dog leg

[cheezyflier]

i have been meaning to ask this question forever, but i keep forgetting.

how come when i fly ifr, atc is continually adjusting my course with little dog legs? what i mean is, i'll be flying on a heading and they will have me turn left about 40 degrees or so. then after holding that heading for about a mile, they turn me back to the original heading. what the heck??!!?
if they want to bump me out farther from the airport so i can turn into the glideslope (this is my guess) then why not do it all at once insead of making 500 turns?

[Thoe6969]

I could never figure that out either,hope someone can come up with an answer.

[Big_Stick]

i have been meaning to ask this question forever, but i keep forgetting.

how come when i fly ifr, atc is continually adjusting my course with little dog legs? what i mean is, i'll be flying on a heading and they will have me turn left about 40 degrees or so. then after holding that heading for about a mile, they turn me back to the original heading. what the heck??!!?
if they want to bump me out farther from the airport so i can turn into the glideslope (this is my guess) then why not do it all at once insead of making 500 turns?

To avoid other traffic. If all planes just took the same straight shot there would be a lot of collisions. The area near a VOR can get real crowded, for example, so the best way to handle this (even though a straight line is the shortest distance between two VORs) is to do a dogleg around the VOR and then tune in your next one.

[heywooood]

well why cant everyone else just watch where I'm going?!! :ernae:

[war.ace]

How do I fly Ifr? what are dog legs and OT how am I suposed to know which way the wind is while I'm airbrone? I dont get what cross wind is, or down wind, all I know is, when I say on final I'm on final approach. I feel so stupid.

edit:sorry if I sound like I'm being rude to anyone, I don't mean to.

[heywooood]

its all about the landing pattern and the approach

I know just enough to be dangerous myself but basically all landing patterns are like a racetrack to one side of the landing strip or the other - depending on whether you are told to fly a left hand or right hand base to final...

upwind means that you are flying into the wind - or that you have come into the airspace of your intended landing field from the downwind direction headed 'into the wind' or in the same direction as you will eventually land from.

downwind is the opposite - you have entered the destination airfields' airspace from the upwind direction and are flying 'with the wind' and headed towards the 'base leg'

a 'left base' approach means that the controller wants your plane to turn left from base to final and a 'right base' approach means that the controller wants your plane to turn right from base to final...

'base leg' is where you have turned from your course that was parallel to the strip to a course that is at 90 deg. - like a 'T' intersection where the long part of the T is the strip and the top of the T is the 'base leg' - if you are on the base leg and have to turn left on to final - that is a 'left base' approach and naturally if you have to turn right from the base leg to land that is a 'right base' approach.

the 'final leg' or short final is where you have lined up with the runway and given yourself time make sure you are at proper altitude and airspeed and have trimmed the plane for landing - you have everything prepared and are ready for anything 'interesting' to happen - like some kinard flying through the pattern with his radio tuned to the wrong channel - or a sudden, random power drop, or a wind gust that pops your altitude and heading way off, or another slammin' rookie to taxi out onto the active just as you begin to flare....

in other words - final approach is where you are prepared for everything else BUT landing the plane - and only allow yourself to do it when nothing else pops up on the way down.

I could be wrong - but thats what I understand about it

[heywooood]

the best thing to do - if you want to know more about this stuff is to join the AOPA and get the 'Flying' magazine subscription - or better yet 'Flight Training'

you get a regular newsletter from AOPA and you learn everything you need to know.

the best part is the bonus AOPA airport directory - it lists hundreds of airports and give you all the pertinent info about each one - its like a phone book and I have yet to find one listed in the book that isnt in FSX...its pretty cool

no - I do not work for the publication or AOPA

[Daube]

i have been meaning to ask this question forever, but i keep forgetting.

how come when i fly ifr, atc is continually adjusting my course with little dog legs? what i mean is, i'll be flying on a heading and they will have me turn left about 40 degrees or so. then after holding that heading for about a mile, they turn me back to the original heading. what the heck??!!?
if they want to bump me out farther from the airport so i can turn into the glideslope (this is my guess) then why not do it all at once insead of making 500 turns?

