# Whats the landing formula?

Guest

Ok, i've managed to suss out Back Course ILS landings, now the runway i use doesn't have a glideslope to let me automatical glide down for a landing it must be done manually.

Now i remember there used to be a formula for landings. But i cannot find the information.

I.e. You was 'X' NM away from the airport at speed 'b' at altitude 'c'. It helps you to work out at what distance you should decend at your current speed and altitude.

It was a little multiplicaton formula or something.

Secondly what is the standard decent rate on the glide slope?

Joske

CRJCapt Chief Captain

3:1 for approximately a 3 degree angle, 300 ft per nautical mile.

Example:20 nm 6000 ft.
-----------15 nm 4500 ft.
-----------10 nm 3000 ft.
-----------05 nm 1500 ft.

Guest

Ok i've got what you've said great. So let me get this correct.

Say i am travelling at 3000ft on final approach for landing (in my 737), travelling 145kts approx 10NM miles away. Using the formula ground speed multiplied by 5, therefore my descent rate would be approx 725fpm.

Does this sound about right to you.

Sorry for all the questions.

CRJCapt Chief Captain

Anonymous wrote:

Ok i've got what you've said great. So let me get this correct.
Say i am travelling at 3000ft on final approach for landing (in my 737), travelling 145kts approx 10NM miles away. Using the formula ground speed multiplied by 5, therefore my descent rate would be approx 725fpm. Does this sound about right to you.
Sorry for all the questions.

Yes, that's correct. You can also think of it as 1/2 your ground speed.
145/2=725(forget the decimal)

Guest

Thanks for your time, CRJCapt. Really appreciate the help.

Joske

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