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Guest vernonb4

STARS vs. IAP

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Guest vernonb4

Just when I think am beginning to catch on to things I find there is now something called an IAP (Instrument Approach Procedure)Will someone kindly explain what the difference is between a STAR and an IAP and when does one use which one !! Vernon Bown

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Guest stang

>Will someone kindly explain what the difference is between a>STAR and an IAP and when does one use which one !!Hi there VernonThe STAR is a set of waypoints used to get you from an airway to close to an airport. The IAP is a set of waypoints that take over where the STAR ends. They generally take you from where the STAR ends to right down to the runway and include the procedures for a missed approach. STARs usually are not specific to any runway while IAPs are designed for a particular runway.In order of use, you use the SID to leave an airport and connect to the airway you want to use. Once you get near your destination you then use the STAR to get you down close to the airport and finally you use the IAP to actually land the aircraft. Selection of the SID depends on which runway you depart from and direction you want to go. Selection of the STAR depends on how you want to approach the airport. For example if landing on runway 27 and your route comes from the North then you would pick the STAR that best connects from your airway route and swings you around to best connect up with the IAP for runway 27. As mentioned before you pick the IAP that is made for the runway you want to land on.Hope this helps.RegardsTerry

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Guest vernonb4

Thank you, Terry, That was very difinative and helpful. The best way is to try it out under various circumstances.. Vernon

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Guest hlm65

To complete the excellent summary by Terry, I could add that:not always are STARs available for any airport/runway while normallythere could be many IAPs for a single airport and even different IAPs for a single runway: you can have a (say) Rwy 36 ILS IAP, a Rwy 36 NDB IAP, a Rwy 36 VORDME IAP, a Rwy 36 VOR IAP, a Rwy 36 RNAV IAP and so on.The IAP are procedures drawn to take correctly an airplane flying IFR from the final(s) point(s) enroute (these could or could not be part of a STAR) to the inital approach fix for a determined approach type to a given runway. In a IAP chart you'll normally find a plan view and a profile view, the latter giving the correct descent slope. You'll find also much more information in a IAP chart, such as mimimums for a particular approach (visibility/RVR/decision altitude or height), missed approach directions, "some component out" (such as G/P u/s in a ILS approach) limitations, time from FAF to MAP, frequencies and so on.Hope this helps you.

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Hi,Three questions:I am also just learning how to use SIDS and STARS. If you use FSBuild or FSNav to automatically create your route, will the STARS used by these programs include the relevant IAP or is that a seperate matter?Do the STARS included in the FMC include IAPs?Or is it better to create the route and export it to PMDG without the SIDS/STARS and just choose the relevant SIDS/STARS from within the FMC on the DEP/ARR page?Thanks in advance for any advice given.Renzo Nicoletti


Bill Miller

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Guest pagotan

Renzo,I do not think it would be useful to start a debate on the merits of FSBuild versus FSNav. Both applications have their fans. So let's try to define a generic answer to your question. You basically need three things to prepare your flight: 1. A flight planner which can be FSBuild or FSNav or any other good one including some online flight planners. 2. A set of current charts for your airport of departure and your airport of arrival. Enroute charts are also useful.3. Either a weather addon or access to current weather datas.Ideally you would create a flight plan without SID STAR or APP then you would check the weather conditions at your departure airport and determine the adequate runway for take-off. When you know which runway you are going to utilize then you chose the appropriate SID and transitions to reach the first waypoint of your route. The next step would be to make the necessary entries in the FMC. I guess you could also create this "partial plan" (No STAR or arrival runway yet) with FSBuild or FSNav and export it to the PMDG FMC if manual input in the FMC is not your cup of tea.At time of descent you will then check weather conditions again, determine the runway for arrival and check on the charts which STAR, transition and approach are suitable. Finally you need to introduce these in your FMC.Things can be different if you fly on-line or with any other kind of ATC guidance. In this case you may or may not be "vectored" which means that procedures may become redundant and therefore only the "route" segment of the plan is relevent.I am sure there are many other ways to enjoy a good flight and other users may prepare a flight differently but again I specifically said at the beginning that my description would stay generic in order to preserve the merits of the two applications you mentioned in your post.Hope this will help.Michael

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Thanks for the helpful advice although I don't think my post asked about the respective merits of FSNAV and FSBUILD but merely stated that I have both programs.However, there is still a matter I am unsure about and apologies in advance if your post has already answered my question:I have heard about SIDS/STARS, IAPS and now you mention transitions. In the PMDG FMC, I see SIDS mentioned on the DEP/ARR page but not IAP's. In FSNAV and FSBUILD, I see SIDS/STARS but not IAP's. Therefore, is it possible for a STAR to include the IAP and that is the reason I do not see IAP separately mentioned.Finally, is an IAP the same as a transition?If this is all too much to explain, perhaps someone could point me in the direction of some good literature I can read.ThanksRenzo Nicoletti


