Mike Ash wrote:
In article
,
a wrote:

So help a non-glider pilot here. I take it the lennies simply mark the
altitude where the RH goes to 100% but the updraft continues well
above that?

Right. The structure of the wave is a wavelength a couple of miles long,
and an amplitude of, I'm not even sure, a couple thousand feet? There's
sometimes a certain altitude where the RH is near enough to 100% that
the lifting part of the wave is enough to cause the moisture to condense
out and form a cloud, but that's not a requirement for lift. You can
generally find lift above and below the lennies, as well as in places
where the wind and temperature profile is correct for wave but the RH is
never high enough for cloud formation.

It looks like the distance between the lines is not that
great, so I expect it would be a bumpy ride for us guys who buy lift
by the gallon if we were flyong toward the mountain.

Actually, that's the great thing about wave: the air is absolutely
perfectly 100% smooth. There were many times today where both of us had
our hands off the controls and the glider would just keep on doing its
thing with no real disturbances. A power pilot might notice the
transitions from up to down if he's watching his rate of climb
indicator, or seeing that he's making periodic alterations to maintain
altitude, but the transition from up to down is completely smooth and
there's no turbulence.

Underneath the wave, below the laminar layer, you get a turbulent layer
of rotor which can be incredibly violent, like frequent negative gees
causing various loose items to get all floaty in the cockpit violent.
The really fun thing about wave flying in a glider is that you often get
to TOW through that region, so you're experiencing this crazy turbulence
while tied to another airplane with 200ft of rope. It gets exciting, to
say the least. Today was pretty mild, just took some work to stay in
roughly the right position.

Maybe the no
'marker clouds' you mentioned may simply mean the air lost its
moisture on the up windward side of the mountain, there was nothing
left to condense out. The 'initial gust' from a thunderstorm is often
pretty dry, it left its water up there to turn into hail and a
downpour.

Yes, that certainly could be (it's common for there to be a solid cloud
deck on the upwind side of the mountains on these days, and broken
lennies downwind) or it could simply be that the air in that location
doesn't have enough moisture in the first place. Or, the third
possibility is that there's just no more wave over there. I was trying
to figure out whether it was no wave or just no moisture today, and from
what we found it seemed that it might have been a mixture of both.

Hypothetical question, because you of course would never do this, but
how often do sailplane pilots mess around closer to the clouds than
someone who treated the FARs as something never to be violated?

Yes, of course we would never do this....

One incident that I will talk about freely because it was an honest
emergency was about a week ago when I was trying to connect with wave,
and I did, in a cloudy patch. As I was climbing up through the clouds I
discovered that they were growing in that area, and soon found myself
cut off from being able to fly in any location free of the clouds.
(Imagine the classic box canyon scenario, but with soft fluffy clouds
instead of hard rock.) Once I realized the situation I immediately
pulled the spoilers and initiated a steep spiral descent through a milky
hole below me. I wasn't in serious danger because I only had to lose
about 1000ft to get under them, and I couldn't have exceeded my redline
or gee limits before breaking into clear air again, but it was nearly an
accidental VFR-into-IMC and definitely violated the cloud clearance regs
when the stuff started to grow all of a sudden.

Hypothetically speaking, a glider pilot on a good thermal day might ride
the thermal up to cloud base, and call whatever distance he can see
between him and the cloud "500ft", since it's very difficult to judge
the exact distance.

Great set of photos, but the panel isn't showing tach, fuel gauge, nav
1 and 2, comm 1 and 2, AH, etc etc. Waddaya doing, flying by outside
reference?

I noted with some amusement at one point in the flight that the most
powerful navigational instrument in the plane, by a huge margin, was my
phone. Other than that, all we had was a compass and a pair of sectional
charts. Of course, with unlimited visibility and a horizon distance of
over 100 miles, it would have been incredibly difficult to get lost.

I also did not notice the traditional piece of yarn taped to the
windscreen.

You can see a bit of it here, at the top:

http://pix.mikeash.com/v/wave1109/IMG_0227.JPG.html

There is also one taped to the front canopy, but it is blocked by my
brother's head, which of course is why the back-seater gets his own.
Flying from the back is interesting at times. For example, with a
reasonably tall passenger in the front seat, the ideal position while on
tow is when the tow plane's wings are coming out of the passenger's ears.

Nice post.

Thank you! I hope it might serve as an inspiration to others as well.
I'm happy to talk about gliders all day long, but I'm here to read some
interesting stuff about how the "other side" lives too.


I had a boss that was an accomplished glider pilot, but never had the
chance to get a ride. Something I want to do. I did do a balloon ride
and that was fun. I got to "fly" the balloon when the pilot learned that
I was a fixed wing pilot. Boy are they slow to respond to commands.
About 20 to 30 seconds after hitting the burner.

--

Regards, Ross
C-172F 180HP
Sold
KSWI