Sylmar Hang Gliding Association Forum Index Sylmar Hang Gliding Association
Get High...Go Far...Tell Us About It
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

The terror of the white room

 
Post new topic   Reply to topic    Sylmar Hang Gliding Association Forum Index -> Non-Flying related
View previous topic :: View next topic  
Author Message
jfriesne



Joined: 21 Oct 2014
Posts: 29
Location: Pasadena, CA

PostPosted: Fri Oct 06, 2017 2:56 pm    Post subject: The terror of the white room Reply with quote Add User to Ignore List


Link
Back to top
View user's profile Send private message Visit poster's website
that.guy



Joined: 23 Aug 2018
Posts: 5
Location: Glendale, CA

PostPosted: Thu Oct 11, 2018 12:50 pm    Post subject: Can someone please explain this? Reply with quote Add User to Ignore List

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.
_________________
H3, 100 hrs, blue Sport 2 ... yea, I'm that cemetery landing guy. Don't worry, I've gotten a bit older and wiser since. Need more cloudbase for the video compilation!
Back to top
View user's profile Send private message
stebbins



Joined: 24 Feb 2005
Posts: 606
Location: Palmdale, CA

PostPosted: Thu Oct 11, 2018 1:55 pm    Post subject: Reply with quote Add User to Ignore List

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.
_________________
Fly High; Fly Far; Fly Safe -- George


Last edited by stebbins on Thu Oct 11, 2018 2:03 pm; edited 1 time in total
Back to top
View user's profile Send private message
that.guy



Joined: 23 Aug 2018
Posts: 5
Location: Glendale, CA

PostPosted: Thu Oct 11, 2018 2:01 pm    Post subject: Reply with quote Add User to Ignore List

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
_________________
H3, 100 hrs, blue Sport 2 ... yea, I'm that cemetery landing guy. Don't worry, I've gotten a bit older and wiser since. Need more cloudbase for the video compilation!
Back to top
View user's profile Send private message
stebbins



Joined: 24 Feb 2005
Posts: 606
Location: Palmdale, CA

PostPosted: Thu Oct 11, 2018 2:07 pm    Post subject: Reply with quote Add User to Ignore List

I added to the post after you posted. You were fast! Wink

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.
_________________
Fly High; Fly Far; Fly Safe -- George
Back to top
View user's profile Send private message
Greg Kendall



Joined: 24 Dec 2006
Posts: 43

PostPosted: Thu Oct 11, 2018 5:29 pm    Post subject: Reply with quote Add User to Ignore List

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).
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Sylmar Hang Gliding Association Forum Index -> Non-Flying related All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group