1. How do you determine cruising altitude when flying GPS direct?2. When do you start decent to IAF? Do you enter the 25nm zone before the decent or do you actually goto a transition waypoint before start decenting?Your comments are greatly appreciated.

> 1. How do you determine cruising altitude when flying GPS direct?It depends on what you're flying. GA VFR uses the ONE rule (Odd, North, East), meaning eastbound you fly 3500ft, 5500ft and westbound 4500ft, 6500ft and so forth. For heavy iron the RVSM is the rule in most of the world with even flight levels westbound and odd flight levels eastbound. Of course, there's much more to it - like weather, distance and airspace.> 2. When do you start decent to IAF? Do you enter the 25nm zone before the decent or do you actually goto a transition waypoint before start decenting?Again, that depends on what you are flying. The general rule of thumb is the "3 to 1 gouge": Take your crusing altitude, take the altitude at the IAF, subtract them and multiply by 3. Obviously, ATC will tell you when to descend and you you should follow their requests.Hope this helps,Pat

Thank you for your comments. I was more looking for how to select a cruising altitude to make sure not to hit any obsticles. Same for decenting to the IAF of an uncontrolled airport. My questions have more to do with avoiding obsticles during those stages of flying.

Get a set of used sectionals from your local airport or buy them online, along with an airport/facility directory. Cost $0, if your airport gives them away for free or $20 new.Good luck!

You need charts for that. VFR charts (sectionals) have obstacles and terrain dipicted on them and IFR Enroute/SID-STAR's/ IAP's usually have minimum enroute altitudes as well as MSA's (minimum safe altitudes) for certain approach areas, etc. IAP's, SID's and STAR's usually contain some obstacle avoidance procedures which are usually built in to the arrival, departure and/or approach.That's kind of a loose explanation but it should get you started.

You would need a real world sectional VFR chart for that. Most pilot stores give the expired ones away.

Getting the charts is the best way to go, but another tip is that the altitude suggested by the default flight planner in FS2004 is the lowest legal altitude that will give you terrain clearance. In other words, fly at least as high as the planner suggests and you'll be OK.-Gary Letona

That's good, thank you. What about transition to IAF?

Here are a couple great links (someone else linked to them, and I 'jumped' on them) to download charts on'line. It does take some time, but well worth it.Although I have paper charts (outdated), I took the time to download all these and now use my laptop as an 'electronic flight bag' during flights.1) Sectional charts for the US (download the .tif's):http://aviationtoolbox.org/raw_data/FAA/sectionals/current/Great for VFR flying2)Terminal charts for each state (complete) in PDF form:http://aviationtoolbox.org/munge/plates_by_state/...I converted the .tif sectionals into .gif's and view them in PhotoshopThe PDF's can simply be viewed in Adobe Reader

The transition to the IAF from the end of the STAR most times or should be depicted on the arrival chart or the approach chart. Sometimes it's merely a vector from the STAR termination point to "an" IAF (sometimes there can be more than one IAF also), other times the waypoints actually lineup depending on the arrival and approach you've selected.Hope that helps a bit.

Great. I just follow the STAR chart. Thank you.

Like others have said.. get a sectional.Draw a line from your starting point to your destination.Then read the big 2 digit number like 16(six will be smaller than the 1) in the square boxes of the sectional where your line goes through.http://skyvector.com/The default sectional there is Seattle area... look at that 28 (South of KSEA airport)..which means 2800 feet minimum for obstacle clearence in that square ...then look at the right.. where there are mountains.,,,, notice the 63 and 65..denoting 6300 and 6500 feet.then pick the next highest odd (7000 in that case) if going east (Easterners are odd people) then add another 500 (for VFR). so 7500 feet Thats your minimum altitude....upto the right edge of that sectional on your screen.IF you are going to further east.. you would notice those numbers increasing, 79 and 98 etc...MannyBTW.. if you are flying IFR ..enroute.. then transitioning to an IAF... well ..then you need an IFR enroute chart that would give you that MEA (Minimum enroute altitude) that you have to file as your minimum altitude for enroute until you hit that IAF. Whatever ATC gives your as your altitutde you cannot descend unless...ATC that is vectoring you, gives you a lower alitutde.For IFR... GPS... you could file for direct...and the minimum altitiude is by looking at sectional charts like you did for VFR then file that alititude and hope you get cleared for it.what you see as minimum altitude in a STAR is not an altitude that you can descend to. They are minimum altitude... but unless ATC clears you for that.,. you cannot descend to it.. Which is different from your Approach plate.. Once you hit the IAF of an approach plate and they have cleared you for that approach, you can descend to the miniumum as per that approach chart.Your STAR is no different than your enroute. Don't mistake your STAR plate alitutide like your approach chart altitude. STAR and Enroute charts minimum altitude are only minimum FYI. But you have to fly your ATC given altitude no matter what the STAR/enroute tells you. STAR/and Enroute chart clearence are for your lateral navigation.. Your altitiude clearence is seperate from whats set as minimum in those charts. When they clear you for a STAR.. it means..only lateral navigation and Altitude restrictions. There is one exception and ATC phrasology that allows you to descend to the STAR altitide .. I think its called "Cleared through"??? STAR-name.. I forget..Dang!.. I need to go refresh my memory.Here is a good story boarding.. How to STAR.http://www.planesimulation.com/stars.htm

Very clear explaination. Thank you. Guess I have to take the time to plan the whole flight.

Just for closure of my earlier post:Here is the difference in the way ATC can clear you for a STAR.1. Cessna 988AC, cleared via the ABC arrival."or 2. Cessena 988AC, descend via ABC Arrival."In the first case... you are cleared for the STAR for lateral navigation. But, you continue flying the last given altitude until the time they give you a new lower altitude which they would eventually.In the second case... you are cleared for the STAR for lateral navigation and you are also (implicitly) given a "descend at pilots discreation" up tothe minimum altitude mentioned in the STAR. You also have to comply with Min Xing altitude and min speed restrictions that may have been specified in the Arrival chartManny