RC is very rewarding I have learned a lot in the last week but a few questions remain =)Sry to post this question now since it might take a while to put together a reply.I have a question which is probably not in the manual.In the real world which approach is most common?I am using the default B 737-800.I want to use the app that real world 737 pilots would use.When checking info on Navaid.com I see the following: -ILS or LOC -ILS -ILS(cat1-2-3) -RNAV GPS(Y RWY - Z RWY) -VOR/DME -VOR GPS -VOR-VisualWould be great if someone could give a quick explanation of the differences, like when they should be used and why etc. I imagine it would help others who check the post as well =)Tanks!Regards-William-

ILS is a LOC with glideslope (vertical navigation beam). This is preferred to LOC which only gives you a horizontal navigation beam and vertical navigation is performed by indicating altitude at known points measured by DME or other means. VOR/DME is similar but with much less horizontal preceision requiring a higher above ground MDA. The VOR is usually not directly aligned with the runway but is in the airport vicinity.VOR gives you the same less accurate horizontal navigation but altitude is timed from known points based on ground speed. This has yet a higher MDA. VOR/GPS is more accurate but not as accurate as a LOC for horizontal navigation. RNAV is similar to GPS with specified altitudes at known positions. RNAV aircraft equipment uses a combination of factors and RNAV waypoints can be placed anywhere. RNAV waypoints have a specified altitude for approaches but still is not as precise as an ILS,CAT 1, 2, 3 are the degree of precision available depending on aircraft equipment, airport equipment, and crew training. CAT 3 is a full autoland in zero visibility. CAT 2 requires a a close MDA (minimum descent altitude where the runway is seen or a go-around is executed. CAT 1 is similar but with a higher MDA.Visual is often preferred in VMC (visual meteorlogical conditions) of three miles forward visibility and downward I think of one thousand feet. The final approach phase would be entering a VMC approach pattern at some point of downwind, base, or straight in. This approach allows for a much shorter total distance. Pilots are required to conduct VMC approaches both day and night so many per quarter to maintain certified proficiency. In theory only general heading and altitude instruments are used without any radio navigation. The airport/runway must be in sight the entire time and the pilot is responsible for visual traffic separation.Pilots are also required to maintain proficiency in the various instrument approaches.The government authority sets the minimum proficiency requirements but airline policy usually dictates a "tougher" schedule in part due to insurance company requirements.Check www.stoenware.com for information about instrument navigation and other flight procedures.

Hi Ronzie!Thank you for the reply.I will do further research on approaches.Which of these approaches are most common for airliner jets such as the boeing and airbus families?RegardsWilliam

That can vary with conditions and how the airport and aircraft is equipped. The larger airliners are less maneuverable than smaller twin-props.As explained visual is often preferred to reduce approach time.The preferred instrument approaches are ILS (localizer with glide slope), RNAV (if aircraft is certified), LOC/DME, LOC, VOR/DME. An LOC may use DME from a nearby VOR or DME only transmitter. In this case one NAV radio is tuned to the LOC and the other to the VOR or isolated DME for distance.In the US RNAV approaches are just starting to get published for the largest airports.In order of ILS preference is usually CAT 1, CAT 2, CAT III with the last used in zero visibility conditions. Very few runways have CAT 3 approaches and they are usually found where fog is prevalent such as Boston with its frequent coastal fog problem. Frequently only one runway may be set up for CAT 3 since in fog there is minimal wind, a condition required for fog to exist and therefore wind is not contributing to runway choice. Usually a small amount of visibility is required for taxi operations. CAT 3 runways are required to be longer, I believe, than other categories to allow more tolerance in the landing zone and stop distance for roll-out.Some airline policies also dictate that anywhere from 1000 to 400 AGL the aircraft be manually flown visually with or without instrument guidance when possible. Autolands are only for the worst cases. One airline here in the US demands manual control (MCP then yoke/stick) below 10,000 feet AGL.Note that some of the larger aircraft fly into airports where due to terrain or proximity to other airport traffic patterns require procedure turns. So keep your hand-flying skills current.You might wish to look here at this index for on-line study material:http://www.faa.gov/library/manuals/aviation/In hard copy it is useful to buy the terminal procedures and instrument flying manuals from amazon.com. the Terminal Procedures manual relates especially o large airports and airliners. They are about US $14 each and I find these very useful as they go into all portions of controlled flight and planning. The terminal procedures book has more illustrations.

Thank you Ronzie!Once again your reply is very helpful! =)it would be great to understand under ehat conditions each approach method is used and on what basis the captain choses his approach and landing. I want to fly each route as realistacly as possible of course =)How ever right now I am only using the default 737 which does not fly or handle very realistacly and I can even start the darn thing from cold and dark porperly. I am waiting for the PMDG 747 and 737 for fsx to be available on dvd/cd and also the level D 767.RegardsWilliam

I listed the approaches in preferred priority. The choice is based on weather first to determine VMC or IMC, runway conditions, airline and crew capability, aircraft maneuvering capability, and then airport resources. Airline policies can enter into it to. It comes down to the most efficient means of getting down safely, and what ATC allows/directs.RC will assume an ATC controlled instrument approach unless you request a visual for VFR or your own instrument navigation requesting IAP for IFR conditions.

The idea of an approach is to get aligned and visual with the runway. On a nice day this can be done just by looking out side and flying visually to the field. On a crap day you need an instrument approach.Given that we need to be aligned and get visual, the best instrument approach is the one that has the most accurate lateral guidance and the lowest minima. This means that an ILS is always the best approach in IMC if there is one available. An ILS is good enough for the autopilot to land off with no visibility (in certain circumstances.) The RNAV approaches are the next most accurate and may have a lower minima than a VOR so they are the next preference. Next in line is the VOR because it is more accurate and easier to fly than an NDB. The NDB is the last choice.In practice, if an instrument approach is required and an ILS is available, always take the ILS unless you want to practice a different approach.Another thing going for the ILS is that they are the easiest to fly.

