Hi, I'm flying the Flight1 C172 and sometimes when I engage autopilot for an ILS approach I notice that I wind up parallel to the runway and I have to manually correct the problem. Is this happening because of wind? In general does autopilot compensate for wind drift? Thank you.

Just because its an ILS does not mean it is straight down the centerline of the runway. You might check your plates for that approach and validate.Regards,Jim

In NAV mode all the autopilot does is try to keep the aircraft in the center of the "beam" of whatever's tuned in (VOR/LOC/GPS waypoint). As a result, it will implictly correct for wind (i.e. it doesn't know about the wind but it knows that it's being blown off the track it's trying to stay on, so it makes the appropriate corrections).As Jim said, perhaps the particular airport you're shooting the approach to has a displaced navaid, although right now I can't remember seeing any ILS approach that doesn't send you right down the center stripe of the runway. It might be an error in the coordinates of the navaid entry in the FS database? Heck I don't know.Dave Blevins

oops..sorry about that. I meant "localizer" approach. LDAHowever, there really are a few ILS approaches that are offset, but they are rare. I believe Macdill AFB has one down in Tampa and a few others in different parts of the world.Best,Jim

Well I just tried a little experiment. I disabled all weather and sure enough when I engaged autopilot ,for an ILS approach, moments later I was perfectly lined up with the runway centerline. This was at KLGA and like you guys mentioned about rare offsets, KLGA is not one of them. So my next question is this. During strong crosswinds, or even light ones, should you fly the approach by hand and make manual corrections for wind or should you let the autopilot fly and compensate for the wind and then disable the autopilot fairly close to the runway (say 1 mile away) to make final corrections? Thanks.

Anyone? :)

I'm not sure what approach you are talking about so I'll give you an example:For RWY31 at LGA, the information for the localizer shows:"OFFSET LOCALIZER ANGLE 1.7 DEGREES. " thus you will not track the centerline (but pretty close). Try using AIRNAV.COM to check the NAVAID details. Look at the LDA/DME for KDCA Rwy 19: "LOC OFFSET ANGLE 37 DEG 30 MIN 33 SEC. "I recalll a setting for the aircraft.cfg that will fine-tune the AP to track the LOC closer but I do not recall the entry. May be try a search of "auto-pilot" on this forum.Does this happen at all airports? JFK, ILS4R (4R, I think) is a CATIII (cat 3) approach and the LOC beam is thinner than the others (4.5*).HTH,Jim

>I'm not sure what approach you are talking about so I'll give>you an example:>>For RWY31 at LGA, the information for the localizer shows:>"OFFSET LOCALIZER ANGLE 1.7 DEGREES. " thus you will not track>the centerline (but pretty close). >>Try using AIRNAV.COM to check the NAVAID details. Look at the>LDA/DME for KDCA Rwy 19: "LOC OFFSET ANGLE 37 DEG 30 MIN 33>SEC. ">>I recalll a setting for the aircraft.cfg that will fine-tune>the AP to track the LOC closer but I do not recall the entry. >May be try a search of "auto-pilot" on this forum.>>Does this happen at all airports? JFK, ILS4R (4R, I think) is>a CATIII (cat 3) approach and the LOC beam is thinner than the>others (4.5*).>>HTH,>>Jim>I understand everything regarding ILS offsets but my question is regarding ILS approaches using autopilot during a significant crosswind as I mentioned in the post above. I don't want to change the settings of the AP. I just want to know what is the proper general procedure during such an approach. Thank you