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Guest jshyluk

Runway slopes and takeoff performance

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Colleagues,One of my local airports has a longitudinal runway slope in excess of 2 degrees, so i'm after some info on how FSX (I'm still largely bonded to FS9) models such things. Therefore:1/. Does the standard terrain mesh of FSX show up runway slopes (in any direction) in general?2/. Do any of the add-on meshes around improve the situation?3/. To what extent (if any) does FSX - or any of the more advanced airliner add-ons available - model the difference in take-off performance for an uphill or downhill slope?4/. While I think of it, how about the differences experienced between wet and dry runways?Your thoughts appreciated,Andy

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>1/. Does the standard terrain mesh of FSX show up runway>slopes (in any direction) in general?No, all FS2004/FSX runways are flat, due to the flatten situation inherent to all MSFS editions to date.>2/. Do any of the add-on meshes around improve the>situation?Given the above, no - add on meshes do not influence the terrain within the airport boundaries.>3/. To what extent (if any) does FSX - or any of the more>advanced airliner add-ons available - model the difference in>take-off performance for an uphill or downhill slope?Given the above, no MSFS sims have any slope influence. That said, while I know several high fidelity airliner simulations allow you to enter the slope degrees in the MFC for takeoff thrust calculations, I highly doubt they are "interactive" and will have a bearing on your airplane performance. >4/. While I think of it, how about the differences>experienced between wet and dry runways?I have skidded a bit more on wet runways vs. dry, but other than that I can't speak to differences. Enjoy,-Greg

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I thought some payware scenery have sloped runways? Of course they aren't the standard runway texture but they are just the underneath texture. (I think if the scenery is based on round-earth or something like that)Here's the scenery I'm thinking of:http://www.llhinfo.com/lflj_en.html

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Aerosoft's Lukla has a sloped runway as well. I don't think the slope has any effect on the aircraft though.

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I made a sloped runway once in FSX. It worked great for the user aircraft, but AI would not use it. I think that is the main reason why we don't see more of them. It seems to me to be most suited for small GA fields where no AI are needed.RhettFS box: E8500 (@ 3.80 ghz), AC Freezer 7 Pro, ASUS P5E3 Premium, BFG 8800GTX 756 (nVidia 169 WHQL), 4gb DDR3 1600 Patriot Cas7 7-7-7-20 (2T), PC Power 750, WD 150gb 10000rpm Raptor, Seagate 500gb, Silverstone TJ09 case, Vista Ultimate 64ASX Client: AMD 3700+ (@ 2.6 ghz), 7800GT

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>3/. To what extent (if any) does FSX - or any of the more>advanced airliner add-ons available - model the difference in>take-off performance for an uphill or downhill slope?You could quickly experiment on your own to find the answer.Take some small aircraft like C172 and perform some take-offs from roads or desert areas where terrain is visibly sloped. See if you notice any difference. If terrain is really sloped and the physics is done right you shouldn't even be able to taxi up the hill. I know I had done it before but I forgot what the conclusion was.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

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>>You could quickly experiment on your own to find the answer.>>Take some small aircraft like C172 and perform some take-offs>from roads or desert areas where terrain is visibly sloped.>See if you notice any difference. If terrain is really sloped>and the physics is done right you shouldn't even be able to>taxi up the hill. I know I had done it before but I forgot>what the conclusion was.>Those hills, outside airport boundaries do work. I've often rolled down hills in GA aircraft to build airspeed and glide away.....just like a video circulating on You Tube recently. Going uphill, the aircraft will decelerate, as it should.L.Adamson

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Thanks to all for their replies. I like the one about attempting to taxi/take-off on hills outside the airports to see if the physices is modelled. The question is: why CAN'T we have sloping runways at airports? Seeing as they exist in the real world.... At least if it looked as though it sloped regardless of whether or not it made a difference that would be a start. For correct ops with airliners, slopes + wet/dry surfaces do make a difference. At the airport I mentioned for example the uphill r/w is very definitely limiting when approaching maximum weights for the a/c that use it.To expand my original post a bit: If FSX does not give these advanced features for us hard-core types, what DOES it give over an FS9 with all the add-ons (scenery, meshes etc) when considering airliner simulation? (Let's ignore "eye candy" and fancy views for now....) Better pressurization model for example? Runway friction coefficient?? Etc.Any thoughts anyone? AndyPS I'm throwing the gauntlet down here. Come on guys, persuade me!!

