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Guest davidvoogd

Thermal issue

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First of all I must say I love the thermals! They add so much more realism especially flying general aviation aircraft! One badly located thermal can really upset your approach, just as happens in real life (where I did my flight training the one approach had a gravel pit - then a river - then a forest - then a road - then grass ... you were up and down like a yoyo on a sunny day lol!)However I ran into one issue today - flying into Toronto there was a massive thermal right above runway 24R - it was so strong I actually was unable to land - it held my Cessna 182RG right up in the air even at idle power lol!I know from real world experience in 172's a good thermal can prevent you from decending and will hold you up, but I've never experienced that close to the ground. Is this realistic that close to the ground (under 100 feet)? I'm not sure if this is an issue or not - just a unique situation for sure! I tried a couple of times to land - eventually I got it down on the far end of the runway where the thermal died down a bit.

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>First of all I must say I love the thermals! They add so much>more realism especially flying general aviation aircraft! One>badly located thermal can really upset your approach, just as>happens in real life (where I did my flight training the one>approach had a gravel pit - then a river - then a forest ->then a road - then grass ... you were up and down like a yoyo>on a sunny day lol!)>>However I ran into one issue today - flying into Toronto there>was a massive thermal right above runway 24R - it was so>strong I actually was unable to land - it held my Cessna 182RG>right up in the air even at idle power lol!>>I know from real world experience in 172's a good thermal can>prevent you from decending and will hold you up, but I've>never experienced that close to the ground. Is this realistic>that close to the ground (under 100 feet)? >>I'm not sure if this is an issue or not - just a unique>situation for sure! I tried a couple of times to land ->eventually I got it down on the far end of the runway where>the thermal died down a bit.>>Very realistic, ask any airline pilot trying to land at Sky Harbor in Phoenix.

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Hi,The VAS auto generation should not create a thermal so low to the ground... either there was a manual thermal created at that location (highly possible as Jim mentioned a tester or two did this by accident). You can check your thermals.txt file to see if there is an entry there... Deleting the entry (or the file) would thus get rid of the problem. Does this help?

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I have not created any custom thermals, I don't have a thermals.txt file anywhere in the ASV folders either. Here is a pic of one of my attempts - in this picture the aircraft is not decending - but flying level with the engine idle. This is at CYYZ - runway 24R around 9:17am local (Eastern) time yesterday. My altitude here is 621 feet - the airport elevation is 569 feet so this was only at 52 feet above the ground.http://ca.geocities.com/davidvoogd@rogers.com/thermal.jpg

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No problem, I haven't experienced it again yet, I'll let you know if I do.

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If I might also jump in here. I've experienced a similar situation with ASV, landing at Swansea,UK in the F1 PC-12. I was caught by a strong updraft as I flared over the runway threshold and ended up landing nosewheel first, bouncing 200 meters and finally touching down, throttle idle, at 47 KIAS halfway down the runway. Most embarrasing. It seemed to me that the thermal was acting on the aircraft at a much too low AGL. I'm sure it wasn't wake turbulence as no AI planes had landed ahead of me and I run ASV over WideFS and the event was displayed as a VAS.I was also wondering if the onset of the thermals was a little too abrupt. Flying the RealAir SF260, as I encounter a thermal there's quite a strong bounce caused by the head latency feature. Though I'm not a real world pilot, I would have thought that encountering a thermal would not be so sudden. I guess that I'm wondering if it might be useful to have a feature which controls the speed of onset of the thermal and another feature which controls the height AGL at which it begins.Other than that I'm most pleased with ASV.David S.

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From my limited real flying in 172's - from what I recall when you get into a strong thermal it feels like a swift kick in the rear and up you go - it can be rather abrupt. In that aspect I've found them to be very realistic.

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Hi,I had the same problem with ASV and the Cessna 182RG by Carenado yesterday. I had 20 degrees pitch down attitude, flew only 60 knots, idle power and did not lose any altitude. I had the feeling that the flight model was somehow damaged.Regards,Henri

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Incredibly I had a similar problem but with the Level-D 767. I was landing at Madeira (LPMA) last night at runway 23, full flaps, gear down, flying visually from FUN VOR to the TZE and the aircraft simply did not descend normally. I did retard the throtlles to idle still no sinking at all so I pitched down. Of course I descended but my IAS rapidly increased and I landed in the midle of the runway, having to backtrack to vacate. So the VAS system appears to be quite realistic for the GA while in cruise. But for a heavie in final approach on an island I think it is too much realistic, so that you could not land. I will try again in another flight with the same aircraft. If I experience continuous updrafts spoiling my approach, I'm affraid I will deactivate the VAS system.Best regards,

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Oh yes, that is a problem. I just tried to land a 182 at Short field landing speed, which is 60 knots. The plane should be smacking the runway. Instead, I drifted the entire length of a 8,000 ft runway, with full flaps, power pulled, and could not descend below 100-200 ft above the runway. Never had it before AVS. VAS was set at 40%. There is definately something wrong. It happened to me yesterday in a Warrior as well. CB

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