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Guest william273

localizer intercept angle

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ok, so they say about 30 degrees or less to intercept the localizer.not sure about smaller aircraft but with a heavy jet like the A30030 degrees and even 20 almost seem a bit much to do manually. maybe it's meand probably is but what's a good angle to use and a good distance too. not using ATC either pretty much just raw data with no GPS map.i also want to do this smoothly with no erratic ham fisted fighter jock movements. i'm playing around with airspeeds and other thingsand thought about posting here while i'm doing these test flights. no autopilot. william

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in USA under radar approach the FAA defines that the intercept angle for an aircraft must be sufficiently shallow to permit a smooth transition to the final approach course. this means that when less than 2nm from the 'approach gate' (which is ~1nm from the final approach fix) the angles <20deg. if further than 2nm from the 'approach gate' the course is no >30deg.even with the above said, remember - FS ATC don't play by the rules.--

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If you go to LAX and watch the aircraft landing to the west you will see that the guys coming in from the north are turned right by 90 degrees by the approach controller, who is usually building his "string of pearls" with 3-mile separation, both issues being in complete violation of the regs as written.ATC as she is written and ATC as she is practiced are two different things.

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thanks guys. well i'm having a heck of a time trying to get settled on the localizer at the IAF with anything between 20-30 degrees.the autopilot does it pretty well but manually it almost seems impossible. can't remember what the winds were but not enough to cause this much of a problem i wouldn't think.1 mile from the final approach fix? forget that...way to close...no can do. i see them all the time making those tight 20-30 degree turns to final but i assume they're on autopilot. any advice on doing it manually?from the IAF a 10-15 degree intercept might be workable, anything closer and greater than 15 degrees seems impossible. how do theydo it manually? thanks again for your feedback. william

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tried a 15 degree intercept and that is MUCH better. thanks alot guys. william

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William273,As you will learn, the trick to manual sharp turns (indeed to any turn) is to anticipate the aircraft's rate of roll response on the rollin from the old heading and on the rollout to the new heading.

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hi mikeyour right, when i stop and think about it, it's all pretty basic.i've been in a bad habit of depending too much on the autopilot.thanks, william

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You can also stand in central London and watch aircrraft making 90 deg (and sometimes more)turns onto the extended runway centre line when Heathrow (EGLL)is operating westerlies.There's no hard and fast rule in the UK. The Manual of Air Traffic Control Services states that closing headings are typically 40 deg offset from the final approach track but that individual ATC units may uses different offsets.

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>1 mile from the final approach fix? forget that...way to close...no can do.Correct. Normal intercept heading is 30deg. That's what ATC gives you as well.But that's at least onto a 10NM final!On some airports they even put you on a 40NM final.But in case of a 40NM final I fly with LNAV or HDG until 10-15NM because the localiser is not too stable at this distance. RegardsBernt Capt 767

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Bernt,In the immortal words of Galileo, "Still, it moves."I'm pretty sure that the Stadium approach into LAX has that 90-degree turn about 5 miles from the runway threshhold.Combine that with 3 mile separation and you have an aerial dance that is truly breathtaking to behold. Skilled controllers, skilled pilots, everybody knowing what they're doing, and doing it well.

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>I'm pretty sure that the Stadium approach into LAX has that 90-degree turn about 5 miles from the runway threshhold.What do you mean with a 90-degree turn?You mean ATC leads you with a 90deg intercept angle to the ILS?I've seen that, but only a few times and that was in the former german democratic republic. If ATC is really good a turn at 4-5NM is no problem. ATC knows your ground speed and hence your turning radius.So when the controller issues a turn, (still onto a 30deg intercept heading!), the FD and/or autopilot captures the Localizer during the turn and continues with the same bank angle until it is exactly on the centerline. RegardsBernt Capt 767

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Hi Bernt,All I know is that it is one smooth, continous 90 degree turn onto the localizer. I know this because I have a favorite place to stand on a side street among the approach lights and I can watch all the action starting when the inbound aircraft (heading west) turn their landing lights on maybe 20 miles out, and when the southbound aircraft to be turned also are about 20 miles north of the localizer.The turned aircraft in question are coming down from the north, probably from northern California, etc. On this approach they handle nothing larger than 737s, and the traffic is about an equal mixture of 737s, bizjets and turboprops. The heavies go to the almost parallel runway about 3/4 mile south.

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i'm more comfortable with a long final like that, thanks Bernt.

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