Sequencing flight plan?

[flighttimer]

I don't quiet understand the term "sequence the flight plan, and extend runway centerline".
Could somebody please explain this to me, and tell me when it should be done please?
Apologies for the silly question.

Thank you in advance
Ques is on the 320 btw.

[Love_joy]

I don't fly the 320, but do fly an all EFIS, FMS driven aircraft.

On nearly all the routes we fly, the arrival is generally a radar vectored ILS approach. The FMS will generally be programmed for either the full procedure, or 'tidied up' to something approximating the path flown on vectors - though it can't be used for NAV legally in such a case. For example, you might have the arrival hold programmed in, and a 'direct' track onward to the centre fix of the approach.

A more correct way of doing this would be to leave the procedure in place as the active plan, and once receiving vectors for final approach path then extend the final approach path outwards. This will clean up the screen, leaving only a magenta line representing the final approach path.

On my current type, an added benefit to this method is a display of lateral offset of final approach path, really useful for non-precision approaches where we currently are not permitted to use RNAV.

Some other systems call this extended centreline an 'intercept' or a Pseudo VOR, PVOR.

Hope this helps, but sounds like what you were after

[HPbleed]

Simple terms as you're obviously in training (this isn't really a "tech question" either)

Sequence the flight plan means make the next waypoint in the fmgs the next waypoint you are expecting to fly to after leaving radar vectors or heading. For example, during an SID, ACT give you radar vectors and take you further away than the 6ish miles required to automatically sequence the flight plan and you end up 30 miles downroute but the next waypoint in the box is the second on the SID. This results in incorrect timings and fuel predictions. It will clear itself when you hit DIR TO but in the meantime delete the points you have already flown past.

Extending the centre line is the same idea. Once ATC take you off the STAR onto radar vectors, you can extend the centre line by entering a DIR TO the centre fix with the radial out entered as the inbound course. Confused? Practice. You'll get shown it during line training. It gives you a more accurate distance to go figure.

[gusting_45]

More importantly if you do not tidy up the flight plan, your TO waypoint on the approach could be behind you and the waypoints will not subsequently sequence. In the event of a go-around the aircraft will try to navigate to the TO waypoint and not via the missed approach routeing.

Red faces all round unless you revert to traditional means of navigation..

[flighttimer]

Makes a lot more sense now.
I understand.
Thank you guys very much for the explanation,

[vilas]

Sequence the flight plan is the only correct term. Extend the center line is missleading because this procedure has nothing to with RW center line. Every approach path is not along the RW center line. A non precision approach could be at an angle of 30 degrees to RW. The purpose is remove irrelavant way points. So that missed approach can be flown in NAV.

[Airbus_a321]

extend RWY centerline, or extended final course, is a very nice feature, but unfortunately this "tool" is only available only on more upgraded FMS versions