Is OpusFSX currently generating localised mechanical turbulence? The reason I ask is I have noticed I some very strong low level windshear occasionally flying into some airports that have terrain or structures near the approach when the wind is coming from that direction. It is usually an overshot shear followed by a large undershoot shear. Or is this a function of FSX? It's sort of realistic but it seems a little strong when the wind speed is taken into account.

 

Matt

Yes, both as intelligently controlled turbulence effects, which factors in low level mechanical or rotor turbulence effects in addition to many other forms, and as additional site specific effects. The additional site effects have been present in the recent beta and release versions although unannounced. The latest beta posting has announced the official inclusion of additional site specific turbulence effects, the software for which has now completed its initial in-house development and alpha testing. The additional site effects can be configured to accommodate all manner of localised site turbulence and wind shear warnings. There is also provision for the user to specify their own site effects for their favourite airports or airfields, whether real or not. Please read our SimForums Announcements.

 

Stephen :-)

 

I should have pointed out that the low level turbulence calculations factor in much more than just wind speed, although strong and/or gusting wind conditions will result in added turbulence. Factors such as temperature, cloud layers, inversions, localised weather (the presence of CBs or TCUs etc.) will all contribute.

 

Stephen

 

Hi Matt

 

I should have also pointed out that the algorithm does err on the side of stronger rather than weaker turbulence, this was changed after users requested greater levels of turbulence. If you find the effects too severe for the conditions you could try ticking the Less Turbulence option in the relevant DHM dialogs. If it persists then I will take a general census and adjust the algorithm accordingly.

 

Stephen :-)

Ah ok that's great, having just read the announcement I see I can tweak the settings to my desired level. When I get home I'll have a look into the settings. It's pretty exciting stuff. I noticed at Sydney on 16R I got the severe shear effects of overshoot followed by undershoot with a wind direction of 090/12. In reality on this runway you only get light turbulence when the wind comes from the SW at around 15 knots increasing to moderate once the wind speed gets above around 25 knots other directions are fine. Will my settings remain in place if I reinstall a new version?

 

Thanks for the info Stephen.

The new site effects at present just add to the normal calculated turbulence effects. So I would advise setting the Lower Turbulence option and then adding your own effects. It is early days for this feature so please feel free to comment and make any suggestions either here or on SimForums. We have an opportunity with this new feature to be quite creative and put greater control over both added and calculated turbulence into the hands of the user and of course be very site specific.

 

I am sure it will provide a great new feature.

 

Stephen

Mat

 

This has already given me a few more ideas. I will look into splitting the algorithm that calculates low level turbulence into two parts. Those conditions that always cause added turbulence no matter what the site, such as very strong or gusting winds, proximity of CBs etc. and those conditions that may be considered site dependent but are just factored in as guess work. Then if a user or Opus specifies some site specific effects then these effects should replace the guess work in the LWE, leaving it up to the specified site conditions to determine ALL additional turbulence and wind shear at that site.

 

Stephen

Ok great, I'm really loving your software. If I can make an observation based on 19 years of airline flying I'd say the effects are a little too pronounced. If others are happy with the current level I'm happy to try turning the effects to low on my system. Am I right in assuming I'm only adjusting the threshold values. Ie I'll still get severe effects if the condition are extreme?

 

This is a great feature and has huge potential as even full blown commercial full flight simulators can't recreate these effects they only insert a canned type of turbulence that is non dynamic or pre programmed dynamic events. Good job!

Great idea Stephen, could having separate events allow different effects ie the overshot/undershoot is normally associated with cb's where the rock and roll followed by undershoot is normally associated with mechanical effects from structures etc. and terrain normally has undershoot followed by overshoot as you cross the terrain. Would be very cool!!!

I am already thinking about what can be done to give more control and flexibility to the site specific effects. I have announced changes to come in SimForums Coming Soon, recognising your input here Mat. I also preferred the previous level but received lots of requests to make things more pronounced. The Lower option is supposed to put things back to similar levels that used to be calculated although the algorithm has changed since then.

 

I have little control over wind shears which are specified but then must be left to FSX to simulate. But I do have full control over the strength of turbulence which the LWE can control in real time. So wind shears will be specified for the general area surrounding the airport whereas turbulence will be more specific and localised.

 

Stephen

Can you control the altitude band it occurs at? Eg mech turb off a structure would cause an effect (depending on wind speed) say 100-200 ft above the structure, however once you transition below the height of the structure you generally exit the mech turb. Unless of course you have rotor effects ( unlikely from structures however). It may actually do this at the moment?

I'll head over to simforums and have a read.

 

Matt

Undershoots and Overshoots ...

 

I did experiment and include an extra degree of turbulent change affecting the aircraft's height, trying to recreate some turbulent motions a little better. This was included without any announcement in a beta some time back, however, I immediately received a few complaints that their aircraft was being pushed down toward the ground on occasions. It is quite possible that I had overdone these effects for some users systems so I immediately disabled them. I may however experiment a bit further to see if they can be used with a little more finess to create undershoot and overshoot tendencies.

 

Stephen

 

Yes, at quite a fine resolution for turbulent effects, the max elevation specified in the actual site effects. But only to a lesser extent for FSX controlled wind shears.

 

At the moment we have graduated the added turbulence effects based on 15% and 30% boundaries. So if you specified severe turbulence within 3km (measured from the site's defined lat/lon so that normally implies an area extending out to about 1km beyond the runway threshold) below 1000 feet (AGL) then the LWE will give a slight increase when you descend below 1000' AGL, moderate turbulence below 850' AGL, and finally severe turbulence below 700' AGL. The graduated effects applies to all limits specified for the site effect.

 

You can use the Runway, Direction, or Bearing parameters to add further limits to the effect and in that way limit the effects to a certain approach.

 

Stephen

 

You can test any of your specified effects using a GLOB imported METAR to specify the weather, using Slew mode to raise the aircraft off the ground and position it on the approach, or simulate an approach. It is best with FSX in windowed mode so you can have the Spy window open at the time, the LWE displays the results of all site related turbulence changes in the window, identifying which site effect factored in the most. For example,

 

Site Effect 4: Turbulence Increase 2

 

Of course this is the first beta so I expect there will be a steady stream of improvements and enhancements. Should be interesting.

 

Stephen

Yes I remember that beta I nearly splashed my NGX going into YBHM as the undershoot was so severe. At the time I was unaware it was opus generating it, I only clued up doing an approach last week. Very slight effects with the same motion overshoot then undershoot would be very realistic as these almost always accompany the shake of mech turb. The effect would generally cause no more than a slight change to aiming point unless the conditions were extreme, from a cockpit perspective vertical speed change would be in the order of 100 ft/m each way. We can continue this at Simforums if you like, I'm logged in there now and have a lot of reading to do to catch up

 

Matt

I think I definitely overdid the effects in that beta, they look reasonable on my system but that was with a Lancair Legacy. They have promise though as I could use them (toned down of course) with some small bias added within an undershoot or overshoot zone.

 

Probably best on continued SimForums. We will create a new Additional Site Effects, give us a few moments to prepare the topic and move some posts across.

 

Stephen