"I wish there was a really good add-on that would show a good simulation of heavy rain, skud, low clouds and gusty winds.
The weather simulation of clouds and rain in FSX is pretty poor."

Lou, I dont know if you have tried it yet, but there is a free (at least for now) program that does a pretty good job with winds, clouds, etc....

I have Active Sky too but this one is pretty impressive...FXrealWX


http://www.rs-transline.de/index.php?page=self&id=2#

It's stand alone. As far as features, install it and take a look, it's free.

http://img17.imageshack.us/img17/6619/microburstnasa.jpg


The above drawing shows a good view of what the down burst looks like. The down burst is caused by the collapse of the updraft part of the cell. The storm can no longer keep the column of air rising and as the air begins to fall the rain cooling speeds the descent of the air mass. Down bursts are generally of short duration, but super cells can produce fairly large down bursts of several minutes. As you see in the drawing the column hits the ground and spreads out in all directions. If the down burst is right over the approach end of the runway this spells the worst for the approaching plane. As the plane flies inbound on the ILS, the pilot firsts sees an increase in airspeed with a ballooning upward. The pilot adjusts pitch to control the climb and pulls back on the thrust. As the plane nears the approach end of the runway it enters the area of the shear with the vertical component. The aircraft now begins a rapid sink rate and looses the head wind. If the pilot makes it past that, he encounters the loss shear part of the down burst and unless the plane can power out of the shear it will impact the ground.

Delta 191, a Lockheed L-1011 had just such a down burst landing in KDAL several decades ago. Eastern Airlines also lost a 727 landing KJFK runway 22L during a similar event.

Thunderstorms in the eastern part of the U.S. generally have low ceilings and poor visibility, whereas storms in the west have high base cells with more visibility. Don't confuse Virga with a down burst. Virga is a form of precipitation that evaporates before it hits the ground. Low humidity and high temperatures can cause rain to evaporate completely shortly after its release from a cloud. Desert areas often have clouds showing virga. In fact, the precipitation often starts out in the form of ice crystals and never reaches the ground.

Lou, using FSreal I have made quite a few approaches when the RW weather was under 200 and 1/4 and I couldnt see the runway until I was almost on it. You milage may vary but on my system it's pretty accurate.

darn Lou! Now I need to go get the 172 out! Only problem is, I'm in S Florida and theres nothing to look at, let alone like you pic. Reminds me of flying in the NE, I got my ticket in Maine, we know scud! 

You are right, there is nothing for FSX that will ever look that good, darn it, but tks for the pic.

Nice picture indeed and thanks for the explanation, Lou.
How can pilots train to get aware and act timely and correct when approaching such conditions like the microburst?

You've pointed out the first signs, like the increase in speed and lift, is that the last stage where the people in the cockpit can actually do something to influence their fate?
Talking about seconds there, so no big room for discussing further measures. Will the windshear warning and weather radar help them?


And Jay's tip about that other weather program is indeed a nice one. That thing does nice weather so far, similar to my fancy and expensive payware while of course still lacking features to enable a "real weather" in FSX.
But that may well be limited by the FSX weather engine itself, not by the programs, already trying to work around some limitations there.
I've donated over at their site, because the current version really does what it should while not eating any huge resources.

Lou

Delta's policy on this type of situation prior to the crash was to stablize the plane and continue the approach and landing. After the crash and investigation the policy was to stablize the plane and get out of there. Try another runway or alternate or wait for the storm to pass. I believe that as part of the NTSB investigation there were about 10 flighdeck crews in simulators that were unaware of what conditions they about to fly into. All of them lost control and crashed.

Michael Cubine

CoolP, as Michael said many of the pilots of that day were unaware of the danger posed by these down burst events. The NWS made great strides during the 60's and 70's trying to understand the danger of these powerful shears. A lot was learned and studied about thunderstorms and windshear and today with computers and training, flying is much safer.

Aviation is safer because we try to learn from mistakes.

Lou