Descent Planning and Descent
This guide will explain the correct procedures to plan and fly a descent from cruise altitude through STAR and Instrument Approach up to the final approach.
The actual final approach (ILS approach) will be covered by a separate chapter.
Disclaimer
The level of detail in this guide is meant to get an Airbus A380 beginner safely from cruise level down to the ILS glideslope.
A beginner is defined as someone familiar with flying a GA aircraft or different types of airliners. Aviation terminology and know-how is a requirement to fly any airliner even, in Microsoft Flight Simulator.
Prerequisites
Aircraft is in CRUISE
state and phase as per previous chapters
Chapters / Phases
This guide will cover these phases:
Base Knowledge: Route, Star, Approach and ILS
Basics Information
As we have learned in previous chapters, a flight route begins with an origin airport and a SID to safely guide the aircraft away from the airport to the first waypoint on their actual route. Similar to a SID, the arrival to an airport is done via a STAR (Standard Terminal Arrival Route) and an IAP (Instrument Approach, often APPR) to safely bring the aircraft into a position to land on the destination airport safely and with as little ATC communication as possible.
Standard Terminal Arrival Route (STAR)
STAR
A Standard Terminal Arrival Route (STAR) ensures safe and efficient traffic from the last en-route waypoint to the initial approach fix (IAF) of the Instrument Approach (IAP). It separates aircraft, avoids conflicts and helps with noise abatement through specific routing, levels/altitudes, speed restrictions and checkpoints often with holding areas.
One main objective is, to do this with a minimum of communication between the ATC controller and the pilot. As the STAR is part of the flight plan, a pilot can simply continue from the normal route into the STAR if ATC has not given any other instructions. Sometimes ATC might give an explicit clearance for the STAR or change the STAR to manage traffic and landing situation (different runways, etc.).
Often a STAR contains a clearance point which mustn't be passed without explicit clearance by ATC. If clearance is not given, then a holding must be flown as described in the charts.
Please also have a look at our airliner guide's SIDs and STAR section SIDs and STARS
Find a good overview over charts in our airliner guide: Reading a Chart
Instrument Approach (IAP)
Instrument Approach
The Instrument Approach (IAP or APPR) has similar goals as a SID or STAR - safely bring an aircraft into a position to land while ensuring separation between multiple aircraft, avoiding terrain, support with noise abatement, etc.
IAP are often designed for handling maximum traffic in even bad weather conditions. With only little traffic and good weather, it is quite common that ATC instructs the pilot to leave the approach route by giving the pilot heading vectors for a more direct route to the Final Approach Fix (FAF, also called final approach point).
When flying with Online ATC (VATSIM, IVAO, PilotEdge, ...) expect being vectored to the FAF quite often.
Understand important ILS approach chart features here: Approach Chart
Instrument Landing System (ILS)
Instrument Landing System (ILS)
The Instrument Landing System (ILS) is one of several modern forms of helping an aircraft during its final approach to land even in non-optimal weather situations. ILS uses a localizer for lateral guidance and a glideslope for vertical guidance from the Final Approach Fix down to a minimum at which the pilot needs to perform the final landing sequence visually.
Modern airliner like the A380 are even able to use the ILS to land fully automatically as long as the runway's ILS supports it.
Understand important ILS approach chart features here: Approach Chart
Microsoft Flight Simulator and navigation charts
Although Microsoft Flight Simulator allows some flight planning through the user interface, it is highly recommended to use navigational charts when flying airliners. MSFS' flight planning does not provide sufficient information to correctly fly a STAR or an approach.
There are several good sources for charts - free or subscription based. A good free solution is ChartFox, which only requires a free VATSIM account. One of the most known subscription-based sources for charts is Navigraph. Navigraph has been integrated into the FlyByWire A380X flyPad, whereas Chartfox is TBD.
Also, often a simple internet search will do the trick: Search for "<airport icao code> charts": E.g., "EDDM charts"
1. Planning the Descent and Approach
Situation:
- Aircraft is in
CRUISE
state and phase as per previous chapters. - Distance to destination is ~200NM (on a short flight, start as early as possible and maybe even before the flight).
