but it did sharpen up your time and distance calcs, as skill somewhat lost these days.