Descent and Approach

Hi everyone!

Lately, I am having lots of issues on my descent and approach. I usually check my time and start ny descent like 20 minutes prior to my destination. However, I would like to make it more accurate and put more realism into it…

I have checked alot of posts on IF and I have tried several ones such as Current Alt- Target Alt etc… and I could not get it still because I have some other questions too apart from descending.

What about the flaps all the way from descending to approach? What about our airspeed? And if ever someone could really help me to have a good descent I do appreciate it alot!!!

Thank u


Without a full blown flight management computer the math is going to vary with all the different methods. The time in your bar is the ETA given your current speed. Most of the calculations take into account your ground speed which will change during your descent. Especially once you get below 10k.

I usually start my descent about 120ish NM. If there is Approach ATC I will go down to 16-17k before contacting them 65nm out who will then direct me in while giving me altitude commands along the way. Some planes you need to descend with spoilers on to avoid gaining speed. Flaps are usually dictated based on your speed so you shouldnt really need them until you are close to final. Again, each plane has different speeds for flaps.

It comes down to practice and trial and error to find what works best for you and that plane.


It’s definitely more down to trial and error than anything… I initially start my descent from cruise at roughly -1500 to -2000 and adjust as I go.

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Adding on to what Chris said (without the computer), traffic control and wind speeds/direction should also be taken into consideration when your planning your descent.

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I always like to have a descent rate of -2000fpm, so do this.

Step 1: Make sure that your flight plan ends at the localizer for the runway you are landing on. It makes the math easier.

Step 2: Determine what altitude you want to be at when you intercept the localizer. I just add 3K feet to the airports elevation and round to the nearest thousand.

Step 3: Subtract that number from your current altitude.

Step 4: Divide that number by two, then convert it. (10,000ft = 10:00).

Step 5: Subtract that number by two just to be safe. Your speed will change as you descend, and it will affect your ETA.

Step 6: When your “ETA to Destination” gauge in the HUD reaches that number, start your descent.

Step 7: Descend in intervals to make sure you don’t descend to early. (30’000, 20’000, 10’000,). You will have to keep making calculations.

Step 8: Level the plane off at around 10’100 feet. Then, when it is time, start slowing down. Repeat steps 2 and 3 to find this.

Step 9: Descend to your desired altitude, then intercept the localizer.

Step 10: Land.


This is good one… though is there any way we can do this through getting our nautical miles?
1- start descent when you reach 70nm from FL30 to FL10
2-then 10K to 3K
3-then when established on the localizer you take it manually and make ur approach and land…

I have actually seen some posts on this and I like it but just seems it is not getting right all the time perhaps airport elevation is something we need to take into consideration?

I will use this as an example. At 36,000 feet I will descend between 120-140 nm depending on if I have a tailwind or headwind. I want to be at between 14,000-16,000 feet when I am 50 nm to my destination.


Hi there. Ther is some great threads already on this forum on this very subject. Rather than re-write all the advise I will point you in the direction of this thread, however there are a few more out there worth using the search button for!

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Very much appreciated
Thank you!

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The easiest way for me is to follow a STAR (standard terminal arrival) which is a path that follows a series of waypoints and sets you up for an approach. Most STARS have altitude and speed requirements for most waypoints, which help you determine when/ how fast to descend. Here’s what a STAR looks like.

As you can see, it gives you altitudes and speeds for most waypoints!


For me, the easiest is the following: Altitude x 3 = Nm to start descend. For example your ALT is 18.000m x 3 = 54.000 (zeros out, 54 Nm). My VS is -1.800 ft

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Being that it’s aircraft dependent on speeds in KIAS and V/S and when trying to get to assigned altitudes and speeds via SIDS/Stars without ATC and en route systems I have a bit of a weird system.

My altitude minus airfield elevation. Say I’m at 37,000 and airfield is at 1000 so I need to descend 36,000

Drop the 0s and I multiply by altitude by 3.9
36x3.9=140.4 and I add 1km per 10 kt tailwind
Which usually is around 18 minutes out if I have my entire approach already in the flight plan per the arrival procedures.

Depending on aircraft set speed to m .77-79 and V/s to -2000

I turn off speed setting at 28,000 so the KIAS keeps climbing at switchover to maintain that mach number till I get to 300-320 KIAS and still keep v/s at -2000

Once I start getting into around 18K I start slowing to 270 KIAS, then to 250.

I’m usually pretty close to the 12-14k point where the arrival plate tells me I need to be at 250 KIAS then my v/s by then is at -1000

From there it’s slowing to 210-180 down to the ILS intercept and turn for final. Depending if I need to go downwind or not.

Yeah it’s flawed but works for me for the game and yeah each flight is different and I do adjust


This is a very nice way but how do you get this? And even if through third party website the waypoints on IF may differ

IF has most of the waypoints, and I’m pretty sure they have all waypoints in the U.S. SkyVector has free charts for every airport in the U.S. at least. If you want charts for airports in Europe or Asia, etc., you would most likely need a paid subscription to a website/app. Although sometimes I just type in for example ‘EDDF Charts’ and I’ll get all of the documents on Safari. Hope that helped.

Yes, big time! Thank you very much!!

I do the following:
Flight altitude - landing altitude * 3 example landing in SBGR (Guarulhos) 2.457ft Flying to FL310 (31,000ft) 31,000-2,500 = 28,500 * 3 = 85,500 “Note can make the division by 1000 more do not think so necessary” That is your TOD and 85.5nm now the key point the speed of decide and M 0.70 and then 250kts so you do not have any problem. One more note the only relevant track rise from 1000ft Hope this helps

With -2000 of VS (I had forgotten this detail)

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I have tried this on A321 and it is amazing this table works perfectly. Just one thing though during descent and approach I found 2 related tables. The big one (first one which tells u to descend to 3000) and I think then it will be manual approach. And there is another small table (below) as ‘Approach and Landing Speed’ though the speed is already identified in the bigger table?

Thank you again in advance!😁

No problem! Glad I could help.

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