Pilot's responsibility
Pilot's responsibility
It is the sole responsibility of the pilot to conduct proper flight planning, and especially proper descent planning.
It is not at all ATC's task to do descent planning for pilots by giving descent instructions. On the other hand, ATC often actually gives descent instructions, especially on common routes, as they want the aircraft in their responsibility to be at certain altitudes when approaching the destination airport. Nevertheless, pilots must know when approaching their top of descent and if necessary need to proactively request clearance to descend from ATC.
Good descent and approach planning is the foundation for a successful landing. It has to be done early during the flight or even before the flight.
Important Data Points for Descent Planning:
- Cruise Flight Level: The higher we fly, the earlier we need to start descending. Also for short flights, too high a cruising altitude can make it impossible to actually descend to the destination airport in time. Therefore, verify your flight plan if overall distance and flight level make sense.
- Flight Plan Constraints: STARs often have flight level (FL) or altitude constraints which we must adhere to. We must plan our descent, so we can meet these altitude constraints, even when they themselves are still far away from the destination airport.
- Speed: STARs also regularly have speed constraints which we need to take into consideration as slowing down will cost time and is hard to do while descending. If we start our descent too late, we might not be able to slow down in time as required by a constraint.
- Aircraft capability and passenger comfort: Although not a big concern in the A380, general aircraft capabilities and passenger comfort also come into play.
Step-by-step Guide for Descent Planning
- Read the STAR chart and determine if there are altitude and/or speed constraints which we need to consider.
- Consider the STAR and APPR route as optional and do not count on them to be flown and available for descending. ATC might want to vector us to a different runway or at least shortcut our approach. But they won't be able to if we are still too high for the final approach.
- Determine the first constraint you need to meet. This could be a STAR waypoint with an altitude constraint, the Final Approach Fix altitude or even the airport (or runway) elevation itself.
- Calculate the required distance needed to descend to that waypoint with a standard descent angle of 3°. We can use the FlyByWire flyPad in the cockpit or a simple rule of thumb calculation (details below).
- Use the MCDU PROG page's DIST function to read out the current distance to this waypoint. It is also possible to use the MCDU flight plan page, maps or the NDs distance rings to help determine the current distance.
ECAM PROG page and ND distance rings
ECAM PROG page
The ECAM PROG page can be accessed by pressing the ECAM page button on the lower ECAM display and then selecting the PROG page. This page will show the distance to the next waypoint, the estimated time of arrival at the next waypoint, and the estimated time of arrival at the destination.
TODO: update screenshot for A380X
ND distance rings:
The ND distance rings can be used to determine the distance to a waypoint or fix. The distance rings can be set to a specific distance and will show the distance to the waypoint or fix. The distance rings can be set by pressing the ND button on the lower ECAM display and then selecting the distance rings option.
TODO: update screenshot for A380X
FIX INFO Distance Ring
FIX INFO Distance Ring
A great aid for knowing when to descend is the FIX INFO feature.
You can add a ring around a waypoint or fix with a specified distance. As we need 57NM for our descent from FL320 to FL140 at ABTUM we can set the fix distance ring to 57NM.
Now we can easily see our TOD (top of descent) on the ND.
TODO: update screenshot for A380X
The MCDU FIX INFO page can be accessed by selecting the first waypoint on the F-PLN page and pressing LSK 1L "FIX INFO".
See our feature guide FIX INFO for how to use this function.
TODO: update link/page for A380X
How to Calculate the Required Distance for Descent
Calculate the Required Distance for Descent
Example data:
- Flight to EGKK via STAR TEBRA 2G.
- Flight level FL320.
- STAR constraint at waypoint ABTUM "at FL140".
Example chart:
Copyright © 2021 Navigraph / Jeppesen
"Navigraph Charts are intended for flight simulation use only, not for navigational use."
Using the flyPad:
Standard calculation with 3° descent path:
Calculation with a specific distance to calculate the required descent velocity (V/S):
Rule of Thumb
Rule of Thumb
Distance = "Altitude difference"*3/1000+margin**
Altitude difference: 32000-14000=18000
Times 3: 18000*3=54000
Divided by 1000: 54000/1000=54
Plus margin (~10%): 59NM
The margin can be lower for headwind and larger for tailwind. Some pilots also change the margin to compensate for slowing down while descending.
