I'm hoping a real world pilot, or someone with the relevent experience, can offer some advice relating to the correct procedures for changing an approach for an ILS landing in the PMDG 737-800. The scenario was for me flying to Ibiza from Barcelona. I did all the route planning and checked the weather at the destination and after producing a plan with an approach to RWY06 in Simbrief and loading it into the CDU went on my way. All was good until I approached LEIB and was told to us RWY24. I then deleted the relevent STAR associated with RWY06 and inserted a new route with elevations and waypoints that would take me onto the ILS for RWY24. All was checked in the CDU, and although the plane flew LNAV correctly, the altitude was incorrect at the different waypoints.

So, I have three questions first, in a scenario such as this, does the pilot need to input a revised route into the CDU or is it OK to simply handfly the aircraft using VFR. I'm assuming this may be the case in real life by asking ATC to be vectored?

Secondly, what did I do wrong, assuming that it was finger trouble at my end, that resulted in the plane not adhering to the information I had put into the FMC?

Thirdly, I have always wondered if the approach should be inputted into the CDU as part of the flightplan at departure, or whether it should be left blank (apart from the arrival aiprort) until approach instructions have been allocated by ATC at arrival.

Help with this will be very much appreciated. Thanks guys.

I am not a real world pilot but here are some thoughts after reading your post:

54 minutes ago, Rockliffe said:

I then deleted the relevent STAR associated with RWY06 and inserted a new route with elevations and waypoints that would take me onto the ILS for RWY24.

I do suppose you also deleted the approach itself?

55 minutes ago, Rockliffe said:

or is it OK to simply handfly the aircraft using VFR

Turning off the AP and flying by hand or following vectors doesn't make it a VFR flight. You still have to follow IFR procedures.

55 minutes ago, Rockliffe said:

Thirdly, I have always wondered if the approach should be inputted into the CDU as part of the flightplan at departure, or whether it should be left blank (apart from the arrival aiprort) until approach instructions have been allocated by ATC at arrival.

Not really sure if this is realistic but here's a tip: I always add the entire approach in the MCDU before starting the engines because that's convenient but... I also ALWAYS copy the flightplan into the secondardy one BEFORE adding the approach. This way I always have a 'clean' plan at hand (without a complete approach in it) which can be made active with a few clicks. After which you can easily add the new approach. Surely beats having to manually delete the STAR, VIA, approach, whatever which can lead to mistakes easily.

5 hours ago, tup61 said:

I am not a real world pilot but here are some thoughts after reading your post:

I do suppose you also deleted the approach itself?

Turning off the AP and flying by hand or following vectors doesn't make it a VFR flight. You still have to follow IFR procedures.

Not really sure if this is realistic but here's a tip: I always add the entire approach in the MCDU before starting the engines because that's convenient but... I also ALWAYS copy the flightplan into the secondardy one BEFORE adding the approach. This way I always have a 'clean' plan at hand (without a complete approach in it) which can be made active with a few clicks. After which you can easily add the new approach. Surely beats having to manually delete the STAR, VIA, approach, whatever which can lead to mistakes easily.

Hi, thanks for the reply, appreciated. 1) deleted the approach? possible I guess. I will pay a little more attention on my next flight and try to duplicate my actions.  2) Sorry my bad, I didn't mean VFR in the true sense, what I was trying to say is that if all the waypoints are deleted on the original approch to RWY24 and I have to make my way to RWY06, what would be the appropriate procedure to follow to make my way to that newly given RWY?  3) your suggestion here make a lot of sense, thanks.

The last time that happened to me, I went to the departure page, and selected the new approach just like I did on the ground before the flight with the original approach. After hitting the exec button, there was a disconnect from my present location. I used heading mode to dial in an intercept course to the first waypoint in the STAR that made sense for my present position. I then went to the legs page and clicked on the LSK for that waypoint, and then clicked the LSK by the top position to make it the active waypoint. Then I just re-engaged LNAV.