Decent...

[JakesF14]

After a BIG miscalculation last night, resulting in a rapid decent, I was wondering what is the real life decent procedure in terms of your distance from your destination?

I've had this scenario:

Flying a 737-800 at 31 000ft from Cape Town to Mauritius (a weird thing happened - I ran out of fuel).
Anyway, I started to decent at 65nm before reaching Mauritius Int'l. But my decent rate was too small.

What is the correct decent rate,and where can I find more info?

[Brett_Henderson]

There's no set answer for that scenario..

But as a general rule, you can use the standard

[Brett_Henderson]

OH ! .. and don't forget winds aloft...

[JakesF14]

Thank you Brett.. I guess I'll have to practise that!! Actually I ran out of fuel with just less 1000NM still to go. But i quickly refuel (and I think it is an error on the POSKY 737-800, as the range of the 737-800 is over 3300nm, and the distance between FACT and FIMP is 2440nm.)

But I am learning......   ;)

[olderndirt]

Don't forget to factor in anything weather-related - holding, missed approach and/or having to go to an alternate.

[JakesF14]

Don't forget to factor in anything weather-related - holding, missed approach and/or having to go to an alternate.

Going to an alternate.. yeah I forgot about that!! A good thing I am not an airline pilot....yet!

[-Crossfire-]

I tend to use the 3:1 ration rule, which works well for most larger aircraft.

Cruise altitude - field elevation x 3 = natuical miles
If you are at 30,000 feet, and your desination airport is at 2,000 feet, that is 28,000 feet of altitude to lose.  28,000 feet expressed in thousands is 28.  28 x 3 = 84.  Begin the decent 84 miles back.

Now what should you use for rate of decent?  Take your ground speed, add a zero, and divide by 2.  Let's say you're grounding 400 knots, 4000/2=2000.  Start the decent at 2000 ft./minute.

[JakesF14]

Thank you for this valuable info! Really appreciate it!

[olderndirt]

Jake - couldn't resist.

[JakesF14]

[quote]Jake - couldn't resist.