The reason is very simple: the ATC doesn't take the wind into consideration when giving you a heading. They want you to follow a certain route, which appears on your GPS, and very often the wind will push you away from this route. When you get too far from it, the ATC will give you instructions to get closer, and when you get back on the route, the ATC will tell you again to follow the normal heading, not thinking that the wind will push you away again.

The solution ? Keep an eye on your GPS, and adjust your heading in order to stay on the line. The ATC won't bother you again :)

[IanP]

The solution ? Keep an eye on your GPS, and adjust your heading in order to stay on the line. The ATC won't bother you again :)

Or get a flight computer/whizz wheel and calculate the wind drift from the heading that ATC gives you... ;)

Something else that causes this, particularly on longer legs, is that FS ATC only gives you "round figure" headings, so if you should be flying 022 magnetic, ATC will tell you to fly 020. 026 magnetic? ATC will give you 030. Particularly when combined with wind, as Daube says, this will very quickly lead you out of ATC's "acceptable drift" away from your planned path. As soon as you leave the acceptable error area, you'll get a turn back towards it, then a turn back to the (usually incorrect) round-ten-degree heading.

Ian P.

[Lewis-A2A]

People tend to forget that MSFS itself has a massive learning resource area and tutorials.

All your questions are answered if you take the virtual flight training availible in FS.

[kjb]

To get the current altimeter setting, wind direction and speed, tune ATIS when you're about 30 miles out.

[Big_Stick]

Or get a flight computer/whizz wheel and calculate the wind drift from the heading that ATC gives you... ;)

Something else that causes this, particularly on longer legs, is that FS ATC only gives you "round figure" headings, so if you should be flying 022 magnetic, ATC will tell you to fly 020. 026 magnetic? ATC will give you 030. Particularly when combined with wind, as Daube says, this will very quickly lead you out of ATC's "acceptable drift" away from your planned path. As soon as you leave the acceptable error area, you'll get a turn back towards it, then a turn back to the (usually incorrect) round-ten-degree heading.

Ian P.

Yes, that's all exactly right as well. Basically, ATC "vectors" you to your destination. They keep track of where you are and put you on a sawtooth track. They can't pay attention to wind or compass errors or other factors; they are only concerned with getting you to the threshold of the runway safely whilst avoiding traffic. Just listen up and do what they tell you. If you don't want to fly IFR, cancel it and fly a visual approach.

[war.ace]

One more thing, I want to land on an airport but they say "negative, airport is ifr." how do I tell them I wanna fly ifr?

[cheezyflier]

The solution ? Keep an eye on your GPS, and adjust your heading in order to stay on the line. The ATC won't bother you again :)

that couldn't be it, because atc pulls me off of the pink line nearly everytime i fly ifr. otherwise i could flip the nav/gps switch, and make it follow the gps, and they would never bother me except to switch frequencies and airspace. however, when i have tried this, they pull me off the pink line, and when i put myself back on it they bug me until i resume the path they want me to be on. the next time i fly, i will post a screenshot of the map showing my course vs the pink line.

[war.ace]

woohoo! I did my first landing on ifr! I wonder why they kept making me turn 20 degrees then back to 350 then 20 degrees again then back to 350 for 10 times?

[Daube]

that couldn't be it, because atc pulls me off of the pink line nearly everytime i fly ifr. otherwise i could flip the nav/gps switch, and make it follow the gps, and they would never bother me except to switch frequencies and airspace. however, when i have tried this, they pull me off the pink line, and when i put myself back on it they bug me until i resume the path they want me to be on. the next time i fly, i will post a screenshot of the map showing my course vs the pink line.
The only moment when ATC will push you away from the pink line is when you are about to land. The ATC will not lead you directly to the destination airport like the pink line, it will lead you to the approach path, with the localizer and the IFR stuff etc.... so that you can land directly instead of flying above the airport :)
At least this is my experience in FSX.

[GypsyBaron]

I could never figure that out either,hope someone can come up with an answer.

