I know how to calculate my descent rate and when I should start descending, even though I do it correctly, I usually have to go around and start descending again. Is there another way to calculate your descent? Am I meant to be approaching the airport at a certain angle? Help would be appreciated. Thanks!
Hello my friend, search before posting.
This one is very good by Thomas Hense
How to calculate rate of descent.
Method 1 - Ground speed x 5. 3 will give you your required rate of decent for a 3 degree glide slope.
Example: GS 300kts, 300 x 5.3 = 1590. Since VS adjusts in increments of 100, you should round off to VS -1600. It is better to come in early and level off than coming in high and having to dive bomb the airport.
Method 2 - Some people multiple Ground Speed by 6,
Example: GS 300 x 6 = -1800. Again better to come down early and level off to your next waypoint or to the start of the glide slope. Some multiply by 5, but I always seem to come in high using 5.
Method 3 - Divide your ground speed by 2 and add a zero.
Example - Ground speed 300kts ÷2=150, add the zero for VS of - 1500
Method 4 - Start descent when the time to the airport equals altitude to lose for 1000 ft/min descent.
Example: 10,000 feet to lose, start descent 10 minutes out at 1000 ft/min.When you reach the ILS follow the ILS glide slope, using method one.
Method 1 is the most accurate, but you need to keep adjusting the VS as the ground speed decreases. Perfect for final approach.
Methods 2 is good for descending from 10,000 to 3,000.
Method 3 is very easy and gets you close to where you want to be.
Method 4 is useful when descending between waypoints when above 10,000 feet. I also use it between waypoints down to 3,000 feet above ground level.
All these methods require regular adjustments as your speed and time change.
Thanks for the reply. I know about this. I use the exact same method but sometimes end up missing the runway. That is what I need help on.
Check the post again :)
This one is the absolute easiest. You will always come in a bit early (because your speed decreases) and you will be required to level off or slow your descent. That is normal, you never want to come in to high. I use it every flight as well as between waypoints.
Of course you will be required to have a flight plan for any of the methods mentioned above. And in your instrument dock you will need “ETA to Next” and “ETA to Destination” if you are using time, and “Distance to Next” and “Distance to Destination” if you are using distance. I have all four including “Bearing to Next” in my instrument dock.
Use between a -3000 -2000 decent rate