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gclarkso

Fmc Or Atc?

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Hi,When piloting jets, seems you would have to elect to use either the FMC for flight planning, or have ATC direct you to your destination. Are both ever used together? Seems with the default ATC vectoring you 20 degrees to the left, then back 40 degrees to the right (rather frequently), versus the FMC with a predefined flight path, it would be counter-intuitive to use both at the same time. Opinions?Thanks,Gordon Clarkson

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in the modern airliner both FMC/MCDU and ATC are used together.FS ATC has little in common with the real-world.--

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in the modern airliner both FMC/MCDU and ATC are used together.FS ATC has little in common with the real-world.--
Hmmm...so what I'm hearing is...in the FS world, it's one or the other.Thanks,Gordon Clarkson

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I don't know much about FMC's and when/how to use them, but I'm reasonably sure that in the real world you do what ATC tells you to do.

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Hi,When piloting jets, seems you would have to elect to use either the FMC for flight planning, or have ATC direct you to your destination. Are both ever used together? Seems with the default ATC vectoring you 20 degrees to the left, then back 40 degrees to the right (rather frequently), versus the FMC with a predefined flight path, it would be counter-intuitive to use both at the same time. Opinions?Thanks,Gordon Clarkson
I never used default ATC in FS, but I guess if you enter your flight plan both in your FMC and in FS flightplanner, ATC with stick to your flightplan (which you will be flying using your FMC).Using ATC to direct you all the way from departure to destination (thus without a flightplan) is never done irl, at least not in commercial travel.

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HiI would like to encourage you to think of the FMS as a tool, and the ATC system as a supervisor. You are given tools to get your job done (the FMS) but usually your boss will come and tell you what they need you to do right then and there. Case in point:You have just been clearance to start your takeoff roll, climb to xxx feet, and contact xxx Departure on xxx.xx. Youve already got your flight plan showing on the ND, but traffic seperation is a lot more important than following the white line on your ND. So, ATC vectors you throughout your climb to cruis and seperates you from other traffic the entire route. However, they will generally let you fly your route unless there's a traffic conflict potential for whatever reason. This is the same in FS, especially if you use Radar Contact, which btw is much better than default ATC.So, you are getting close to your destination and here is where the difference between Real World, Radar Contact, and default ATC differs the most:The Real World- would encourage you to fly just as you filed, especially if you filed for a STAR (Standard Terminal Arrival Route) and it will basically take you to the airport minus last minute vectoring for the runway in use. However, a weather diversion or some other circumstance may cause you to leave the STAR earlier than expected.Radar Contact- would allow you to fly as filed and to within a few miles of your destination unless you cant make a certain altitude crossing a fix (like in the RW) and some other situations. They then give final vectors to landing.Default FS- would allow you to fly as filed but then anywhere from 30-70 miles out, they start the excessive frequency changes and wide angle vectoring that is a true pain in the pants. Here is where about the only use the FMS is to use it to select your arrival runway and auto tune your ILS, other NavAides, etc. However, you fly the plane according to what ATC says ALWAYS over what your FMS directs you to fly, both IRL and FS.

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HiI would like to encourage you to think of the FMS as a tool, and the ATC system as a supervisor. You are given tools to get your job done (the FMS) but usually your boss will come and tell you what they need you to do right then and there. Case in point:You have just been clearance to start your takeoff roll, climb to xxx feet, and contact xxx Departure on xxx.xx. Youve already got your flight plan showing on the ND, but traffic seperation is a lot more important than following the white line on your ND. So, ATC vectors you throughout your climb to cruis and seperates you from other traffic the entire route. However, they will generally let you fly your route unless there's a traffic conflict potential for whatever reason. This is the same in FS, especially if you use Radar Contact, which btw is much better than default ATC.So, you are getting close to your destination and here is where the difference between Real World, Radar Contact, and default ATC differs the most:The Real World- would encourage you to fly just as you filed, especially if you filed for a STAR (Standard Terminal Arrival Route) and it will basically take you to the airport minus last minute vectoring for the runway in use. However, a weather diversion or some other circumstance may cause you to leave the STAR earlier than expected.Radar Contact- would allow you to fly as filed and to within a few miles of your destination unless you cant make a certain altitude crossing a fix (like in the RW) and some other situations. They then give final vectors to landing.Default FS- would allow you to fly as filed but then anywhere from 30-70 miles out, they start the excessive frequency changes and wide angle vectoring that is a true pain in the pants. Here is where about the only use the FMS is to use it to select your arrival runway and auto tune your ILS, other NavAides, etc. However, you fly the plane according to what ATC says ALWAYS over what your FMS directs you to fly, both IRL and FS.
Very Insightful Eric...Thanks.Gordon Clarkson