As can be seen on the chart, there will be a further descent to TIMBA at FL70 and after that (not visible on the
chart above), there will be a descent to the final approach which will be at 2000ft at the Final Approach Fix FF26L.
The same methodology/calculation as our initial descent can be applied to these descents as well, but they require less planning as they are usually designed in a way that an aircraft with a 3° descent angle can make these descents with ease.
ATC will quite often instruct certain altitudes within the STAR and APPR which deviate from the STAR and APPR charts. Please expect such instructions at any time.
Advanced Arrival Planning
TODO: consider removing "advanced" as this shouldbe standard
Important Notice
The following is a more advanced process for planning our arrival. It is obviously important when we want to have a
more realistic experience, but in Microsoft Flight Simulator you can skip this part for now.
This process is best done with an Online ATC service, as the built-in MSFS ATC does not provide the necessary
information at the right time.
For a more advanced arrival planning, we can collect the following information and execute the following steps:
Entering DEST DATA on the MFD
Entering DEST DATA on the MFD
Before we descend, we should also reconfirm our destination runway and input or update our destination data into the MCDU PERF APPR page. This is typically done about 50NM before the starting the descent. We can obtain this data from the destination airport's ATIS information and the airport charts.
TODO: update screenshot for A380X
From ATIS we get: QNH
, TEMP
, MAG WIND
and TRANS LVL
- if not refer to the approach chart.
ATIS Example:
TODO: update with new route to EDDF
GATWICK INFORMATION K TIME 2020, RUNWAY IN USE 26L
TRANSITION LEVEL FL70, SURFACE WIND 260,7 KNOTS
CAVOK TEMPERATURE +16, DEW POINT +12, QNH 1018,
ACKNOWLEDGE RECEIPT OF INFORMATION K AND ADVISE AIRCRAFT
TYPE ON FIRST CONTACT
From the chart, we get Trans level
and BARO
(=DA or MDA) or RADIO
(=RA or DH).
- CAT I ILS uses DA or MDA and is entered into the
BARO
field. - CAT II/III ILS use RA or DH, which is put in the
RADIO
field. BARO
is based on barometric altitude whereasRADIO
is based on radio altitude (distance to ground).
For more information on the different types of minimums, see the Minimums and MDA/DH section on the Approaches page in the airliner flying guide.
Trans level: By ATC
Trans level: By ATC
In the particular example below, the Trans level
field states By ATC
. If you are not flying on a network such as
VATSIM or IVAO, you can try the following things:
- Search online for the real life D-ATIS at your arrival airport (much like the ATIS example above).
- Use the
Trans ALT
+ 1000 ft. - If you have imported your flight plan via our simBrief integration, this value would be autopopulated for you.
ILS in the A380
ILS in the A380
The A380 is capable of a CAT IIIB ILS approach and has an approach category of "C" - see the red area on the chart. (see Wikipedia Aircraft approach category)
In this chart for EGKK 26L ILS there is no DH for CAT IIIB defined - so we can enter "NO" or "NO DH" into the
RADIO
field.
TODO: update text for EDDF
If we are using Microsoft Flight Simulator without any Online ATC services (VATSIM, IVAO, PilotEdge, ...), and using the MSFS built-in ATC, you usually can't request ATIS information for the destination airport at this point. MSFS ATC makes ATIS only available once close to the destination airport.
If we are flying with Online ATC, you can request ATIS via the MCDU-ATSU-AOC
page or your Online ATC network's
client at this time.
TODO: double check this with new MFD
METAR Information
METAR Information
We can in any case request the METAR weather information for the destination airport via the same page.
TODO: update screenshot with new MFD
If we used Simbrief for flight planning, we can also see METAR information on the flyPad after importing the SimBrief plan to the flyPad.
Once we have confirmed the destination runway and the destination data, we are set for the approach, and we can continue to focus on the descent.
