My last flight I tried to reselect another approach from 200 miles out and the first time it deleted all the previous approach way points as it put in the new one but the second time it did not, leaving a mess of 2 approaches worth of way points in the legs page. As I tried to delete the approach way points I did not want in there I inadvertently deleted some from the approach I wanted to keep. So I then deleted everything (I had no more en route way points left to dest) and then re-instituted the desired approach. After this all my t/d and vnav stuff disappeared and the prog page showed my last way point I flew over as the beginning of my destination runway. So no wonder no vnav because it thought I was flying from that point to where I was and back again, I guess. So my question is 2 fold. How do I properly re-select an approach with the least hassle and if I screw up my vnav how do I re-institute my vnav from present position? I cant delete a way point I just flew over or what the fms thought I did, rw19 at destination in this case (you know the one way point at the top of the prog page, last one flown over). I hope this makes sense.

Edited October 18, 201114 yr by denver69

If it deletes the whole plan, that generally means the departing airport was reset I think.In order not to double up on the approach, you need to line select the new STAR,and then the runway both. If you select the new runway only, even if using the sameSTAR, it will leave the old vectors and stack the new ones on top of it.So you always need to reselect both, even if using the same STAR as the firstrunway chosen.If any of this is wrong, I'm sure others will chime in.

Should I delete the approach in the rte page first. This would be a one liner in this section, like ILSRW16R or something. And then select a new approach from the dep/arr? I am wondering if this is the correct procedure. What I have been doing is just using the dep/arr to select a new approach and sometimes it erases the old one and sometimes it does not.

Hi, Do not erase anyhting in the RTE page. Just go to the DEP/ARR page, select STAR and Runway, activate, and that's all.

Thats what I have been doing but half the time it just adds the second approach to the end of the last one w/o deleting. Makes for some task saturation on base for sure.

That's strange, I never experienced this. What version are you using (HotFix) ?

Ive never experienced that either - when i select the new STAR it updates my legs starting at the new STAR leg. Im not sure why that happens to you, but you can always scroll down in the FMC and choose the waypoint you need for your new STAR and just bring it up to that it becomes your next waypoint.

Hey Marc, I'm glad you asked about this I've experienced this on occasion when selecting new approaches do due weather changes. For clarification, were you selecting a new rwy, approach, STAR, or a combination thereof? Also, these compounding waypoints should be broken up with a "discontinuity" message and not simply strewn together as one long flt plan. Verify that is true and then the solution is exactly as Max said: copy the first waypoint of your new desired STAR or approach to the LSK of the first waypoint of the one you wish to replace. You shouldn't need to delete any data; simply replace The FMC will normally automatically update your route without waypoint manipulation so long as you select both the rwy approach and STAR before you activate the changes. Also, if possible, make any desired changes before you're actually flying the STAR (failing to do so is a great way to screw up the 737's LNAV/VNAV profile.) As far as a cause is concered, I believe it has to do with which STARs are used with which approaches. If you're arriving on a northbound STAR and the wind shifts favoring southbound rwys, there may be some discontinuity between the end of the STAR and start of the approach. Hence, you can go DIRECT to the next waypoint but this may put the aircraft in an awkward position. When this happens in real life, you have ATC to vector you accordingly. But alas, this is a sim. ********please feel free to correct me if anything is incorrect, I love to learn********* Good luck to ya bud,-Nathan Jaeb

Hi. I also know if you try to swap the arrival like STAR you have to watch where you're at. If your current position before the point where the STAR begins FMC should change it easy with minor amendments. If you have past the fix where the STAR begins and try to re-enter STAR again and another RWY transition and/or RW it may screw your whole arrival and build crazy route and force you to come back to point which you have already passed. ATC will not be really happy observing that. So if you passed STAR fix just change RW transition and /or RW if need. Do not force same STAR again. I was jumpseating few months ago and saw how pilots were doing that.Hope it helps as well.