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puttaround

ATC and Assigned Runways

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Okay, complex topic.Some rules:(1) In FS2004 and FSX only parallel runways can be in operation at the same time.(2) Aircraft engine type and weight have an impact on runway selection - if possible jets will be assigned to runways over 7,000 ft in length for takeoff. Turboprops will be assigned to runways over 5,000 feet in length. Piston aircraft are assigned to runways over 3,000 feet in length. In FSX the number of piston and turbo prop engines increases the runway length criteria. For example at KROC in FS2004, the Baron will be assigned to takeoff on the Rwy 7/25 which is 4,394 ft long. In FSX it will be assigned to Rwy 10/28 while the single engine piston aircraft are still assigned to Rwy 7/25.(3) Engine type and weight have an impact on landing runway assignment - but the way many AI aircraft are made, they are too light. AI use empty weight which should be set in an AI aircraft to a normal landing weight. For example the AIA B757v2 has an empty weight of 74,000 lbs - so FS rightly treates it as a small regional jet or biz jet.(4) Aircraft are assigned for takeoff to the runway with it's centerpoint closest to the pushed back position of the aircraft when it ask for taxi clearnance - as long as engine type and weight criteria are met. There is an extended runway centerline which owns aircraft in that cone. Doesn't impact most aircraft, but does at some airport.(5) Aircraft are assigned to land on the runway closest to their departure airport, unless the aircraft is coming directly in on a runway true heading - less than 1 degree variance. ILS Approaches written in the code for the airport may impact landing runway assignment - especially in IMC conditions with visibility less than three miles.Again - these rules are only operable when multiple parallel runways are present and open.Now let's look at KRICThree runways:2/20 - 6,612 ft7/25 - 5,322 ft16/34 - 9,007 ftNone are parallelILS on both ends of Rwy 16/34ILS on Rwy 02That tells me that Rwy 16/34 is going to be the active runway at KRIC almost all the time.FS uses the FAA "Light and Variable Winds" standard for runway assignment - so unless winds climb over a threshold - the runway assignment will not change - normally 10 to 15 kts.Now your saved default flight may be setting your runways. Unless you download real world weather, and then force a reload of AI, either by advancing the sim rate to 8X or more, or going to the Map View and changing you aircraft heading by 1 degree - your runway assignments are based upon the weather in your saved flight.A runway must have no AI aircraft in the active AI zone for arrival and no AI aircraft within 15 minutes of takeoff to change the active runway. (FS2004, FSX does away with this rule - but that can result in head to head takeoffs and landings).

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This is something I posted on another forum a couple days ago: FS hard rule - only parallel runways may be used at the same time.Our cheat - we use AFCAD to create very short fake runways no more than 7.9 degrees true heading apart to bridge the gap between physical runways. Place the fakes near 70 degrees north, or 65 south. Then we reorder the airport runway order in AFCAD, and if necessary the NAVAIDS, so the runways are in a sequence order from top to bottom - no two runways, real or fake, more than 7.9 degrees aprat on their true heading.Inherent problems - (1) Aircraft are normally assigned to land on the runway closest to their departure airport. There are some rules about short runways and weight - but most AI aircraft are woefully under weight in their flight dynamics - so FS properly sees the AIA B757 as a regional jet weighing only 74,000 lbs. The user aircraft is a little easier to deal with the runway assignment / length issue. But this weight issue will put a lot of AI landing on undesired runways at some airports.(2) There are only TWO allowable runway usage configurations - basically at KOAK AI will land and takeoff on Rwy 9R, 9L, 11 & 15 or they will land and takeoff on the opposite ends. This will result in some strong tailwind landings.(3) ATIS is basically useless because all the fake runways will be listed.(4) For the user aircraft, you have to learn how to ask for alternate runways for takeoff, and for landing. For landing, you first ask for an alternate approach, then ask for the alternate runway.

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Now, let's look at Patrick's KRIC - the AF2_KRIC.bgl which comes with his package.It has added fake runways to make Rwy 2/20 and Rwy 7/25 parallel, but not Rwy 16/34. That would not change the basic tendancy to use Rwy 16/34 as the active most of the time.I don't see an AFCAD file on Avsim which has all the runways active at the same time.Remember, you could only have Rwy 2, 7 and 16 active at the same time at KRIC, or 20, 25 & 34. That would of course result in frequent tailwinds and crosswind landings.One guestion, have you check to see if you have other runways available for takeoff?

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Okay, I've found an error with the runway headings for the fake runways in the AF2 file supplied with the scenery, which will cause only Rwy 02/20 to be used most of the time.Which AFCAD file are you using - that one or a custom one?

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Reggie, thanks for the detailed answers. I'm using the AFCAD that came with the scenery and the problem is, that runway 2 is always the primary runway used. I had a problem with a flight last night from KRIC to KCLT where the ATC had me take off from runway 2, make two turns, but only vectored me to a heading that eventually was taking me nowhere near Charlotte. I felt if I could take off from runway 16 it would be more in line whith what is done in real life. Most of the time when you take off for destinations south of Richmond, you take off from runway 16 not 2. This is what I was trying to get around. Again, as the set up is now, I'm always directed to land on runway 2 (or take off from runway 2) regardless of what direction I'm approaching or leaving Richmond from. As a matter of information, i mostly fly the boeing 737 or the Embraer 145. Thanks again for taking the time to help me with this, with such detailed answers. Bill

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Youf flight yesterday was a different issue.Your flight plan probably had the RIC VOR as the first waypoint.The Low Altitude Airways FP I just generated has RIC - MATOX - DALTO - that is three waypoints in the first 25 miles - and you have to fly over each of them in turn to make the FP work.The High Altitude Airways FP has RIC - ZITTO - that first intersection if 47.5 nm from the VOR - so you have time to make the turn - but you still must fly over the RIC VOR to make the FP work.The VOR to VOR FP has RIC - LVL - LVL is 50 nm from Richmond.After you create a FP, always check for waypoints within 30 nm of your departure airport - you probably want to delete those because they can keep you under local tower control until you turn enough to cross over them.Whenever the ATC seems to be sending you on a bad course - engage the GPS model of the autopilot and see what waypoint the ATC need you to fly over.

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Reggie, thanks for that information on flight planning. Another question, after discovering the error in the AFCAD that came with the add-on scenery, what was it, and is there something I can do to correct it? I have limited knowledge of the AFCAD utility but if its something rahter simple to correct it, I'll certainly give it a try. Thanks again, Bill

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Ah Bill,If you'd stuck with the small stuff none of this would have happened. But you had to go all "Heavy Metal" on me...Good to see you're still flyting! And Reggie will get you setup so that Richmond flows as it should.All the best from La-La land,Lance

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