approaching Top of Descent

[rowcoach 4]

Hello,Just a quick question. I'm flying the 737-500 with FS9. I've been trying to fly from CYYC to CYEG. As I approach the top of descent I get a message on the FMC saying that the PTH DES NOT AVAILABLE. Is there a step I'm missing as I get near the point where I want to start my descent? The only information I don't put in the FMC during pre-flight is the approach rwy as I don't know what that'll be until I get to the airport.Thank you in advance.Cheers,colin

[downscc 1,327]

The FMS is unable to calculate the vertical path, probably because it has an incomplete lateral path. You didn't mention if you have an arrival available and selected. As a minimum, you can put a fix at 40nm out and assign an altitude constraint of 10,000 to give the FMS something to base a descent path.Please sign your full name in this forum.

[rowcoach 4]

Thanks for the reply. I realized in my flight plan that I don't follow an actual approach plate - I just kind of cobbled something together. Is there an easy way to know which STAR's to use? Given that you are not assigned a runway to land on until you get closer to the destination airport (I am assuming the in the real world this is weather dependent), how do I know which runway to program into the FMC?Thanks again :( Colin Gray

[michal 44]

which STAR's to use? Given that you are not assigned a runway to land on until you get closer to the destination airport (I am assuming the in the real world this is weather dependent), how do I know which runway to program into the FMC?

In real world they DO know what runway you will be using (winds do not change that often) and hence they assign you STAR compatible with this runway. Yes, they may tell you runway/STAR and what approach to expect just before you reach your TOD or they may give it to you much earlier depending how confident they are about the weather remaining constant. If you are Virgin Atlantic 747 flying from Heathrow to San Francisco in summer months - you are practically certain of STAR/approach/runway the moment you take off.

[downscc 1,327]

Look at what the real guys are using by going to flightaware.com, under pilot resouces you can look at all IFR flight plans between any city pair (mostly US-only).The typical location will have four arrivals, each one arriving from NE NW SE SW. Each typical arrival has transitions that start at an enroute fix or VOR up to a hundred miles out or more. Plan your enroute to one of those transitions. There are many locations that are not typical (especially on the coasts), but you can sort it out by looking at STAR charts and actual flight plans.

[ExNusquam 11]

Look at what the real guys are using by going to flightaware.com, under pilot resouces you can look at all IFR flight plans between any city pair (mostly US-only).

I have found that Flightaware works for all of Canada as well. It also works for "most" European flights, you just have to type out the URL yourself. EX: http://flightaware.com/live/flight/BAW304