TODO: double check this with new MFD
WEATHER AND LANDING INFORMATION ................................... OBTAIN
LANDING ELEVATION .................................................. CHECK
BAROMETRIC REFERENCE .............................................. PRESET
LANDING PERFORMANCE ................................................ CHECK
TODO: VERIFY LANDING CALC WILL BE PRESENT IN NEW FMS
Flight Management System (FMS) Checks
If not already inserted, insert the applicable APPR, STAR, TRANS and APPR VIA in the active flight plan arrival page of the flight management system.
FMS ACTIVE/F-PLN/ARRIVAL PAGE ............................... INSERT/CHECK
DES PANEL OF THE FMS ACTIVE/PERF PAGE ....................... INSERT/CHECK
APPR PANEL OF THE FMS ACTIVE/PERF PAGE ...................... INSERT/CHECK
GA PANEL OF THE FMS ACTIVE/PERF PAGE ............................... CHECK
FMS POSITIONAL/NAVAIDS PAGE ........................................ CHECK
FMS ........................................................... CROSSCHECK
OANS (Onboard Airport Navigation System) and BTV (Brake to Vacate)
If available, set up the OANS and BTV for the destination airport.
OANS
The Onboard Airport Navigation System (OANS), developed jointly by Thales and Airbus, is a groundbreaking technology designed to enhance pilot navigation during airport operations.
Key features of OANS include:
Overview Map Display: OANS provides pilots with an overview map display of the airport apron and taxiways. This display indicates the precise location of the aircraft on the map, aiding pilots during taxiing and ground movements.
Geo-Referenced Map Integration: The system integrates the plane’s position on a high-resolution, geo-referenced map using a standardized Airport Mapping Database. This ensures accurate and clear navigation guidance for pilots, especially when they find themselves in unfamiliar airports after landing.
Efficiency Benefits: By helping pilots navigate airports more efficiently, OANS aims to: - Reduce taxi time. - Streamline airport handling operations. - Maximize turnaround times
Adaptation to Multiple Platforms: Initially certified for the A380, OANS has been adapted to other Airbus platforms, including the A320, A330, A340, and A350 XWB. Thales’s expertise allows effective adaptation of systems designed for newer platforms into earlier ones3.
In summary, OANS bridges the technological gap between the air and the ground, providing pilots with clear and concise directions from landing through arrival at the gate, and vice versa3.
BTV
Brake to Vacate (BTV) is a system that helps pilots to select the most appropriate runway exit for their aircraft based on the aircraft’s current position, speed, and weight. The system calculates the optimal exit based on the aircraft’s deceleration capabilities and the distance to the exit.
By selecting the most appropriate exit, pilots can reduce taxi times and improve airport efficiency. This is especially important for busy airports with high traffic volumes, where every minute saved can help to reduce congestion and improve overall airport operations.
BTV is a valuable tool for pilots, providing them with the information they need to make informed decisions about runway exits. By selecting the most appropriate exit, pilots can help to reduce taxi times, improve airport efficiency, and enhance the overall passenger experience.
RUNWAY SHIFT ................................................. AS REQUIRED
ND MODE ............................................................. PLAN
ND RANGE ............................................................ ZOOM
RUNWAY ............................................................ SELECT
RUNWAY EXIT ....................................................... SELECT
Exit Selection
It is recommended to select the exit in accordance with the runway conditions. It is recommended to select an exit after the wet line to anticipate any changes of runway condition, as well as a smoother deceleration for passenger comfort. It is also recommended to take into account arrival gate, the ground circulation, the runway exit configuration, and the predicted turn around time, which is displayed on the navigation display
AUTO BRAKE/BTV ....................................... SELECT, AS REQUIRED
Brake / BTV
It is recommended to use of the autobrake system to have equal brake pressure and prevent brake overheat. Select the appropriate autobrake mode, depending on the weight, the runway length, the conditions and the winds. However, if the pilot selects the BTV system, set the BTV mode before removing the onboard airport navigation display from the navigation display. It is recommended on contaminated runway to use the autobrake mode 3. It is recommended to use of the HI mode if the BTV mode is not available or on short runway conditions
OANS RUNWAY LENGTH VS CHARTS RUNWAY LENGTH .................... CROSSCHECK
TODO: add link to advanced guide or video
LANDING BRIEFING ................................................. PERFORM
This concludes Descent and Approach Planning.
