Guide to Airliner Simulation - Part 2

An Introduction to Flight Planning

Before pushing back from the gate, we need to have an Instrument Flight Rules (IFR) flight plan. We could use the default FSX/P3D flight planner, however, when it comes to creating a realistic route, it doesn’t really cut the mustard. Fortunately, there are several third-party applications/websites that contain a database of real-world routes, which we can use to make the flying experience both more realistic and interesting.

img_44-1_5.jpg
Understanding the complex route network can be intimidating, but there are several tools at our disposal to make the task more manageable.

Essentially, an IFR flight plan consists of three parts: the route, the Standard Instrument Departure (SID) and a Standard Instrument Arrival (STAR). The latter two are pre-determined procedures for routing arriving and departing aircraft to and from the runway to the route. We need to know the ICAO codes (refer to our guide to ICAO codes in the previous issue) for our departure and arrival airport, as well as an alternate in case we need to divert. Other factors that need to be taken into consideration are: fuel requirements and Estimated Time of Arrival (ETA). We should also establish our cruise altitude and aircraft type, so we know our approximate cruise speed, and finally, for those among us who are more meticulous, the winds aloft.

img_46-2_5.jpg
In the real world, the airspace in Europe is heavily congested as is illustrated from this image from Flightradar24. It is an excellent website for tracking live traffic. Photo Courtesy of Flightradar24.com

The route

We usually travel between airports using airways – think of them as highways in the sky. Airways are joined up by waypoints, which can either be radio beacons (VORs/NDBs) or RNAV fixes. Unlike geographical fixes, RNAV fixes don’t exist in the physical sense but are determined by a bearing and distance from other waypoints. Finally, intersections are points where two airways cross (or intersect) each other. Although airways don’t have links with geographic features, some have an historical significance. For example, over central Asia, some routes follow the old Silk Road – you can even make out the camel trails on clear days.

Airways are also classified by altitude. In Europe (and other parts of the world), they are called as upper level airways above FL195 and are designated with the letter ‘U’. So, for example, N601 becomes UN601. In the US, they are called Jet Airways above FL180, the transition altitude in the States. Below FL180 they are called ‘Victor Airways’.
Finally, our cruise altitude is determined by what direction we are travelling. When flying IFR in a westerly direction (180° to 359° magnetic course), we should file for ‘even’ altitudes Above Mean Sea Level (AMSL) such as FL240, FL260, and FL280 and if you are going east (360° to 179°) you should fly odd altitudes ie FL250, FL270 and FL290, so there is a 1,000ft separation between aircraft. Above FL290 this separation is increased to 2,000ft, so going east, we should file for FL290, FL330 etc, and when travelling west, we should file for FL310, FL350 etc. However, these are more guidelines than rules and we can expect to be assigned different flight levels by ATC depending on what part of the world we are flying.

img_45-3_3.jpg
It is a good idea to get a pictorial overview of our route before setting off.

Odds and evens...

When flying VFR in an easterly direction, we should cruise at odd thousands of feet AMSL altitude +500 (eg 3,500, 5,500 etc); when heading west, we should fly at even thousands of feet AMSL altitude +500 feet (eg 4,500, 6,500 etc).

Transition altitude

During the climb phase, at some point we need to set the altimeters to standard (1013.2Mb/29,92in Hg). This is known as the transitional altitude. It varies considerably between countries and can range from 3,000ft and 18,000ft. For example, in the US it is 18,000ft, whereas in Europe it is usually around 5,000 to 6,000ft, or even as low as 3,000ft in some countries. During the descent, we switch back to the local pressure setting also known as QNH. We refer to this as the transition level which is the lowest flight level above the transition altitude. When flying above the transition altitude we refer to our altitude as flight levels, as an example FL350, but below the transition altitude we use feet, eg 12,000ft.

img_45-1_4.jpg
Once we have cleared the Brookmans Park waypoint, we can climb to our cruise level. We must remember to switch the altimeter to standard (1013Mb/2992in HG) when we pass our transition altitude of 6,000ft.

