Who gives Pilots their Departure/Approaches?

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Elon

Filing Flight Plan
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Dec 5, 2016
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Elan
For example, if you're leaving KATL, there are quite a few departures you can select from your flight management system nav database. Does someone tell the pilots which departure to use? If so, who? I guess I have that question because sometimes when listening to ATC, the ATC gives the commands...so is the ATC giving commands identical to the FMS flight plan? What happens if they give different commands? That might be weird if ATC telling you one thing but lateral commands showing another. How often does this occur?

I'm not a pilot but I work in avionics and trying to understand the order of operations when programming/following an FMS-based flight plan.

Thanks!
 
Clearance Delivery or Ground Control give IFR clearances on the ground. While in the air it will be departure or center handing it out.

Practically speaking, if you're picking up an IFR clearance in the air you aren't likely to get a SID. More likely vectors or direct to some fix on your route.

Part of the answer to your question is that when the FMS and ATC disagree, the FMS is always wrong. The cockpit crew will revise the FMS to meet the new instructions from ATC. Seeing that might be beneficial for your design, since inserting/removing/reordering waypoints can be cumbersome in some implementations (hello Apollo 480).

I suggest you find a local IFR pilot and go take a ride to see how it all works. Educational and fun way to spend a morning.
 
The airline dispatcher takes care of the flight planning. The crew doesn't file their own flight plans.
 
Ryanb said:
The airline dispatcher takes care of the flight planning. The crew doesn't file their own flight plans.
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Ryan - in the airline dispatch model, how likely is it the crew will get "cleared as filed"? (heck, any of you pro's can answer too)
 
Where does the dispatcher work, locally? They work for the airline? Or for ATC?
 
If you don't have a dispatcher you make your best guess when filing. But I believe an ATC computer assigns the departure, depending on where you are going and the capability of your aircraft. the controller can sometimes change it if you request something else after you have gotten your clearance.
 
rolivi said:
Ryan - in the airline dispatch model, how likely is it the crew will get "cleared as filed"? (heck, any of you pro's can answer too)
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It doesn't take a professional to know who files airline flight plans. How did I know someone wouldn't be happy with my reply? :rolleyes:
 
Everskyward said:
If you don't have a dispatcher you make your best guess when filing. But I believe an ATC computer assigns the departure, depending on where you are going and the capability of your aircraft. the controller can sometimes change it if you request something else after you have gotten your clearance.
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How does the pilot get the information from the ATC computer?
 
I was based out of KATL for 24 years. Our dispatchers filed out flight plans. Probably cleared as filed 98% of the time, CD would issue our clearance and occasionally the departure would be changed, especially if storms were in the area. Arrivals were pretty much what was filed by dispatch. We also received our clearance via ACARS. Center/approach would change he arrival fairy often based mainly on aircraft workload. Meaning sometimes your filed arrival would be for 26R for example (north side of ATL) and because of traffic and/or weather we'd get another arrival for the south runways, 28 or 27L.
 
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@Ryanb - Not unhappy with your reply. I was asking a real question.

When I file a GA IFR flight plan I don't expect to hear "Cleared as Filed" so I was asking if the big guys hear that more frequently than little guys like me.
 
Elon said:
How does the pilot get the information from the ATC computer?
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From the clearance delivery frequency over the radio.

It would be a good idea to fly along with an instrument pilot on an IFR flight to see how it works. Even in a light aircraft. There are some differences in flight crew roles, but ATC does the same stuff.
 
rolivi said:
@Ryanb - Not unhappy with your reply. I was asking a real question.

When I file a GA IFR flight plan I don't expect to hear "Cleared as Filed" so I was asking if the big guys hear that more frequently than little guys like me.
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Even if you get what you file, the controller is supposed to read the departure part of the clearance, then "as filed".
 
rolivi said:
@Ryanb - Not unhappy with your reply. I was asking a real question.

When I file a GA IFR flight plan I don't expect to hear "Cleared as Filed" so I was asking if the big guys hear that more frequently than little guys like me.
Click to expand...

Depends where you live. Here in the middle of the country I get 'Cleared as filed' no matter what I file (usually direct but I can come up with anything and have yet to get anything but cleared as filed). That does not mean I will not get 'I have an amendment to your route, advise ready to copy' later though so I try to file the route that ATC will want me on. Personal experience or fltplan.com help a lot for that.
 
mscard88 said:
Meaning sometimes your filed arrival would be for 26R for example (north side of ATL) and because of traffic and/or weather we'd get another arrival for the south runways, 28 or 27L.
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How far out would you be when this happened? Enough time to edit your FMS/FMC? Or would you just fly ATC commands from that point to landing?
 
