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The terror of the white room
Posted: Fri Oct 06, 2017 2:56 pm
Can someone please explain this?
Posted: Thu Oct 11, 2018 12:50 pm
It's a scary video. But can someone please help me (and probably others) understand what happened?
I understand "cloud suck" can eat up a glider into a cloud, and then if unable to descend fast enough or fly away from the cloud, then hypothermia may set in because it's literally freezing at the top of a cloud.
But, this video shows an airplane going out of control, faster and faster, down into the ground! For us, at Sylmar, does "ground" mean the top of the mountain (launch)? If so, then it makes sense to me, but seems unlikely. Can a cloud really grow so far down to end at or near the top of the mountain? I assumed clouds usually stay a distance above the mountain tops around here. I guess this means if the cloud starts to rain, then the fog may descend all the way to very near the ground?
I do not mean that I think the video is dumb or irrelevant, but honestly just want to know what it means.
Posted: Thu Oct 11, 2018 1:55 pm
A couple of things:
Cloud base often drops. I've seen it drop hundreds of feet at Kagel. I once launched with cloud base (very light suck) 50 feet over launch. 20 minutes later, it was 100 feet over Trash. Still very light suck. If the suck had been stronger....
Also, it is incredibly easy to lose your ability to judge what constitutes level flight when you have no visual reference. It is even easier to lose track of what direction you are going. Think of ending up behind launch in a 30 degree bank, pointed away from the mountain. And not enough altitude to get back to the front. And that's without worrying about cloud base dropping. If it dropped, you could exit the cloud pointed down and at the hill with mere feet to do something about it.
There is a reason that "regular" airplane pilots must take special courses to have instrument ratings. And they have to learn to ignore their own feelings and trust the instruments. Sort of the opposite of Star Wars.
The above is not including thunderstorm-strong cloud suck. That's a whole different kettle of mist. Lightning, Broken gliders, lack of oxygen, freezing cold, hail, downdrafts stronger than any wind you'd ever want to fly in.
I love getting to cloud base. I hate getting there near anything solid. I hate getting there in strong suck.
By the way, it is also illegal to fly through the cloud. Instrument rated pilots (like commercial jets) fly there. And you can't see them, nor they you.
Posted: Thu Oct 11, 2018 2:01 pm
Very interesting. Thanks! I was getting the same impression from the Youtube comments ~ cloudbase can drop suddenly. Actually I have experienced that before when hiking in mountains.
Does anybody fly with a bubble-level instrument, to detect which way is up in a situation like this? LOL
Posted: Thu Oct 11, 2018 2:07 pm
I added to the post after you posted. You were fast!
RE: bubble levels. I am told that they react too quickly, and jump all over the place. Maybe one could be built with very thick fluid, but a normal one is unlikely to help much. It really is very difficult to stay even close to level. Much more so than one would think. And if you enter the cloud non-level, it's ten times worse.
Posted: Thu Oct 11, 2018 5:29 pm
A bubble level won't tell you which way is up when it's in an airplane or a glider. For that you need a gyro or an IMU (inertial measurement unit).