If you stray more than 3 miles off course on an IFR flight
ATC will intervene to vector you back to the course line.

Paul

[spotlope]

The only moment when ATC will push you away from the pink line is when you are about to land. The ATC will not lead you directly to the destination airport like the pink line, it will lead you to the approach path, with the localizer and the IFR stuff etc.... so that you can land directly instead of flying above the airport :)
At least this is my experience in FSX.

Of course, "about to land" is highly subjective. It seems that FS ATC only knows one kind of plane - a heavy jet. If you fly an IFR plan in, say, a 172, you'll be given the same vectors to final you'd get in a 747 - with the attendant assumption of speed. It's kinda funny--ATC calling out which runway I'll be landing on and beginning to vector me when I've got like an hour left in my flight. I guess we should feel lucky it vectors at all. :woot:

[srgalahad]

I've analyzed the FS ATC from the pilots' perspective since I started flying FS9. First observation - it sometimes vaguely resembles the real thing. Second observation - it has only a few, limited parameters to use so it does struggle.

The zig-zag issue comes from two situations but first understand what the MS 'controller' is doing... as you get close (relative to a/c performance) you get the initial approach clearance which will take you off the direct 'pink line' that you had in the GPS.
You are now being vectored to some sort of initial 'fix' from where the final vectoring will begin. (at that point the clearest way to see it is to go to the GPS, select PROC, select the approach you have been assigned, and select Vectors, select Activate. This will clear the 'direct route' from the GPS display and set the pink line on the final approach course). At this point ATC does have problems with drift and also sector boundaries and altitudes that are invisible to the pilot so you may get the zigzag or repeated back and forth vectors.

Now, ATC aims you at one of 3 points near the airport to be able to issue the final vectors to the ILS or Visual (sort-of downwind, angled in toward a 5-10 mile "base", or angled in to intercept final - based on your current course relative to the landing-runway heading). In all cases if you are going to do an ILS, the final intercept vector is a 30-40 degree angle to hit a 10-12 mile final at approx 3000 agl (this is close to real world - the goal being to intercept the ILS below the glide path, far enough out to become stabilized on course before you intercept the GP). Once you get that final vector, it's all up to you and Otto until you miss the approach.

It may seem like a low-slow aircraft starts to get vectored early, but from what I've seen the algorithm is pretty good at finding the right point to pull you off the Flight Plan course. One thing it does seem to do is want to get you slightly away from the Flight plan route at whatever magic point it deems vectors should begin, even if you end up paralleling the inbound track you had for some time. ATC doesn't do much of a job of vectoring you away from traffic ( it just keeps nagging you) and is horrid at sequencing properly - it has no clue about relative speeds.

My biggest complaint is that MS ATC often tries to kill you! ... to simplify the ATC part and to supposedly help the pilot with no IFR experience it's first choice of runway is the longest ILS runway even if that has a 25kt crosswind at 90 degrees... I guess MS figured everyone would trust a coupled approach and hold on thru the landing! In all my testing, I've never seen it select a more appropriate runway until the winds are near maximum (for the sim, not the pilot/plane) and it's certainly not sophisticated enough to issue a clearance for an "ILS Rwy 28, circle to land Rwy 34" (for example) even with winds 350@ 25.

OK.. so now you can handle vectors... and know how to let Otto fly the ILS for you. First, try it all without Otto... then... What do you do if ATC dies, or you are in multi-player with no built-in ATC? Or your GPS won't load to show you how to get to final? Or you decide you would rather fly an approach to the proper runway (see above). Hit the books and study how to fly inbound to a navaid, transition to the approach, fly the 'full approach' (outbound, procedure turn, inbound) to intercept the localizer -at the right altitude- and fly it all manually. Oh.. and what if the only approach aid is an NDB?
Ever wonder why a lot of pilots never get an IFR rating, or take 30-50 hours to do so? :faint:
BTW, just as in the real world, the best planes to learn IFR in are the decent singles and light twins - 120-160 kts is a good speed range to get there before boredom sets in, but not too fast or complex to get you all confuzzled by too many systems as you are trying to get the checklist complete while bouncing around in Lvl 4 turbulence. (Oh.. and turn the viz down to a couple of miles so you avoid the desire to "peek out the window":hand:

