Top Of Descend: When Do You Start Your Descent? - [Calculations and Tips from an Airline Captain]

[@PILOTCLIMB]

Don't hesitate to comment below with your questions and thoughts!! Happy Landings!!

[@mjabbie7912]

Love your explanation, the way you talk makes it easier to understand Subscribed

[@PILOTCLIMB]

That's great!! Welcome onboard! Don't hesitate to ask me any questions when watching the rest of the videos! Have a great day!

[@gabrielbenjaminarg]

From Argentina, thanks. For your tips, to tell us your experient and of course explain very well the topic. You earned my subscription

[@charliebo_music]

Well explained. You made it easy to understand. Thanks.

[@PILOTCLIMB]

You are welcome! Don't hesitate to ask me any question you might have when watching the rest of the videos

[@conned]

Spot on!! As per fcom3. Of course,FMC gives you TOD fix based on LDW.also. Nice...

[@PILOTCLIMB]

Thanks for watching!!

[@stevehewitt4190]

Thank you again captain, now I might even look like I know what I'm doing in front of my grandson, up until now I have trusted my T/D to the FMC which of course as you point out could have the wrong input with a wrong output. Don't worry about your drawings its the subject that counts and it helped me a lot.

[@PILOTCLIMB]

That's awasome!!! I'm glad the video helped you to understand better the descent management..

[@gianlucaorru2737]

great explanation !

[@PILOTCLIMB]

Thanks for watching!!

[@jesusboquiren328]

Clearly understood thanks alot learning fast Capt

[@PILOTCLIMB]

That's great! Thanks for watching!!

[@Dylan-djcali420]

So a heavier ac requires a earlier Tod with a more shallow angle?

[@jakew9887]

Great presentation. Thanks

[@PILOTCLIMB]

You are very welcome

[@karimgaffar]

Great great video thanks alot cpt keep it up waiting for more videos👍

[@PILOTCLIMB]

You are more than welcome!! More videos to come soon!! Thanks for watching and the kind comment!

[@jay-rus4437]

Great info. For flight sim, since it isnt real life, I multiply ALT x 3, just as you showed, and then add 10 miles. Overall works well and gets me in range for the sim decent

[@gabrielbenjaminarg]

Could i ask why you add 10miles? Thanks for your explination

[@jay-rus4437]

@@gabrielbenjaminarg ….. additional distance for speed reduction.

[@Mariodingenen]

Is the speed the IAS or ground speed ?

[@PILOTCLIMB]

Pilots use IAS

[@SaurabhKumar-hr7fn]

How does the weight affect the track miles required?

[@PILOTCLIMB]

Hey, thanks for watching!! The heavier the Aircraft the more track miles are required.. Let me know if you have more questions 👍

[@sagardeepraj3344]

Hello captain thank you very much for your informative video. Want to know What is the reason behind taking 2 numbers from the altitude and multiplying by it 3 .. ?? Thank u again!

[@PILOTCLIMB]

Hey, thanks for watching and your support! I'm happy to see you are making all these questions! This shows you want to learn and this is great! The main reason why we do that calculation is that by doing this simple calculation you can have a good idea if you are on your descent profile! We only take the first two-digit because otherwise, the calculation won't make sense. Let me know if I answered your question..

[@sagardeepraj3344]

@@PILOTCLIMB I got ur point thank you captain..

[@nitram419]

@@PILOTCLIMB How about this method using high-school trigonometry which we all done in math class when we were kids: Track distance required in nm (horizontal along the ground): = [Altitude_in_feet / TAN(descent_angle*(Pi/180))] / 6076 Ps. The divide by 6076 at the end is to convert from feet to nautical miles. ?

[@PILOTCLIMB]

@@nitram419 Hey, thanks for watching!! For sure a more complete and precise calculation will be more accurate, however, when flying the plane we need to keep it simple and easy to calculate mentally. I wish you a great day!!

[@christopherwilson6527]

Do you ask atc to start descending, or is this all part of the flight plan and they already know when to tell you to descend?

[@PILOTCLIMB]

Hey, I hope you are doing great!! Many thanks for watching the video. The Top of descend is on the Flight Plan so the atc have an Idea of where it is located, however, you as a pilot, may want to descend early due to possible short cut or other factors, or ATC may ask you to descend early due to traffic. As you can see sometimes the pilots ask for descent and sometimes the ATC ask the pilots to descend. According to my experience 70% of the time I ask for descent and 30% atc instruct me to start the descent. Don't hesitate to ask questions when watching the other videos👍 I wish you a great day Gabriele Pilotclimb

[@christopherwilson6527]

Makes sense, thanks for the reply 👍

[@dr.celalettinucar]

Is not 1500 fpm very high for descend? if we have a tail wind and ias is 280 kt why we dont decrease the throttle and set the speed to 250 kt before step down which is illustrated on star charts... 🤔

[@PILOTCLIMB]

Hey, thanks for watching! The Rate of descent vary with many factors, so 1500 fpm might be very shallow or very high, it all depends on the Aircraft type and speed. For example, for a cessna 152 1500fpm is a high rate of descent however for a Boeing 747 is very shallow. You reduce the speed depending on your position compared to the ideal path. On Wed 14 of July I will release a flight Sim Video where I talk about this topic. Make sure you check it out!

[@ahmedsmart1120]

1)So when the altitude is FL300 and the airport has an elevation of 5000ft, i have to calculate (30000ft-5000ft) first and then multiply with 3, correct? In this case 75NM is the distance for the altitude. 2) is the speed in your example 280knts, indicated or groundspeed? And which wind of 30knts are you using for tailwind? Are you using the average wind or do you have to consider every windcomponent for every leg in your flightplan? 3) in case of sidewind, do you have to take the tailwind component for calculation? 4) in a comment to another user you wrote that the atc has an idea where you start your decend. But how exactly does it work? Thanks for answering.

[@PILOTCLIMB]

Hello, I hope you are doing great!! many thanks for watching the video!! All right let's start :): 1: All correct!! Very good! 2: The 280 kt is indicated since you use the indicated airspeed for flap extension. For the Top of descend calculation, you can use the average tailwind component that you will have during your descent. 3. in case of crosswind you simply disregard the wind since there is no tailwind or headwind component. 4. The Air Traffic Controllers can see on their radar your altitude speed and more information, so, the ATC is actually quite good on providing descend guidance, some ATC units (LONDON for example) are extremely good on managing the descents of the Aircrafts. I hope my answer helped you if you still have any questions don't hesitate to ask! Have a great day Gabriele Pilotclimb