SIDs (Standard Instrument Departures) and STAR (Standard Instrument Arrivals)

The purpose of a SID is to route departing aircraft on a fixed track from the runway to the first waypoint on the route usually called a transition. SIDs usually consist of complex procedures, with speed and altitude restrictions, which often require RNAV-capable aircraft.

STARs are designed to funnel arriving aircraft so they can be sequenced by ATC for the approach. They are designed to route inbound traffic from the last waypoint on the route to the Initial Approach Fix (IAF). Like SIDs, STARs include a lateral track and a vertical profile that often contain speed and altitude restrictions. Not all airports have published SIDs or STARs but they are commonly found at large hubs or airports with high terrain.

In Europe, each runway is likely to have a dedicated procedure and each SID/STAR is often named after the first/last waypoint on the route, followed by a revision number such as BPK 6J (incidentally this is the SID for Runway 09R at EGLL – London Heathrow). Airports that have a high traffic volume can have several transitions to provide separation for arriving aircraft.

In the US, SIDs serve the same purpose of routing departing aircraft to the first waypoint on the airways or in the case of STARs, to the IAF. However, they are often named after waypoints or geographical features and a single STAR can serve several runways.

img_45-2_4.jpg
Some Standard Instrument Departures (SIDS) have speed and altitude constraints, which are stated on the relevant charts.
img_47-1_3.jpg
When flying the BPK 6J, we must stay below 6,000ft until the BPK waypoint or until cleared higher by ATC. We also have a speed limit of 250kts below 10,000ft.

Fuel

So how much fuel should we take? The ICAO minimum requirements say we need enough fuel to get us to our destination, then our alternate in case we need to divert, plus 45 minutes reserve or holding fuel. Personally, I like to add around 30-60 minutes extra fuel in case of unexpected delays but it depends on the circumstances. A delay during a short hop flight in Europe isn’t a big drama but on longhaul flights, stronger-than-expected headwinds can more easily result in a low fuel situation.

Weather

If using live weather, we also need to check the weather forecast using Terminal Aerodrome Forecasts (TAFs). These are issued along with Meteorological Aviation Reports (METARS) at airports and generally apply to a 24- or 30-hour period. We can pick up forecasts from programs such as Active Sky or there are several websites available. I use AeroWeather, which is a mobile app for real world forecasts or www.aviationweather.gov.

img_46-3_3.jpg
We can pick up the frequency of ground-based navaids from charts. In this case, we have Brookmans Park (BPK) on 117.5MHz.

Putting it all together

Flight plans are written out in a fixed format, so once you understand one, you should be able to make out other routes. For example, going from Heathrow (EGLL) to Schiphol (EHAM), the flight plan might look something like this: BPK5K BPK Q295 CLN L620 REDFA REDFA1A

The first part, BPK5K tells us we will be using the Brookmans Park 5K SID and from the chart we can see it is for Runway 09L. The last waypoint on the SID is BPK or the Brookmans Park VOR and this is where we join the airway system. We take Q295 to CLN (Clacton VOR) on the east coast of the UK. Here, we pick up the L620 airway to the REDFA waypoint. This is also the point where we transition to the REDFA1A STAR. We then take the REDFA1A arrival to the initial approach fix.

ATC would normally vector us on to the IAF, but if we are flying solo, we need to set the aircraft up to intercept the IAF and on to the final approach fix where we pick up the ILS.

img_46-1_5.jpg
We should review our arrival procedure before entering the Standard Instrument Arrival (STAR) so we are familiar with speed and altitude constraints.

AIRAC Cycles and Navigraph

In real aviation, making sure the charts and navigation data is up-to-date is very important. In flight simulation, this is more problematic as the navigation database in the FMC (Flight Management Computer) is probably different from the charts we are looking at and this is also likely to be different to the data in flight simulator. For example, shooting an ILS in low visibility when the frequencies don’t match up can really ruin your day.

