A couple of days ago I was approaching CYVR’s runway 08R in a Boeing 772, and was about to activate APPR mode to follow the ILS. The CRS1 was set to 83 degrees for the ILS.
I disengage VNAV when I reached 3000 ft. My GPS flight plan took me 3 nm south of the ILS ‘cone’ tip. I disengage LNAV shortly before I arrived at the point where I begin my base turn to intercept the LOC. I change source to NAV1 (ILS 08R freq). I wait to finally cross the “base turn point,” and then I manually adjust the HDG for a right turn to 50 degrees to intercept the LOC at 3000 ft. The ILS approach course for 08R was 83 deg. This gives me an intercept angle of 33 degrees (ik proper ‘max’ is 30 deg but close enough)
My plane is now stable at HDG 50 deg, 188 kts IAS, 3000ft. I tap “APPR” and suddenly my plane veers to the right (i dont mean adjusts a little bit to get an intercept of 30 deg–it was a sudden bank of 20,25 deg and never levelled). I have to disengage autopilot as the plane was turning away from the ILS and entering an uncontrolled trajectory. I then manually turn the plane 360 degrees to return to my base leg for a second attempt, this time smooth.
Hope I described it well…what just happened? Why did the plane go AWOL when all looked good the first time around. Stable SPD, HDG, ALT but yet when I engaged approach it turned unexpectedly. Remember I disengaged VNAV and LNAV before changing navigation source from GPS to NAV1 the first time. Then I hit APPR when I thought I was looking like a stable intercept.
Not sure if I had LNAV when activating APPR on the second time around tho.
if u have any questions just say so in replies; I’ll try to add any info necessary
Hey there! I’ll keep this short, I have this issue too, this is ussaly the plane trying to line up exactly to the LOC cone; it is very obnoxious and disrupts gameplay, by that just my opinion, here is the #features reuquest: Smooth Autopilot Transitions
The very reason I don’t use APPR at all, it’s just something that needs to be fixed ASAP, and I don’t wanna mess up my perfect approach that I flew by turning APPR on, I always land with Instruments, and I recommend you do too! 😉
There are many problems for the APPR, even when you use it right, I know how to use APPR, i have been playing IF for a long time, first thing, when you have it intercepted the nose of the plane goes up, and crashes down, second thing, on final, the nose likes to keep doing that, goes up and down, always, and when you set the speed, the VS becomes super Aggressive
There are so many problems with it, that I call it broken, because it is
Well obviously if this is happening, you’re not using it correctly. You may think you’re using it correctly, but you may not. Just like in the real world, every single thing needs to be accurate. This includes altitude, speed, trim, flaps, whatever it may be.
Rather than giving up on it, make adjustments one at a time and practice. Compare it to a game of baseball. If you keep missing the ball, will you give up and blame it on your bat? No, you’ll get back in the box and make adjustments to hit the ball.
Anyways, Ryan, if you could answer my questions, that would be much appreciated as to helping you fix the problems.
It’s worth noting that APPR isn’t always the issue. All airport ILSes are edited manually by a team of Airport Editors called the Navigation Editors. If you’re interested more in this, check out this post. It’s old, but it’s still relevant today.
Nowadays Fixes, VORs and NDBs are brought in by NavBlue and aren’t done by the Nav team but ILSes still are. Sometimes an airport is updated by one of the Airport Editors and the runways are moved, meaning the ILS data is out of date. Normally the runways are only moved a tiny bit so it’s not an issue, but occasionally something may happen to cause the ILS data to be a long way off.
I may regret this, but if ever you or anyone ever engage APPR and you’re sure you did it at a good time (below the glide slope and on the localizer ideally) but it made a big turn that it should not have, shoot me a message and I’ll give the ILS a look :)
I dont really feel like uploading the video, but I have a vivid memory of it: I disengaged VNAV, LNAV, switched Source to NAV1 (with CRS1 being ILS 83 deg). my flaps were 20 deg, I def inputted 08R (the desired runway) as Nav1, SPD was about 188 kts IAS, trim +30%, was about 50 sec from intercepting LOC i think. activated APPR enroute to the intercept point (HDG was about 50 deg). Once activated APPR, plane banked hard right and never levelled. didnt know where I was headed, so I disengaged and performed a manual 360
A 3nm base is incredibly short, you likely didn’t time the turn to 050 correctly late causing you to overshoot the localizer and possibly the glideslope as well if your base turn was too soon. This would be confirmed with the replay as others have said.