# PMDG Fliers...help!

dailyflier Guest

When I'm flying, I understand the FMC will calculate my TOD and descend down the right path. However, how do I know what to set my MCP altitude to, and at which waypoints I should be at which altitudes. I heard somewhere that I should't be below the GS at any time during the flight, i.e. i should intercept it from above. Still, I very often overfly the r/w. Sometimes, I try to find the first waypoint which would be on my final heading, and I create a restriction of, lets say, 200/2500....Is that how I'm supposed to do it. Its kinda hard to phrase my question properly, but I sure hope I could get some help. Thanks, and have a great morning/day/evening

CRJCapt Chief Captain

I don't have PMDG 737NG, I'm going to install it soon but I want to print and go over the manual first. I can only talk in general terms.
The TOD in most FMC/FMS systems is set to have the aircraft at 1500 ft AGL at the destination. Some will descend at the TOD, most will not. Even on the ones that will descend, you need to set the altitude preselect to a lower altitude(like 2500 ft.) or it won't descend. IFR, ATC will give you descent altitudes. On your own, descend on a 3:1 gradient(30,000 ft -100 miles out, 15,000-50 miles out). Altitude(hundreds)/3=distance (300/3=100). You can descend before these altitudes but if you get closer, you'll have to use more extreme descent rates. Descend at 1/2 your ground speed, 400 kts-2000 FPM, 300 kts-1500 FPM.

Placing a crossing restriction, as you stated is good, just depends on the point you choose. I would place the point you stated (at a sea level airport), about 15 miles from the airport.

Normally, you intercept the Glideslope(GS) of the ILS from below. You should not be below the GS from GS intercept until DH(200 ft. AGL), not the entire flight. 🙂

dailyflier Guest

Thanks for that explanation CRJCapt.

I was wondering, do you think it would be possible to create a pseudo waypoint 15nm away from the airport, so as to place specific restrictions at it? Sometimes, I'll have a waypoint 30nm from an airport, then another waypoint 10nm away, with nothing in between.

Of course, I highly doubt this is what pilots do, but I may be wrong.

CRJCapt Chief Captain

dailyflier wrote:

I was wondering, do you think it would be possible to create a pseudo waypoint 15nm away from the airport, so as to place specific restrictions at it? Sometimes, I'll have a waypoint 30nm from an airport, then another waypoint 10nm away, with nothing in between. Of course, I highly doubt this is what pilots do, but I may be wrong.

You should be able to put a waypoint anywhere you want using P/B/D thats Place/ bearing/Distance. KDCA/328/15 for example.

In the real world, ATC controls the TOD location and all other descent points. Some pilots will insert a point at 30 NM/ 10,000 so that the FMC will warn you that you should be descending. If ATC keeps you above this, you can request lower. He may have forgotten about you, it happens when their very busy. 🙂

Solotwo Chief Captain

Its VERY complicated, and could be amazingly confusing to someone thats new to FMC's. I've dealt with quite a few of them and I finally have this one figured out. Its the best one I have EVER used.

The best way to learn is by a tutorial, and I'll link you to the best one.

http://library.avsim.net/search.php?SearchTerm=pmdg737.zip&CatID=root

Get that, print it out, and do the flight a few times.

dailyflier Guest

Solotwo, thanks for the good link. Please, allow me to quote one part of the manual

Go to the LEGS page and set the speed and altitude restrictions for every waypoint that requires it. If there are no
restrictions set for a waypoint, the FMC automatically calculates altitude and speed. The restrictions I want you to set are:
LUNAT - /260 (only speed restriction); NOAL - 13000/230 (speed and altitude restriction); TIEL - 9000/ (only altitude
restriction); XARA - 6000/190 (speed and altitude restriction); ERNA - 5000/ (only altitude restriction); EUJE - 3000/ (only
altitude restriction); LOBO - 2100/ (only altitude restriction). The FMC should set the empty fields automatically, but feel
free to override them if you don't agree to a FMC setting. This is what your approach should like like...

He tells me what all the necessary restrictions are, so as to get me at a reasonable altitude for landing. On my own, how am I supposed to figure out what the restrictions are, or do I improvise?

Solotwo Chief Captain

Either go by what ATC tells your or print out all the approach planes and STAR's and plug them in yourself, thats what I do. Also if your flying in the US download this...

http://library.avsim.net/search.php?SearchTerm=cycle0609_sidstars.zip&CatID=root

That will put all hte correct altitudes in if your airport has a star.

It just takes time, less then a year ago I just flying again and I could hardly fly a cessna and took me months to do a proper ILS landing. Now I'm flying all these complex birds with ease. Just keep doing flights you should figure out the quirks of the FMC and figure out how to use it to your advantage.

dailyflier Guest

So I guess I'll start trying to find some Approach plates 😀 Thanks for your help guys. See ya' round 😉

Solotwo Chief Captain

or

www.myairplane.com

Everywhere I fly I print out every diagram for the airport. Lets just say I have a huge stack of papers.

CrashGordon Chief Captain

Solotwo wrote:

www.airnav.com

or

www.myairplane.com

Everywhere I fly I print out every diagram for the airport. Lets just say I have a huge stack of papers.

I solved the huge stack of papers problem. I downloaded all the charts to my notebook. and display them there. Very handy.

Solotwo Chief Captain

Don't give me any idea's, this damn thing has cost me enough money already. 🙂