Page 4 of 4

Re: Naturally Aspirated GA Airplanes -- High or Low?

Posted: 31 Dec 2018, 06:42
by Hook
I just remembered what that published ice gauge did. Anyone who thinks FSX ice is wrong should install that gauge.

Re: Naturally Aspirated GA Airplanes -- High or Low?

Posted: 31 Dec 2018, 12:32
by AKar
Well, I ought not need a gauge if it worked good enough. Having it there to punch a sledgehammer against my face if I fly in freezing rain is all but useless to me as I don't intent to take my airplane into some any more than I am intending to take one into a developed CB cloud. It is not my priority. Instead, for a proper simulation, I'd like to have proper accumulation rates in appropriate conditions with their corresponding effects in conditions that would not be grossly outside the expected operational conditions of the airplanes we commonly simulate. To have a hazard that often can be dealt with lurking in appropriate conditions. And hey - no overdoing! I like none of that make an area size of Belgium unflyable if a METAR reports thunderstorms in vicinity bullshit! :mrgreen:

But I guess that's enough about FSX/P3D icing without a dedicated thread from my part. :)

I need to check that place, Mena, AR. Unknown to me but sounds fun!

Happy 2019 everyone! :)

-Esa

Re: Naturally Aspirated GA Airplanes -- High or Low?

Posted: 31 Dec 2018, 12:43
by ClipperLuna
AKar wrote:Thanks, at least summer representation of the scenery looks very decent in the sim. What I absolutely love to do when I've got some good time to allocate into a flight sim session is to take the flight in the sim, record it, and then review it in Google Earth, checking any Street Views or 360° images while finding out about interesting places. :)

-Esa
Definitely! I'll never forget the first time I (virtually) flew over Butte Montana and saw the Berkeley pit just north of town. I thought it was a software glitch at the time, then come to find out there really is a big deep pit there :o . It felt nice knowing all about it when I actually traveled to Butte.

Re: Naturally Aspirated GA Airplanes -- High or Low?

Posted: 31 Dec 2018, 16:34
by Hook
Sorry Akar. :)

What that gauge does it at some point during icing it will lock your controls at an extreme setting causing you to crash with no way to recover or avoid it. Basically, it creates an unavoidable random instant death scenario. The icing doesn't have to be extreme for this to happen. You can guess what that makes flying like when the weather is cold. The actual ice indicator is three lights, green-yellow-red. I don't remember what else it might have done. This is not something I'd like to see in stock FSX and I doubt I'm alone.

If it increased your stall speed and added stall buffet as a warning, this would be good.

I think that mountain range is called Iron Mountain. It runs between the PGO VOR and KMEZ. Doing that flight in real life is on my bucket list.

Hook

Re: Naturally Aspirated GA Airplanes -- High or Low?

Posted: 31 Dec 2018, 16:45
by AKar
Hook wrote:Sorry Akar. :)
Not sure if joking, but I never tried it, nor I found the gauge you perhaps were referring into. :) My comments were on earlier FSX/P3D experiences solely.

-Esa

Re: Naturally Aspirated GA Airplanes -- High or Low?

Posted: 31 Dec 2018, 17:33
by Hook
Google "ice gauge FSX" and you will find links. There are two versions in the Avsim library, one updated from the other. It is called iceV10. The documentation has a lot of information on icing in FSX and FS9 and is worth a read.

Hook

Re: Naturally Aspirated GA Airplanes -- High or Low?

Posted: 01 Jan 2019, 07:26
by Hook
Update: The documentation is useful, the gauge might not be. The code has bugs that will reduce or eliminate the effects he is trying to produce. Try flying slow or lowering your flaps when the gauge is yellow for moderate ice. Red for severe doesn't appear to do anything.

Re: Naturally Aspirated GA Airplanes -- High or Low?

Posted: 04 Jan 2019, 21:40
by Hook
I am narrowing in on how to predict icing.

Freezing rain will produce moderate to severe ice accumulation.

Snow does not cause ice but can be mixed with freezing rain which can. There is usually no indication that the snow includes freezing rain.

Clouds will cause light to moderate ice accumulation if you fly in or near them and the temperature is between 0 and about -10 C. I am currently guessing at the -10 as I did not get ice at -14 C or lower. The most common problem flying near clouds is flying just above or just below an overcast layer. Generally the icing is mild and you aren't in a cloud long enough for it to be a problem as it will dissipate slowly when you are out of the clouds.