William,You stated the following questions in your original post:"In the real world which approach is most common?""I am using the default B 737-800.""I want to use the app that real world 737 pilots would use."What I think may be confusing you is WHO DECIDES what approach the pilot will end up using. When you are talking about a B 737 pilot (as you did above), it isn't normally the pilot who makes the decision. A pilot flying a B737 is going to be in contact with ATC during the entire flight, including the approach and landing to an airport. This is the way it is also done in Radar Contact.ATC will decide which approach to use depending on many circumstances. If the weather is IFR, then ATC is going to issue an Instrument Approach, like an ILS, Localizer, etc. If the weather is relatively clear and the pilot is able to see the airport and runway from a reasonable distance, ATC may issue a Visual Approach instead (the pilot must FIRST say he either has the airport in sight, or another aircraft that has already been cleared for the SAME Visual Approach which the pilot will agree to follow to the SAME runway). The key to all of this is a pilot may REQUEST any approach that is available, but ATC can DENY it and issue a different approach that the pilot then MUST follow, barring any extenuating circumstances. ATC is the final authority on what type of approach the pilot will make. Of course, ATC cannot force a non-instrument rated pilot to fly an Instrument Approach like an ILS...that would be illegal for both ATC and the pilot. But ATC will in almost all cases of commercial aircraft be the final say on which type of approach the pilot will end up flying.In Radar Contact, most flights are assumed to be IFR flights, like a B737 flight would be. Thus, ATC is going to issue the pilot an approach to do. Radar Contact *allows* the pilot to request a different approach, and I have never encountered a time in Radar Contact where this request was denied. So there is a "realism" factor that is being fudged in Radar Contact in this regard. For instance, if the Radar Contact ATC issues you an ILS approach, then you request a Visual Approach instead, ATC will simply authorize the visual approach with no further questions asked.In the real world, many busy commercial airports use Instrument ILS approaches even when the weather is VFR. This permits a regulated traffic flow and assists ATC in maintaining aircraft separations. Visual Approaches can be and are also used for the same reasons. But the key to remember is ATC makes the FINAL call on what type approach the pilot will fly. And unless the pilot has a very good reason for NOT wanting to fly that approach issued by ATC, the pilot is expected to fly it.After saying all of the above, from a real-world perspective, the two most common types of approaches you would encounter in a B737 would be an Instrument ILS Approach, or a Visual Approach. But the Visual Approach would only be issued once the aircraft was no longer in IFR conditions...in other words, the pilot had descended below any clouds and could see the airport from a distance far enough away to conduct the Visual Approach safely (or had agreed to follow another aircraft that had already been cleared for the same Visual Approach...in this case, the pilot does NOT have to have the airport in sight...he just follows the preceding aircraft, who already reported having the airport in sight, to the airport/runway.Hope the above helps.

Small nitpick. The captain is the final authority on anything the aeroplane does. The pilot can REQUIRE a particular approach and ATC would be obliged to provide it. This is unlikely to happen unless there's an equipment failure or something. In practice, it is as you say.>The key to all of this is a pilot may REQUEST any approach>that is available, but ATC can DENY it and issue a different>approach that the pilot then MUST follow, barring any>extenuating circumstances. ATC is the final authority on what>type of approach the pilot will make. Of course, ATC cannot>force a non-instrument rated pilot to fly an Instrument>Approach like an ILS...that would be illegal for both ATC and>the pilot. But ATC will in almost all cases of commercial>aircraft be the final say on which type of approach the pilot>will end up flying.

Absolutely. And that's why the section you quoted above contained the part that said, "...barring any extenuating circumstances." ;-)

Sorry, missed those words.

Falcon, if you are required to use a Star during appoach, at about what point will ATC start vectoring you to the FAF?Dave F.

>Falcon, if you are required to use a Star during appoach, at>about what point will ATC start vectoring you to the FAF?>>Dave F.There is no definite answer to that. Also, it is important to realize that you may NEVER receive a vector from ATC if the STAR connects to a FAF for the runway ATC is using at the time. See this link for the TYSSN ONE arrival to KLAS (Las Vegas McCarran):http://204.108.4.16/d-tpp/0713/00662TYSSN.PDFNote there are 4 "transitions" for the arrival (DRAKE, KINGMAN, LRAIN, and PEACH SPRINGS). Whichever transition you arrive on, they all will eventually take you to TYSSN. Thus the narrative says, "From TYSSN WP via 324 track to SUZSI WP, thence as depicted to PRINO WP. Rwy 25L, intercept the Rwy 25L localizer." PRINO is a FAF for Rwy 25L, so in this case, you would never receive an ATC vector to a FAF. Many STARS are flown this way. The CIVET 5 arrival to KLAX runway 25L is another example.If Rwy 25L is not the landing runway, then the narrative says, "All other runways, expect radar vectors to final approach course." In this case, ATC would give you vectors to a different runway so you could join the ILS, etc, outside of a FAF for that runway. Note this vector could start ANYWHERE along the STAR route to help ATC get the traffic sequenced correctly. The vector could easily occur before TYSSN WP if needed to maintain good traffic flows.In any case, "WHEN" ATC decides to start vectoring you depends on many factors...traffic loads, runway configurations, weather (thunderstorms, etc)...the list can go on and on. There is no "definite" time frame. Hope this helps.FalconAF