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Yes, as in real-life, ATC takes precedence over the FMC. FS's ATC just happens to be rather... slow in the head since it doesn't recognize STARs or DPs, much less have more than a rudimentary concept of aircraft spacing. The FMC is, as one said, a tool. It tells the aircraft what settings to use for auto-throttle on take-off, cruise, and decent, as well as a handful of other useful things so it should always be programmed for the flight whether or not a full flight plan (anything more that departure and arrival airfields) is inputted. The exact routing is only useful for LNAV modes as you can still fly with autopilot via the ALT HOLD and NAV/HDG modes without the route programmed, but FMCs usually have a fit if it doesn't know the points of departure and arrival. The FMC should have the route you filed with FS's ATC though for the most accurate information. Just bear in mind that FS's ATC likes to start vectoring you around 70-100 nautical miles out for whatever reason regardless.Also as mentioned, the FMC cannot take adverse weather or encroaching traffic into consideration so ATC instructions should be adhered to over that of the FMC. The FMC is quite capable of slamming you into other aircraft, mountains, or the center of a thunder storm cell (the tops can reach a good 50,000 feet or so). Needless to say, all three will quickly wreck your day if not end your virtual-life. :(

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Without knowing what aircraft you are flying and thus the FMC/FMS used, I'll just state a couple of tips.Sometimes ATC will take you past or skip waypoints you have in your FMC legs list. As with coupled AP/GPS know how to do a "direct-to" equivalent. In the Boeing FMCs presented in the PMDG 737/747 models and perhaps others of this variety, you go to the legs page containing the waypoint and click the SK button next to the waypoint you wish to go to. This puts the waypoint name in the scratchpad. Then go to legs page one and click the SK at the top of the list to prepare this new waypoint as next. You then can EXE to activate the change and your displayed and active route will change accordingly.To go from your present position (such as during departure vectoring via MCP control) to the top waypoint click the top waypoint twice and EXE the change.This is an example of how an FMC is used as a tool to comply with ATC instructions.

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I have experienced the kind of "human" ATC vectoring, like skipping waypoints in your flight-plan (which are programmed into your legs in your FMC) while flying for VATSIM online. Some aiports actually have a REQUIREMENT for ATC vectoring once you approach the airport at a certain minimum radius (such as EHAM), and this is indicated in the "real-world" charts for EHAM. Others like Munich Franz Josef Strauss (EDDM) are more FMC and flight-plan driven and less ATC vectored (if I recall correctly from my VATSIM flying). In other words, in certain airports, when you file a SID and a STAR, you are left to fly it on your own without much vectoring (directions) by ATC.But the "computer" ATC in FS9 is quite ridiculous. Try flying into Amsterdam Schipol (EHAM) using the built-in ATC in FS9 and you will probably declare a missed approach if you are not careful, due to the "zig zag" that ATC puts you through. So you may want to just disable the FS9 ATC altogether and practice a proper approach to an airport using a detailed STAR and ILS or RADAR navigation, so you actually learn how such an approach is performed and what such an approach entails. Of course, as already stated, ATC ALWAYS precedance over your flight plan and your FMC. BUT, the pilot is still in charge of the SAFETY of the aircraft and has the RIGHT to refuse or to question ATC instructions if he feels that these instructions may endanger the safety of his plane. This is something I had learned from experienced flight-simmers and pilots.John Agbaba

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Without knowing what aircraft you are flying and thus the FMC/FMS used, I'll just state a couple of tips.Sometimes ATC will take you past or skip waypoints you have in your FMC legs list. As with coupled AP/GPS know how to do a "direct-to" equivalent. In the Boeing FMCs presented in the PMDG 737/747 models and perhaps others of this variety, you go to the legs page containing the waypoint and click the SK button next to the waypoint you wish to go to. This puts the waypoint name in the scratchpad. Then go to legs page one and click the SK at the top of the list to prepare this new waypoint as next. You then can EXE to activate the change and your displayed and active route will change accordingly.To go from your present position (such as during departure vectoring via MCP control) to the top waypoint click the top waypoint twice and EXE the change.This is an example of how an FMC is used as a tool to comply with ATC instructions.
Now this is helpful...Thanks Ron.Gordon Clarkson

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Of course, as already stated, ATC ALWAYS precedance over your flight plan and your FMC. BUT, the pilot is still in charge of the SAFETY of the aircraft and has the RIGHT to refuse or to question ATC instructions if he feels that these instructions may endanger the safety of his plane. This is something I had learned from experienced flight-simmers and pilots.
Ah yes. I've been out of the real-world skies long enough I forgot about that magic word, "Unable". I wish I could use it on FS's ATC. "MidCon 461, Turn right heading 280." "Turn right to 280, MidCon 461." *15 seconds later* "MidCon 461, Turn Left heading 250." "Unable, MidCon 461."

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FMS is like the autopilot, you use it to help youwhen ATC tells you something, you do it unless it is not a safe condition (95% u just do it)

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Hi,When piloting jets, seems you would have to elect to use either the FMC for flight planning, or have ATC direct you to your destination. Are both ever used together? Seems with the default ATC vectoring you 20 degrees to the left, then back 40 degrees to the right (rather frequently), versus the FMC with a predefined flight path, it would be counter-intuitive to use both at the same time. Opinions?Thanks,Gordon Clarkson
Ussually both cas the ATC have better things to do than guid you around to the next AP. and they would get confused when you switched stations

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