IFR route building methodology[PDF]
- 1 Introduction
- 2 Route Building
- 3 Vertical Flightpath Management
- 4 Validation of the route (only for European routes)
- 5 Conclusion
- 6 See also
- 7 Reference
- 8 Author
In your daily IFR flight operations, you are planning to fly from one airfield to another one. Since the airspaces are getting more and more crowded, you cannot just takeoff, follow a straight line to your destination.
Instead, we will make our way through the various charts, documents and maps at our disposal in order to find an optimized route from our origin till our destination. AIP, Skyvector and the CFMU validator (only for Europe) will no longer hold any secret at the end of your reading.
Generalities about the route
Why is it interesting to pick this route? It is for several reasons:
- It is going from one side to another of Europe which let us deal with a lot of restrictions
- Both airports have SIDs and STARs
- The flight is arriving in Hungary which has a “Free Route Airspace”
Finally, the flight is only 1 hour 40 minutes in average so it is not too long if you want to perform it, at the end of this tutorial.
Step 1 – Get the general direction
First of all, we will plot the great circle path between Paris CDG and Budapest.
- Determine the main direction and location of our flightpath for our flight
- Get the distance between our two airports
- Select our departure exit point, our airways and our arrival entry point.
Open SkyVector.com Click on flightplan. File the departure LFPG, and the destination LHBP. Then press enter. You can also file other fields if you want. For example we can fill the speed field to get the estimated flight time duration. At this point, it should be looking like that (if the background is not the same, just hit the “World Hi” button. It will display the world upper enroute chart.):
So, if we were to follow an orthodromy (the shortest route between two points on Earth), we would fly initially a track of 093°, and the flight would take us 676nm through Europe. The flight would last 1 hour 31 minutes at a ground speed of 450 knots. The forecast flightpath is shown in purple.
In the picture, do you see all that black and blue lines? They represent airways.
Step 2 – Determine our departure waypoint
Get to your chart directory and look for Standard Instrument Departures (SID).
We will use the national France AIP in order to find the adequate departure.
We open the corresponding chart: AD 2 LFPG SID RWY08L-09R -RNAV RANUX LANVI BUBLI DIKOL BAXIR
Step 3 – Determine our arrival waypoint
Get to your chart directory and look now for Standard Terminal Arrival Routes (STAR).
We will use the national Hungary AIP. You can see that Hungary has opted to regroup all STARs per runway.
We can therefore open the corresponding chart: LH_AD_2_LHBP_ARR_31R
Step 4 – Enroute plotting
We are now going to connect these two waypoints (LANVI and VEBOS) in order to create the route.
For example, for the first waypoint after LANVI, I drag the flightpath (clicking left mouse button) onto the EPL VOR. SkyVector will ask which waypoint to attach:
Select EPINAL VOR (113.00 EPL). Note that your flightplan is updated and displays the airway used (UM164):
Repeat the drag-and-select method until you have reached the border of the Hungary FIR:
You should now see this plotting:
We obtain the following flightplan till the Hungarian border:
Vertical Flightpath Management
You must select a correct flight level in order to fly your route.
- Flying Westbound (180°-359°) gives an even flight level.- Flying Eastbound (000°-179°) gives an odd flight level.
Regulatory flight levels
These airways have their own rules: Each route is described in the AIP of the country, AIP Part 2 – ENR Part 3.
Validation of the route (only for European routes)
Please visit the official NOP Network Operations Portal > Tactical tab > Flight Planning section > Structured Editors to perform validation requests: https://www.public.nm.eurocontrol.int/PUBPORTAL/gateway/spec/
Two choices are available: “Free Editor” and “Structured Editor”.
I recommend you to use the Structured Editor. File the fields as if you were filing your flightplan.
After validating, the system should return all the problems found:
Correction of errors
Let’s take these errors one by one:
We need to find another route or if we want to stay on this route, we will have to descent below FL095, which is not acceptable for us.
Go back to SkyVector. Center your map on TRA.
We can see that in fact Skyvector assigned automatically airway Z601. But the relevant airway we were targeting here is: UN491. We should then change to airway T103 at the ZURICH VOR (ZUE)
So the route is changed from: EPL UN491 TRA Z601 BODAN to EPL UN491 ZUE T103 BEMKI
It is another bad selection of airway. We were targeting UT23 all the way long. BEMKI T23 GRZ shall become BEMKI UT23 GRZ
We are now going from ZUE to NUNRI via T103, so we can discard this error.
We use airway T103 on this section: NUNRI T103 BEMKI
Since the restriction is not precise enough, a search in the German AIP for [ED2709A] gives us: “Only available for traffic arriving EDDM/MA/MO ETSA/SI/SL from NUNRI to DISUN”
Therefore, we need to fly along T103 before NUNRI.
Actually, we are now flying on airway T103 from ZUE, so this error is therefore solved.
A common error is not found on this route and is about parity change for flight levels. If you happen to face such restriction, do not forget to add: WPT/NxxxxFxxx where N is the expected speed and F is the new flight level. Climb or descent should be initiated on or after passing the waypoint and not before, and is always subject to ATC clearance.
Now, we will submit the new route through the system and check if there are new errors.
In the other case, it goes for another round of corrections. In our case, we still meet one error:
In that case, we need to reroute. Let’s go back to SkyVector. It’s now about finding a route not too far from the first one to avoid the conflicting area. What happens if we continue from ZUE to DEGES on UN491? We can then fly along UN871 till GAPTO, which is a waypoint of UT23 which is our initial route.
The new section of the route is UN491 DEGES UN871 GAPTO UT23.
Building an IFR route is not something particularly difficult if we take the time to do it correctly. With habit, it will become easier and easier to elaborate an initial route.
- Optimizing your route (our final route is 704NM, giving an increase of 4% in distance compared to
the shortest route possible).
- Elaborate your route taking into account bad weather conditions
- Flying other airspace regulations and restrictions (North Atlantic Tracks, etc…)
- VID 200696 - Creation
- VID 150259 - Update
- VID 531824 - Wiki Integration
DATE OF SUBMISSION
- 00:55, 14 May 2021
- This documentation is copyrighted as part of the intellectual property of the International Virtual Aviation Organisation.
- The content of this documentation is intended for aviation simulation only and must not be used for real aviation operations.