Rob

[TimA]

I must admit I much prefer to fly -- or try to fly -- a procedure, rather than just being vectored to the ILS. Over Christmas I managed my first really decent DME arc (hand flown of course) and was really chuffed, only to discover later I'd misread the chart and had flown it at 15DME instead of 13! :pop4: :whistle:

[cheezyflier]

thank you, that was informative! :wavey:

[war.ace]

I must admit I much prefer to fly -- or try to fly -- a procedure, rather than just being vectored to the ILS. Over Christmas I managed my first really decent DME arc (hand flown of course) and was really chuffed, only to discover later I'd misread the chart and had flown it at 15DME instead of 13! :pop4: :whistle:
dme?

[fliger747]

In the real world it is very unusual to fly a complete procedure due to traffic. At one time the FAA came up with RNAV-VNAV continouous descent procedures where you once on the approach would just fly the complete procedure. However I never did complete one without interruption. I don't think they even offer them anymore. Now it has gotten so bad in some areas that delaying and traffic vectors start over 100 miles out!

Cheers: t.

[Nick C]

dme?

http://en.wikipedia.org/wiki/Distance_Measuring_Equipment

[war.ace]

oh, I saw dme on beechcraft but I have no clue how to use it and I looked for it the help index but it wasnt there

[ryanbatc]

The reason is very simple: the ATC doesn't take the wind into consideration when giving you a heading. They want you to follow a certain route, which appears on your GPS, and very often the wind will push you away from this route. When you get too far from it, the ATC will give you instructions to get closer, and when you get back on the route, the ATC will tell you again to follow the normal heading, not thinking that the wind will push you away again.

This is exactly correct, in the FS world. What I do is take the initial heading then set to GPS mode and set A/P to NAV mode and follow the line lol. That way they won't bug you with headings because you'll be following the GPS course.

Obviously you need to fly the headings during approach though... Or you can request a GPS approach and they'll clear you to an IAF (initial approach fix) and you can just fly the pink line again ahah.

[srgalahad]

Two simple options:
1. as you approach the destination, set weather to "Clear" and continue VFR with ATC off
2. fly direct to destination, cancel IFR when told of your approach, get overhead, press "Y" and slew down to a perfect landing.:whistle:

The ATC option is fine as far as it goes, but it doesn't offer a lot of variety and is OK in a tubeliner with a nice Otto. Remember though, until not that long ago, pilots hand-flew many of the approaches except at the biggest, fanciest airports. Besides, even if you don't need to do it it sure is good practice in scanning the panel and flying the airplane.

Tom, as you head southeast out of ANC, you overfly a lot of places outside radar coverage and with no FMC or RNAV/VNAV published approaches, but it sure does get fuggy in the winter. C'mon across the border and we'll get you refreshed on flying a full 'hockey stick" :173go1:
Rob

[fliger747]

Rob:

Well... they seem to have us on radar till about abeam Petrolovsk-Kamchatsky..... There is supposedly a gap between Shemya and Saint Paul island... suppolsedly.

Sometimes we start getting radar diversions for Anchorage at about Bethel.....

T.

[cheezyflier]

srgalahad, this is a good example of what you were saying in your earlier post

http://i152.photobucket.com/albums/s180/cheezyridr/mapcap.jpg

[srgalahad]

Yep cheezy...
I have a suspicion that the MSFS ATC routines contain something like a "vectoring airspace" so the system drags you off the airway once you are to be vectored, then decides you still need to be headed straight to the airport for a while but in the cool hands of ATC. In these days of FMS et al the airlines would rather stay on the programmed route as long as possible and let Otto do the flying, hence SIDs & STARS that can be computed and profiled in advance.

I've just learned to not expect much from the internal ATC, shut it off and do my own vectoring.

Rob

[cheezyflier]

here is a more extreme example
http://i152.photobucket.com/albums/s180/cheezyridr/fsxmap.jpg