I have a few questions around how flight-planning is typically done in real world scenarios, specifically:

1) Pilot2atc allows the user to choose whether atc assigns SIDs/Stars, or the user can include their own selections as part of their flight plan.  Does this "either/or" occur in the real world as well?  Or is there a requirement that the pilot include their SID/STAR in every flight plan, or conversely, that atc must assign those?  If either/or, what would be typical reasons for a pilot designating their own vs. allowing atc to assign?

If the pilot does/can include their own STAR in their flight plan based on expected winds and runways at the destination airport, what happens if those conditions change while enroute?  Does atc override the filed STAR and approach?

2) Are IFR flights expected or required to always follow world airways (be they low or high airways) as they go from waypoint to waypoint?  Put another way, are airways typically expected/required to be included as part of the flight plan?  Or is any flight plan that goes from waypoint to waypoint acceptable, and if so, is that true for both hi and low airways?

3) I'm aware that anything above 18,000 feet is considered "world-hi" and requires IFR navigation, standard altimeter of 2992, etc.  Does world-hi have speed requirements as well, i.e., a minimum speed?  And if an aircraft is unable to maintain that minimum speed, I suppose they are required to use world-low instead?

Thanks!

1) Rules vary from country to country, but in general, filing a flight plan is a request.  ATC reviews it and either accepts it or changes it.  SIDs, STARs are typically for jets.fast turboprops, but some allow slower piston aircraft.  You would have to look at the charts to determine if your aircraft is equiped/able to fly them.  When you get your clearance, you are expected to fly what you are cleared for.  If conditions change, then ATC might amend the clearance in flight.  Wind/weather/runway changes are the most common cause for a change.  

2) You don't have to follow airways if you get direct clearances.  Use of airways is probably declining as navigation equipment is now able to fly direct over long distances using GPS.  This also varies by where you are.  Airway usage is still quite common in most regions of the world. 

3) As far as I know, there are no speed limits to use the "Hi" airways, but most slow aircraft can't get that high reasonably and use the "low" airways.

 

Dave

 

Exactly what I was looking for, thanks Dave!

3 hours ago, mikeklimek said:

I have a few questions around how flight-planning is typically done in real world scenarios, specifically:

1) Pilot2atc allows the user to choose whether atc assigns SIDs/Stars, or the user can include their own selections as part of their flight plan.  Does this "either/or" occur in the real world as well?  Or is there a requirement that the pilot include their SID/STAR in every flight plan, or conversely, that atc must assign those?  If either/or, what would be typical reasons for a pilot designating their own vs. allowing atc to assign?

If the pilot does/can include their own STAR in their flight plan based on expected winds and runways at the destination airport, what happens if those conditions change while enroute?  Does atc override the filed STAR and approach?

2) Are IFR flights expected or required to always follow world airways (be they low or high airways) as they go from waypoint to waypoint?  Put another way, are airways typically expected/required to be included as part of the flight plan?  Or is any flight plan that goes from waypoint to waypoint acceptable, and if so, is that true for both hi and low airways?

3) I'm aware that anything above 18,000 feet is considered "world-hi" and requires IFR navigation, standard altimeter of 2992, etc.  Does world-hi have speed requirements as well, i.e., a minimum speed?  And if an aircraft is unable to maintain that minimum speed, I suppose they are required to use world-low instead?

Thanks!

Speaking strictly from the FAA and US Procedures:

Question #1:  SIDs and STARs are designed to move aircraft efficiently into and out of busy terminal areas.  They are in the FAA's words "System Enhancement" procedures.  A pilot is not required to file a SID or STAR; however, if they indicate that their aircraft is RNAV 1 approved, they can expect ATC automation to assign an RNAV SID or STAR.  For conventional SID and STARs, the pilot has to file "No SIDS/No STARs" in the Field 18, Remarks. Otherwise, you can expect ATC to assign a SID or STAR to the flight.  In most cases, it is to your benefit to file a SID or STAR.

It's not uncommon to file a runway dependent STAR, receive a "cleared as filed route" IFR clearance, and at the other end after local ATC has turned the airport around because of winds to be assigned a completely different STAR on arrival.  This happens at KDFW.  Most RNAV STARs at DFW are runway dependent, and since the south runways are in use 90% of the time, most operators & pilots file the STAR applicable to the south runway landing direction, i.e., the 18's and 17's.  However, 10% of the time the wind blows to the north, and DFW lands on the 36's and 35's.  The airlines often use 'canned" flight plans that are pre-stored in the FAA's ERAM flight planning system with the south flow STARs already filed.  On arrival into Ft. Worth ARTCC (ZFW), ATC has to re-assign the aircraft the north flow STAR.  It's not unusual to have a runway dependent STAR change in-flight, especially on a long flight.  

Question #2:  While direct-to "free flight" was once a dream goal of the NAS, reality soon set in and no one talks about free flight anymore.  Like SIDs and STARs, airways provide structure to route aircraft from SIDs and into STARs at busy terminals. What you "should" file is based on the ATC preferred routes (PrefRoutes).  These are published between city pairs in the FAA Chart Supplement and available on the FAA's fly.faa.gov website under the Route Management Tool: Route Management Tool (faa.gov).   There are NDFC PrefRoutes and Code Departure Routes (CDRs).  PrefRoutes are routes that are normally established between city pairs.  Even if the city pair is not listed, you can look at a departure from a certain ARTCC into a particular city (i.e., airport) and determine where it would be best to join the PrefRoute.   

CDRs are expanded PrefRoutes that ATC can assign for traffic congestion and weather events.  These allow operators and pilots to preplan for possible alternative routing that ATC can clear the aircraft.  If CDRs are available for the airports I am departing from or flying into, I can request that my CFP include fuel burns for these CDRs that I could be assigned.  That way, I know if I can accept them if ATC assigns them as an alternative route. While this was the "original intent" of CDRs, they have now morphed into quasi-PrefRotues.   In fact, the CDRs often reflect the actual preferred routes that ATC wants you fly. For example, there are several CDR routes into KBJC, a Denver satellite airport, that ATC would like pilots to fly and these are included in the CDR routes into KBJC.  If you are flying in from the east, and going around the north side of KDEN into KBJC, your flight interferes with KDEN SIDs and STARs, and ATC needs to dump you down low, below the Class B airspace to get you in.  They much prefer that you arrive from the south...a longer distance to fly...but they can keep you higher and in the Class B longer that way.  

While you do not have to file airways, you should at least look at the PrefRoutes and CDRs to know what ATC wants you file and fly.  If you don't, ATC will likely re-clear you on to those routes, which may incur more track miles and more flight time than if you just did it the right way the first time. 

Then again, if it's 0-dark-thirty, no one really cares what you do what you file. 🙂 

Question #3:  As a Challenger 300/350 pilot flying M0.80 who routinely gets behind a CJ2 at FL410 or FL400 doing M0.70 and therefore has to slow for the other airplane, I can tell you for certain that there are NO speed restrictions on using high altitude airways. 😉  It is what it is...  It's worse if you're in the low thirties or high twenties and run into a turboprop that has gotten to these altitudes. 

Hope this helps...

Rich Boll

 

Very informative, thanks Rich!  In MSFS I'm about to transition into my first "high airway" capable plane, the Daher TBM 930, with an eye to eventually learning the smaller business jets and then the heavies.  This got me to thinking about these questions and what the rules are in the real world.