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>Aerosoft's Lukla has a sloped runway as well. I don't think>the slope has any effect on the aircraft though.Don't stop on the runway without your parking brake set then! :-lol Even with the parking brake, some a/c will still roll downhill 'cause their brakes are weak... *:-* As to the OP's question "why not," that's pretty simple to answer. ACES simply ran out of time to fully convert all the necessary code to allow for airport runways, taxiways, and aprons to work with the completely new, "round earth" paradigm.

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@Andy:What if you threw down a gauntlet, and nobody was there for you to fight with? That looks to me kind of what you are doing.Firstly, I would suggest that most of the improvements of FSX over FS9 are "fancy views and eye candy", things including improved textures, lighting, a large increase in the number of visible polygons, and a vastly improved terrain mesh out of the box. The trouble is that sometimes the eye candy has very practical values, and sometimes it's just really pretty. I can't fathom where you stand on the subject, so it seems to me pointless to lecture to you on it. "Eye candy" comes with a price in frame rates, too. Without knowing how you prioritize having pretty scenery versus smooth frame rates, there's also very little I think we can usefully discuss.FSX seems to be geared towards low-level GA flights and adventure flights that don't use up a lot of scenery (in the Missions). In fact in terms of pure content, I would suggest that it's the Missions that make FSX really stand out over FS9.But if you don't want missions, and all you want to do is fly airlines, then FS9 is probably better. There have been some good airline add-ons recently for FSX, but I don't have any of them, so I can't compare them to say the PMDG 737NG. Maybe if you are into virtual air traffic control, such as VATSIM and others, FSX is better, but I know very little on that score. Then there's X-Plane: maybe that's more to your liking.What I can definitely tell you is that there is no law or rule against owning and using more than one flight sim. If you prefer one over the other, then by all means go for it. I think that FSX, FS9, and X-Plane each represent great value for the money, if you are an avid sim-pilot. Each has its own strengths and weaknesses, none will break your budget (at least until you get hooked into add-ons and peripherals...)Jeff ShylukAssistant Managing EditorSenior Staff ReviewerAVSIM

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>To expand my original post a bit: If FSX does not give these>advanced features for us hard-core types, what DOES it give>over an FS9 with all the add-ons (scenery, meshes etc) when>considering airliner simulation? (Let's ignore "eye candy">and fancy views for now....) Better pressurization model for>example? Runway friction coefficient?? Etc.>>Any thoughts anyone? >>Andy>>PS I'm throwing the gauntlet down here. Come on guys,>persuade me!! Runway friction coefficiency? Please don't take my comments to be anything more than what they are, but unless you have your ATPL or an advanced degree in physics, how in the world are you going to know if any of your desired features, for the "hard-core types", are accurate or not?

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>>As to the OP's question "why not," that's pretty simple to>answer. ACES simply ran out of time to fully convert all the>necessary code to allow for airport runways, taxiways, and>aprons to work with the completely new, "round earth">paradigm.I was thinking about this, and almost responded yesterday, but didn't. I can't resist responding Bill, with my thoughts on it:If this can be implemented for FS11, it would imo be a great step forward. If it cannot be implemented in FS11, it won't break my heart.That's all I wanted to say on it :D (I like to think about the future of the sim)RhettFS box: E8500 (@ 3.80 ghz), AC Freezer 7 Pro, ASUS P5E3 Premium, BFG 8800GTX 756 (nVidia 169 WHQL), 4gb DDR3 1600 Patriot Cas7 7-7-7-20 (2T), PC Power 750, WD 150gb 10000rpm Raptor, Seagate 500gb, Silverstone TJ09 case, Vista Ultimate 64ASX Client: AMD 3700+ (@ 2.6 ghz), 7800GT

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>>As to the OP's question "why not," that's pretty simple to>>answer. ACES simply ran out of time to fully convert all the>>necessary code to allow for airport runways, taxiways, and>>aprons to work with the completely new, "round earth">>paradigm.>>I was thinking about this, and almost responded yesterday, but>didn't. I can't resist responding Bill, with my thoughts on>it:>>If this can be implemented for FS11, it would imo be a great>step forward. If it cannot be implemented in FS11, it won't>break my heart.>>That's all I wanted to say on it :D (I like to think about>the future of the sim)Well, it's obviously far too early to form any type of conclusions yet, but consider the following known facts carefully:1. Train Sim 2 is being programmed to use the same core platform that will also be the foundation for FSvNext.2. Everything in TS2 is anchored to the ground, so obviously will have to conform to the "round earth paradigm" precisely.3. TS2 will be released at least a full year before FSvNext.It would therefore seem reasonable to hypothesize then that this same solution will be useful for ground objects such as airports in FSvNext. :)

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