Bill Miller

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Guest pagotan

Renzo,Have a look at this thread:http://forums.avsim.net/dcboard.php?az=sho...75067&mode=fullIf you scroll down to the second third of the thread you can read a post I wrote earlier today describing the different segment composing a route gate to gate. This post addresses the transitions in connection with both the SIDS and the STARS. Again you should rely as much as possible on current charts for the airports you are flying in and out. The procedures database available for the FMC are not always complete and transitions may or may not be included. If they are not but you find out that your plan should include some according to the charts you have, then you can always punch the appropriate navaids of the transitions in the FMC (with speed and altitude restrictions).By the way, this is where an application like FSNav becomes handy. If you enter the same waypoints in FSNav as the ones you entered in the FMC you can visualize the planned route and check its correctness at least from a graphic point of view.Michael

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Guest Papa November

>Finally, is an IAP the same as a transition?No, it is not the same. "Transition" may have couple of meanings.1. Transition in SID means a different part of the same SID with common first part of it. 2. Transition in STAR is a common part of two different STARs. E.g. route of STAR(a) and STAR(b)lead to the common point (fix, navaid) but this is not IAF. From that point there is a common route leading to IAF where STAR ends.3. Transition can be a specific approach procedure (very common in German airspace (e.g. EDDF, EDDM, EDDT). These procedures have been created to allow flowless and safe traffic handling by ATC. Piotr

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Guest frankathl

"2. Transition in STAR is a common part of two different STARs. E.g. route of STAR(a) and STAR(b)lead to the common point (fix, navaid) but this is not IAF. From that point there is a common route leading to IAF where STAR ends."Hi Piotr,I'm not sure the above is correct(?) Rather, STAR transitions provide different entry points from the enroute portion of flight into the STAR procedure. At the other end of the STAR you can also have transition points(VIAs) connecting to approach procedures for different runways.See the enclosed diagram.BR,Frankhttp://forums.avsim.net/user_files/105520.zip

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Thanks for the diagram frankathl although in some respects I am more confused than ever. I have just started flying on Vatsim and this is why I had better start understanding this stuff in case ATC give me an instruction I don't understand. But now, I don't just have SIDS and STARS, butSID/STAR transitionsIAPSVIA'sSo, 1. I have my route planned into FMC2. Weather check/ATIS tells me which runway to takeoff from3. I choose a SID from FMC DEP/ARR page appropriate to the runway which sends me in right direction for the first NAVAID in my flightplan.(or let FSNAV etc choose SID for me)4. Now, where do I get the transition from, FMC? If the FMC doesn't disclose one, do I manually link the end of the SID to the first NAVAID in my flight plan?Perhaps someone knows of a step by step tutorial about this I could use.RegardsRenzo Nicoletti


Bill Miller

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Let me try and help Renzo but bear in mind that SID & STAR can vary between the USA and Europe.Normally a SID will be named after its last waypoint. So if you have developed your en-route part of the flight you will know the start waypoint, that waypoint should be the same as the end waypoint of the SID and therefore the name of the SID.Next you determine which runway is in use and select the specific SID which goes from that runway, this will add 2 digits to the end of the SID name.Let's take a real World example by using charts from Finland and assume we are using Rwy04 either 04L or 04R.http://vacc.fi/downloads/charts/Click on the 'I have read the text and I accept the restrictions' to access the chart download page.Scroll down to EFHK and save the charts for SID(Jet)04L & SID(Jet)04R, also RNAV Transition for 04L & 04R Let's say we are departing to the North West.If you look at the SID for 04R you will see an intersection PIVAK to the NW of EFHK. This should be the first waypoint of your en-route part of your flight. As explained above the SID is named after its end waypoint.On that chart you can see that the SID is called PIVAK 3D.If you now look at the SID chart for rwy 04L you will see the same intersection (PIVAK) but the SID is now called PIVAK 1P. Those last 2 digits change as the runway changes.The same applies to STARs.Looking at the RNAV chart for rwy04L and arriving from the West there is an intersection LAKUT and the STAR is LAKUT 1T, for rwy 04R it has changed name to LAKUT 3A.If the SID's & STAR's have been correctly designed in the FMC database all you have to do is select the departure runway, this will give you a list of SID's for that runway. Scroll down the list until you reach PIVAK, you should only see PIVAK 3D if you selected rwy 04R.Similarly if you select rwy 04R for arrival you should only see LAKUT 3A.If the ends of your en-route part of the flight do not fall on a SID/STAR waypoint then you will have to modify the ends of your en-route part so that they do, usually by changing the airway.As for flying on VATSIM you should always enter the SID and STAR in the FMC so you can fly them should there be no ATC available.However if ATC is available the controller will give you the departure SID and if it is different from that which you included in your flight plan he will ask you to correct your flight plan.For arrival it is usual for ATC to vector you in, as was mentioned by another poster. For this all you do is override the FMC route by using the MCP to change heading and altitude. Just make sure the radios are set to the correct ILS frequency.Also be aware that on departure ATC may give you a short cut on the SID by saying 'Direct to XYZ'. Just call up the legs page, select XYZ waypoint, put that at the top of the legs page, activate it and execute it, the FMC will then fly to that waypoint.Hope that helps.Dave

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Guest Papa November

Definitely you are right!Piotr

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Thanks Vulcan. I have printed out your comprehensive reply for future reference.


Bill Miller

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