MAY 2010 Theme Flight #1

[Norberto Rivera]

sorry sergio i forgot all about that old beast.....hmmmm maybe it will be on the tip of my tongue for the next theme flight.

And you're encouraging him!!!!

[Wayne Pierce]

I should have the old fashion way of calculating descents available to me.

Yep, you probably have one but here is an Old fashioned way of doing it. I use it.

Descent Calculation

For all those flight simmers and real life pilots who are unsure when to start descending and what descent rate to use, especially if you are at a good altitude, these calculations can help.. They are simple enough you might even be able to remember them when in the plane..

The first calculation is used to determine when to begin descending, the second gives you the rate of descent to use.

For these examples, I have used 10,000 ft altitude, and 120kt groundspeed.

1) To decide when to begin descending, take the last 3 zeros off your altitude then multiply by 3, which gives you the number of nm away to begin your descent. So, take 10,000 ft, knock the zeros off becomes 10, multiply by 3 becomes 30 nm away from your destination to begin descending.

2) To decide the rate of descent to use, divide your groundspeed by 2 then multiply by 10. So 120kt / 2 = 60, times 10 = 600 ft / min to descend at. Just remember your groundspeed is used, not your airspeed.

Use it or not. Copy to a text file and keep it with your flight files. You never know when you may need it.

WLP

[Greg Gemelli]

PLL275065= PLL 275 deg radial at 65 dme

Cheers

[Norberto Rivera]

Thanks Wayne. I learned something new today. I knew about the feet of descent * 3, I usually add 10 just to be safe. This is the first time I've heard the rate of descent calculation though! I'll try it out on the GFI tonight.