This brings us to the AIRAC database. It is an integral part of an FMC that is updated every 28 days and contains information on waypoints/intersections, airways, navigation aids and SIDs/STARs.

Most add-on aircraft come with old AIRAC data but we can use the subscription service from Navigraph to update the database in the FMC to the latest version. You can also subscribe to Navigraph Charts, which contains airport and en route charts by Jeppesen for most airports around the world. It works on Apple and Android devices, so we can view charts on a tablet, giving this an extra immersion factor. We can of course download charts from various sources on the internet, but Navigraph gives us the AIRAC data for the FMC and charts from one source. Personally, I would find it difficult to live without it. You can find out more at www.navigraph.com.

FSX/P3D Navaids update

While Navigraph takes care of AIRAC updates for the FMC and charts, we still have the issue of the navigation data in our simulator being out of date. This is the core scenery data stored in the BGL files and is different from the FMC database. We can however use a website called www.aero.sors.fr to take care of this for us. We can download a small setup program, which will import the latest AIRAC data (BGL files) into FSX and Prepar3D. You can find out more on www.aero.sors.fr/navaids3.html. In X-Plane, the AIRAC data is updated automatically if you have an active subscription with Navigraph.

Tools of the trade

There are several flight planning tools of varying complexity that can be used to plan real-world flight plans. We have the choice of doing a comprehensive plan where we log every minute detail from wind layers down to the tail number of the aircraft or we can go for the quick and dirty approach and just use the basic information – it is purely down to personal taste. The following are the ones I use.

vRoute

vRoute is one of my favourite flight planners. You simply pick your departure and destination airport and you will be given a selection of routes. It is quick and easy to use and comes in both a free and a premium or payware version. The latter offers additional features such as a greater selection of SIDs and STARs, weather reports, fuel calculations and a facility to export flight plans to the FMC (these are called company routes and we will cover those in a later article). It is an excellent flight planner if you are just starting out in the exciting world of airliner simulation. You can find out more on www.vroute.net.

SimBrief

A more detailed example is SimBrief, which consists of tools such as weather reports, aircraft performance data with an option to export company routes etc. We can even build our own fleet, save flight plans and if you have a Navigraph subscription you can unlock the latest nav data. It is more akin to a dispatch system and consequently takes slightly longer to get to grips with. It is free but you need to register. More information is on www.simbrief.com

PFPX

Professional Flight Planner X (PFPX) is a comprehensive flight planning application developed by real-world pilots and dispatchers, which enables you to create professional quality flight plans like those used by real-world airlines.

You need to buy the program and for full access to all the features such as live weather, you need to purchase a yearly subscription (first year is free) but you can extract weather from Active Sky if you own that. Like the previous planners, it also has the option to export company routes to various addon aircraft. (www.flightsimsoft.com/pfpx)

Other useful tools

RouteFinder (http://rfinder.asalink.net/free/). You simply enter a departure and destination along with flight level and it will give you a route instantly.

Sky Vector (www.skyvector.com) consists of worldwide aeronautical charts and online maps that can be used for flight planning. It doesn’t come with built-in flight plans but you can bring up high or low altitude airways or VFR maps and make flight plans from scratch. It is aimed at real aviation rather than flight simulation, but I find it to be an excellent tool, although I use it mostly for VFR flying and creating flight plans from scratch.

img_47-2_3.jpg
Next time we will find out how to enter the flight plan into the Control Display Unit (CDU). In Airbus jets, this is called a Multi-Function Control and Display Unit (MCDU).

Conclusion

To summarise, get familiar with the route, have a look at charts of your departure and destination airports, including where your alternates are. Study your SIDs/STARs before taking off. Preparation is the key to a successful flight. Next time we will go back to the ‘office’ and start working through the cockpit preparation and start becoming familiar with the FMC.

Finally, please note that all of the charts accompanying this tutorial are Copyright © 2017 Jeppesen. All rights reserved. Charts and NavData(TM) are made available to the flight simulation community by Navigraph at www.navigraph.com

By Richard Benedikz