2. Descent
Situation:
- Aircraft is in
CRUISE
state and phase as per previous chapters. - Descent and approach planning is done.
- First descent point (altitude at certain waypoint) is identified.
- Distance to descent point is calculated, which is called TOD (top of descent).
Descent Clearance from ATC & TOD
A few minutes before we reach our calculated descent point (TOD) we request clearance for descent from ATC if not already given a descent instruction before.
Do NOT start the descent without clearance from ATC.
The A380 has a downward pointing arrow at the TOD to support the pilot with the decision of when to descend.
Ultimately, it is still the pilot's responsibility to calculate and validate the TOD.
When clearance is given, we can start our descent to the flight level or altitude ATC has given us.
DESCENT CLEARANCE ................................................. OBTAIN
CLEARED ALTITUDE ON AUTO FLIGHT SYSTEM CONTROL PANEL ................. SET
ANIT-ICE ..................................................... AS REQUIRED
Starting the Descent
DESCENT ......................................................... INITIATE
ALTITUDE ............................................................ PUSH
How to initiate the descent
For descending, we set the new flight level or altitude in the FCU
with the altitude selector
. We can then
either PUSH the selector for Managed Altitude Mode
(constraints are respected, also known as
DES) or PULL the
selector for Selected Altitude Mode
(constraints are ignored, also known as
OP DES).
TODO: update screenshot with new FCU if needed
What is DES mode
Managed Descent (DES) Mode will follow a calculated vertical profile, this may lead to unexpected occurrences of very high and very low V/S. Users not familiar with Airbus Managed Descent should use OP DES instead as it provides a linear descent most users would expect.
See the Vertical Guidance Guide for more information on using managed vertical modes.
When either of these altitude modes are engaged, the relevant mode will appear in the Second Column of the FMA
,
and will be displayed in green.
(See Vertical Mode Annunciations).
TODO: update links
Using V/S not recommended for beginners
It is not recommended to use V/S for climbing or descending in the A380 (at least not for beginners) as the V/S guidance has priority over the speed guidance, and speed needs to be watched very closely when using V/S.
If the selected target V/S is too high (relative to the current thrust condition and speed), the FMGC will steer the aircraft to the target V/S, but the aircraft will also accelerate or decelerate. When the speed reaches its authorized limit, V/S automatically decreases to maintain the minimum or maximum speed limit.
See also Protections.
TODO: update links
VNAV and ATC in the FlyByWire A380X
In case we are cleared to a lower altitude or flight level with altitude constraints above the clearance
is an ideal scenario for the called so VNAV
autopilot mode, which would be activated by using
"Managed Altitude Mode
" (pushing the ALT selector
).
The autopilot will automatically level off at the constraint and continue descending when the constraint is no longer valid. ATC typically will not clear us to our final target altitude directly, but will give us several step descents down to our required altitude.
ATC will often still expect us to respect the STAR's constraints, although they might have given us a lower clearance. We should then only descent to the constraint's altitude. We repeat the process until we have reached our desired final approach altitude.
DESCENT .......................................................... MONITOR
RATE OF DESCENT ....................................... ADJUST AS REQUIRED
SPEEDBRAKES .................................................. AS REQUIRED
Airline SOPs
Some airline's SOPs (standard operating procedures) might have a different order for the following steps.
At 20,000 feet
CABIN CREW ........................................................ ADVICE
TERRAIN RADAR ................................................ AS REQUIRED
WEATHER RADAR ................................................ AS REQUIRED
Weather Radar
The Weather Radar is currently not available in the A380X. It is planned to be implemented in the future if and when the simulator provides the required weather data.
At 10,000 feet
What and Why?
As we reach the 10,000 foot mark in our descent, we have to take a few more steps to prepare the aircraft to land. We make sure the seatbelt sign is on so passengers are secure and not moving around during descent. We also make sure the landing lights are on so we are visible to other aircraft on approach.
The LS
buttons are turned on so we have the landing system active for when we intercept the ILS.