Elon said:
How far out would you be when this happened? Enough time to edit your FMS/FMC? Or would you just fly ATC commands from that point to landing?
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When it usually happened we'd be in ATL approach airspace and they'd clear us to a fix and pick up the new arrival from there. Didn't take much time to reprogram the FMS as we flew often enough that we were very familiar with our FMS. On rare occasions we'd get cleared for a visual approach but as ATL is the busiest airport in the world, that didn't happen very often. Great controllers at ATL.
 
rolivi said:
@Ryanb - Not unhappy with your reply. I was asking a real question.

When I file a GA IFR flight plan I don't expect to hear "Cleared as Filed" so I was asking if the big guys hear that more frequently than little guys like me.
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I'm just a little guy like you buddy. :D
 
Elon said:
Where does the dispatcher work, locally? They work for the airline? Or for ATC?
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The dispatcher works for the pilot, not ATC. They could be employed by the airline or outsourced to a firm that provides dispatching services. They could be physically located anywhere, but they are not associated with ATC. Most private GA flyers do not have a dispatcher and do everything themselves.
 
ACARS comes in on a printer in the cockpit right? Does that inclued ramp control, ground control and tower ACARS as well? Or just approach and center? or what?
 
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Elon said:
For example, if you're leaving KATL, there are quite a few departures you can select from your flight management system nav database. Does someone tell the pilots which departure to use? If so, who? I guess I have that question because sometimes when listening to ATC, the ATC gives the commands...so is the ATC giving commands identical to the FMS flight plan? What happens if they give different commands? That might be weird if ATC telling you one thing but lateral commands showing another. How often does this occur?

I'm not a pilot but I work in avionics and trying to understand the order of operations when programming/following an FMS-based flight plan.

Thanks!
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The clearance will tell us what SID to use. Most of the time, the clearance will be as filed. Sometimes we will have a different route but for the most part, it's the same as our release.
 
Elon said:
How does the pilot get the information from the ATC computer?
Click to expand...
It might help to understand what those departures are. This will be kind of an IFR departure 101 since your questions suggest you don't know much about this.

With some exceptions that aren't important at this point, aircraft operating under Instrument Flight Rules receive instructions from Air Traffic Control telling them what to do that begin when they take off and end when they land. It's called a "clearance" that includes the routes and altitudes for the flight.

The "Departures" you a looking at are just a written and graphic set of the instructions for the beginning of the flight. They are just there to make life easy for both controllers and pilots so the information doesn't have to be given and taken verbally. Just like any other instructions during an IFR flight, they are given by ATC.

Flight Management Systems and RNAV/GPS equipment will allow pilot to input the information. Some systems primarily use by airlines, can have them transferred automatically.

You asked, "What happens if they give different commands? That might be weird if ATC telling you one thing but lateral commands showing another. How often does this occur?"

ATC wins. Things can change. Traffic changes. Winds require a different runway. A common example is that some departures depend on which runway. Loan a departure with runway 13 in the FMS and if told to taxi to runway 35, thye pilot will have to reprogram.​
 
midlifeflyer said:
ATC wins. Things can change. Traffic changes. Winds require a different runway. A common example is that some departures depend on which runway. Loan a departure with runway 13 in the FMS and if told to taxi to runway 35, thye pilot will have to reprogram.
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Let's say your Autopilot/flight-director is tied to your Long Range Navigation Source (FMS, FMC, etc) and ATC changes commands. Will the pilot disconnect the autopilot till they finish updating the LRN flight plan?
 
Elon said:
Let's say your Autopilot/flight-director is tied to your Long Range Navigation Source (FMS, FMC, etc) and ATC changes commands. Will the pilot disconnect the autopilot till they finish updating the LRN flight plan?
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Nope. It will the current course until you've told the FMS to do something else. A lot of FMS's have an "execute" button which basically says, "Are you sure you want to do this." Let's say ATC gives us direct to a fix along the route of flight, we will drive the fix up to the direct to line then execute it when we confirm with the other pilot. The AP stays connected.
 
my mother in law lives with us - so I generally get told what to do anyway so its no big deal . . .
 
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