Hi Mc,
The problem is that the PMDG won't allow some discontinuities to be removed - or so it seems. Although the FMC is acurately modelled, it is not a replica.
Mc has a problem with removing a route discontinuity which occurs after he selects the Arrival or IAP - is this correct? If so then i guess his initial route in the LEGS page might look something like this:
EHAM
>HSD
>REFSO
>TIMEX
>XAMAN
>LOGAN
>TRIPO
>MANGO
>WESUL
>LAM
EGLL
He wants to fly the 09L into Heathrow. So by pressing DEP/ARR he is presented with his choices. I assume he would go for the LAM3A arrival with the LAM TRANSistion (conveniently as this is the last point on his route). So, he makes the selections and takes a look at his LEGS page which now looks like this:
EHAM
>HSD
>REFSO
>TIMEX
>XAMAN
>LOGAN
>TRIPO
>MANGO
>WESUL
>LAM
-----THEN-----
>LOGAN
>TRIPO
>SABER
>BRASO
>LAM12
>LAM
>LAM275D
>(LAM275D-7)
>INTC
>IAA7.5
>RW09L
You can see the problem with the "new" route - it duplictaes itself. This might not be easy to spot if you have already overflown these waypoints. If he tries to insert LOGAN into the discontinuity then he see a message like this:
DISCO INSRTD ATER LAM
He cannot clear the DISCO using the conventional method. Actually, he cannot insert a waypoint that would occur PRIOR to LAM on the usual flightplan. He has to scroll down to find the "second" LAM then select the wapoint after that - in this case >LAM275D and pull that in to fill the DISCO. The FMC is much happier with this ( as it makes more sense than going back along the route you've just flown).
So, if you get an "unfillable" DISCO you are probably trying to sequence a waypoint which is unsequencable - the solution is to scroll down and find the next logical waypointand in doing so you will find that the error in you route is obvious.
Hope this helps.
P.S.
you mention,
"The flight I do is from Schiphol (EHAM) to Heathrow (EGLL) and when I choose runway 09L, I have in my ACT ROUTES: EGLL, IAA93, DISCONTINIUTY, RW09L, IAA?? (can't remember this one).
And when I try to input RW09L into the DISCONTINUITY it keeps saying DISCONTINUITY INSRTD AFTER IAA93."
It looks as though the route sequence is messed up. Try "deleting" IAA93 first before calling up RW09L. Because you have so few waypoints to deal with it is harder. Also, make sure you are not calling up portions of your Missed Approach Procedure!!