Continuing on from my last post (Climb & descent) you got your first taste of D.S.T and hear me talk about it heaps. So what is D.S.T? Distance / Speed = Time. A simple formula that will answer literally any en-route nav question you have!
How fast am I going?! ( DIST / TIME)
How much altitude do I need to lose?! (Vertical DIST / TIME) *last post’s formula
Now, I understand how confusing this is but here’s something that changes that!
Cover the item that you wish to find
Say it was distance, you have 2 remaining letters below and a X ( multiplied by) symbol so what do you do? (Speed X Time) it’s as easy as that!
Before we get into some worked examples it is important to know that every time we X we must divide the end result by 60, and every time we / we must X the end result by 60 (unless finding TIME in HRS). I’ll show you what I mean.
Let’s say that we want to find out speed. The things we need to have are (DIST and TIME). So, we’ve traveled 59nm in 12 mins our speed is? 295kts. “But why did I get 4.91?!” That’s because you didn’t X by 60.
Ok, let’s try one more.
If Travelling at 175 kts, how long will it take to travel 245nm (in mins)? Ans: 84 mins
Remember, if you want hrs leave the 60 alone. This question however, is asking for mins.
One last thing that may help solidify your understanding is that You can change the “D” to anything you like.
Just change the speed understand the “S” as rate.
If I missed anything or have any questions, let me know✈️