LANDING LIGHTS ........................................................ ON
SEAT BELTS SIGN ....................................................... ON
CSTR BUTTON ........................................................... ON
LS BUTTON .................................................... AS REQUIRED
NAVAIDS ................................................ AS REQUIRED/CHECK
How and Where?
TODO: add screenshots and description
APPROACH CHECKLIST .............................................. COMPLETE
Approach Checklist
CABIN CREW ............................................................. ADVISE
LANDING DATA .............................................................. SET
AUTOBRAKE/BTV ..................................................... AS REQUIRED
LANDING BRIEFING ...................................................... CONFIRM
ECAM STS ............................................................... NORMAL
ALTIMETER .................................................... ____ QNH/HPA SET
LAND LIGHT ................................................................. ON
MINIMA .................................................................... SET
SEAT BELTS ................................................................. ON
Cabin Crew in real life
In real life, the cabin crew will be asked to prepare the cabin for landing at some point during the descent. The exact moment and process might differ between airlines, but most seem to do this when the Seatbelt Signs are turned on (typically at the latest at 10,000ft).
The Cabin Crew will notify the pilots either by a "Cabin Ready" button (A380) or by a call to the cockpit once they are ready and strapped in themselves. Typically, we will be in final approach by that time.
TODO: check SOP for updated 380 cabin crew
This concludes Starting the Descent.
3. Flying the STAR and Approach
Situation:
- Aircraft is in
DES
phase. - Descent has started (we are after TOD).
- We have not yet reached the first waypoint of the STAR.
MCDU PERF APPR
page is filled (beginners can skip this - see chapter Advanced arrival planning).
Flying the STAR and Approach is very similar to any other part of the route within the flight plan. Apart from descending and adhering to constraints, the lateral flight path just follows the programmed route.
Let the Autopilot do this for you, and just adjust altitude and speed according to the charts or ATC instructions.
ATC Instructions During STAR and Approach
At some point during the descent and when close enough to the airport, we will be instructed by ATC to contact ATC Approach for the airport we are flying into.
Be prepared for ATC instructions to deviate from the STAR or Approach route to separate from other aircraft or to shortcut the approach when there is little traffic. ATC will then typically give you new heading instructions (heading vectors) and will guide you the rest of the STAR and Approach with additional heading instructions until intercepting the ILS localizer.
Example for shortcuts:
ROKIL STAR/Transition EDDM (Munich) 26R - it is only in times with a lot of traffic that we would have to fly the whole downwind part of this transition.
Copyright © 2021 Navigraph / Jeppesen
"Navigraph Charts are intended for flight simulation use only, not for navigational use."
TODO: update to EDDF
4. Intercepting ILS
Situation:
- Aircraft is in
DES
phase. - Aircraft is set up for flight <10,000ft (
seat belt signs
on,landing lights
on, etc.). - We are either within the IAP (Instrument Approach) and at the correct altitude and speed or at a heading vector, altitude, and speed instructed by ATC.
Reaching the beginning of the ILS Approach
At the start of the Instrument Approach (or by ATC vectoring) we will be on a path to the Final Approach Fix and/or intercepting the ILS localizer and eventually the ILS glideslope.
To intercept the ILS, we need to be at the correct altitude and should not have an approach angle larger than 30°.
The LS
button should also be ON
on both the captain and first officer's sides of the FCU.
Copyright © 2021 Navigraph / Jeppesen
"Navigraph Charts are intended for flight simulation use only, not for navigational use."
TODO: update to EDDF
APPROACH PHASE ............................................ CHECK/ACTIVATE
Approach Phase
The aircraft will activate the APPR phase automatically if flown over the pseudo waypoint in NAV mode. However, if the aircraft is in heading or track mode, It is recommended to activate the APPR phase 15 nautical miles from touchdown.
MANAGED SPEED ...................................................... CHECK
Managed Speed
It is recommended to regularly verify the managed speed and to monitor the target speed.
When in NAV, LOC*, or LOC mode is engaged, the aircraft will automatically decelerate at the DECEL waypoint.
SPEEDBRAKES .................................................. AS REQUIRED
More details regarding the ILS approach and landing in the next chapter.
This concludes Intercepting ILS.
Continue with Final Approach and Landing