I added a display of the variable used by the sim to determine when you are in clouds, and the variable will show in clouds when you are near them and not just when you are actually in the depicted cloud. This will also account for some cloud turbulence when you are near a depicted cloud but not inside it.

The actual weight gain from ice is negligible: in my 3800 pound aircraft 9% ice caused a weight gain of 9 pounds after accounting for fuel burned during the time ice was accumulating. You still lose airspeed and altitude and end up in a nose up attitude, but I'm not sure how much of this is changes to lift or drag and how much is caused by prop icing. I have seen no evidence yet that stall speed is increased, but this may be moot as the angle of attack may be exaggerated.

Icing can go above 100% so it's not strictly a percentage. You might even still be flying at the time. :)

Like the statement I made that started this whole discussion: this time of year you fly at whatever altitude you need to in order to avoid icing. In clear weather you can fly whatever altitude you wish. With clouds, especially when icing is possible, you may not be able to fly the altitude or even the course you want.

Hook

Re: Naturally Aspirated GA Airplanes -- High or Low?

Posted: 11 Jan 2019, 03:07
by Hook
I have completed my flight in the far north and have moved to the tropics. I won't see any more ice for a while.

At one point I thought I had a complete handle on when to expect cloud ice. I was not getting any ice indication at -9 C, but was getting it at -8 or a bit above. Only one problem. I flew for several hours in temperatures that ranged from -9 C to -5 C, obviously in clouds with the cloud indicator turned on, but I only experienced icing for a few seconds at a time, twice. There are obviously other parameters involved. Humidity (or the separation between temperature and dew point on the ground)? I don't know. Is there anything else that might account for not getting cloud ice when expecting it (real world, that is)? It may be that you only get ice in certain types of clouds. The only thing I can say for relative certainty is that I never experienced cloud ice when the temperature was -20 C or below.

Since I was watching closely for it, I did notice that even 1% made a difference in the aircraft. Some of this was due to carb icing.

The actual variable that determines the speed of ice accumulation is not available, but it can be turned on, even when not in clouds, by the weather program in use. The problem here may be Active Sky, not FSX. The next time I expect to be flying in ice I will have the aircraft set up with prop deice that comes on when you turn on carb heat with the H key (but not when you click on the lever in the cockpit). That way I can determine exactly how much of the performance degradation is due to structural ice and with carb heat turned on all the time the performance won't be affected because I'll already be accounting for it..

Hook

Re: Naturally Aspirated GA Airplanes -- High or Low?

Posted: 08 May 2019, 17:56
by Hook
I discovered another altitude limit. When flying in the vicinity of thunderstorms you want to stay high enough to recover from a turbulence or wind shear induced stall, but low enough to stay out of the clouds, where the turbulence will be very bad indeed.

I've flown through thunderstorms many times without problems, but always below the cloud ceiling. There will be rain, and lightning all around, but it's really no worse than flying in rain.

Twice I've gotten into trouble.

The first time was some weeks ago when the cloud ceiling dropped to ground level and I tried to fly through the clouds in thunderstorm conditions without realizing that the extreme cloud turbulence would extend all the way to the ground. I left the plane on the ground after the inevitable crash, exited the sim, then reloaded it with better weather to continue the flight.

The second time was the flight I just landed from. The weather map showed some thunderstorms but it didn't look too bad until I was actually in the sim where the map was pretty much covered in red. I had figured I'd fly out of the weather after about 15 minutes but hadn't counted on the area increasing in size during the flight and it actually took a half hour. While I had some turbulence and wind shear as soon as I took off and turned crosswind leg it wasn't bad enough to make me complete the pattern and land.

Soon enough the weather map showed a nearby wind shear, and indicated I was flying in severe turbulence in heavy rain. Still, nothing I hadn't encountered before. Then I got a nasty wind shear with a stall and spin and I bounced off the ground.

I continued the flight with frequent wind shear bad enough to stall the plane, but I figured out how to handle it. This was good practice as I wasn't used to a stall coming on for no apparent reason and wasn't getting into stall recovery mental mode. After experiencing several of these and learning to deal with them it wasn't too bad, at least for flying in a sim. Two problems here were the nearby wind shear and getting into the base of the cloud effect just below the actual ceiling, and I couldn't determine exactly where it was. I just flew lower when I realized what was happening.

Moderate and severe turbulence would be a lot more difficult in A2A planes. I was flying the Golden Age Super Stearman.

Hook

Re: Naturally Aspirated GA Airplanes -- High or Low?

Posted: 08 May 2019, 20:41
by n421nj
Depending on winds of course but higher the better