Hi. As you know, Instrument Approach Charts(IAP) have some confusing words. I want to know what they are.There are 3 kinds of fixes, IAF, IF, and FAF. What's the difference?

In creating and charting approach procedures, the designers work in terms of "segments" which begin and end at fixes. Two segments are mandatory -- the final segment and the missed approach segment. The optional segments are the initial segment and one or more intermediate segments. The difference in the segments has to do with the assumed navigation accuracy of the aircraft, and the resulting altitudes required to ensure that there are no obstacles in the possible flight paths. As you might suspect, the initial segment begins at an Initial Approach Fix (IAF), an intermediate segment at an Intermediate Fix (IF) , and the final segment at a Final Approach Fix (FAF). Besides the segments, depending on the geometry of the approach a Course Reversal procedure may be required.

Well, I don't understand. So, is it allowed to start an approach from FAF or IF without passing IAF because the initial segment and the intermediate segment are optional?The second question is about DA and DH. I guess that DA is sea level altitude(MSL) by the atmospheric altimeter and DH is height from the ground(AGL) by the radar altimeter.So can I use either of them for the missed approach point? About RVR, first I thought that it is the distance from the MAPt for runway threshold or runway lights.But I calculated the distance = 200(DH) / sin 3deg / 3.3(for conversion from feets to meters) = 1165.5 meters, not 550 meters that is the correct RVR for the DH, 200 feets.I think I'm misunderstanding.It may sounds silly, but I don't live in the country where English are spoken, so please answer without using difficult expressions if you can.Thanks.

This link should give you all the info you are looking forhttp://www.navfltsm.addr.com/

Well... I think the site is lacking in explanation about approach segments...Does anyone know about them?

Hi,To get a better understanding of the different approaches and their design criteria (sounds technical, but stay with me) I suggest you head over to the ICAO Doc 8168. http://dcaa.slv.dk:8000/icaodocs/Doc%208168%20-%20Aircraft%20Operations/Read that and if you have any questions do not hessitateMartin

Hi. As you know, Instrument Approach Charts(IAP) have some confusing words. I want to know what they are.There are 3 kinds of fixes, IAF, IF, and FAF. What's the difference?Well, I don't understand. So, is it allowed to start an approach from FAF or IF without passing IAF because the initial segment and the intermediate segment are optional?The second question is about DA and DH. I guess that DA is sea level altitude(MSL) by the atmospheric altimeter and DH is height from the ground(AGL) by the radar altimeter.So can I use either of them for the missed approach point? About RVR, first I thought that it is the distance from the MAPt for runway threshold or runway lights.But I calculated the distance = 200(DH) / sin 3deg / 3.3(for conversion from feets to meters) = 1165.5 meters, not 550 meters that is the correct RVR for the DH, 200 feets.I think I'm misunderstanding.It may sounds silly, but I don't live in the country where English are spoken, so please answer without using difficult expressions if you can.Thanks.

For US procedures check out www.faa.gov for the Aeronautical Information Manual and Instrument Procedures Handbook... In addition, naco.faa.gov has downloadable explanations of instrument approach plates and maps.DJ

To get a better understanding of the different approaches and their design criteria (sounds technical, but stay with me) I suggest you head over to the ICAO Doc 8168. http://dcaa.slv.dk:8...t%20Operations/Read that and if you have any questions do not hessitate

Thank you for your information. I didn't know that the ICAO documents are available on the net.Now I know that the approach segments and fixes are provided for aircrafts to prepare configuration for an approach gradually.

2.2.3 The arrival route normally ends at the IAF.

Yes, it sounds normally. But how about exceptions?Please refer to the charts I attached.ARLON ARRIVAL ends at ARLON. But ILS RW34L Z APPROACH begins at CREAM, is the IAF, not ARLON that is the IF.Can I use this approach with ARLON ARRIVAL without passing CREAM?That is the question I've wanted to know.Thanks.

In normal real life operations ATC (or the Japan equivelent) would give you vectors to intercept the approach. In FS, you can use any fix, or even manually vector yourself. As long as you end up with a 30-45 degree intercept angle for the ILS, it really doesnt matter how you get there. You can intercept at a higher angle, but depending on the plane, it may overshoot the approach or 'S' turn to stabilize on it.