High flight

Forgive the crosspost, but as both groups are low on relevant content at
the moment I thought it might be good to give both of them a boost.

My brother is in town this week for the holidays. He's with his
grandmother some distance away, but the gliderport is between us. He's
taken glider lessons up to solo and I thought that getting together to
fly would be a fun activity.

As chance would have it, the forecast for today was calling for wave. My
brother has done a lot of training, with tons of pattern tows, but very
little actual soaring. I figured that a nice wave flight would really
show him a totally new aspect to the sport.

Driving out to the airport, there were lennies stretching across the
sky, one after the other. Once there, I got everything ready as quickly
as I could. My brother showed up on time and we launched at about 10AM
in the club's Grob 103, hoping to catch the wave before it dissipated.

We towed through some fairly mild but still challenging rotor, then hit
a patch of what looked like wave lift at about 2,000ft above the
airport. Too chicken to try for it, I kept on tow looking to make it to
the next harmonic and a little higher before releasing. We spent what
seemed like a terribly long time barely climbing at all while on tow,
which I took to be a good sign (if air is going down, it must be going
up somewhere else!) and finally pegged the variometer coming out the
other side. Released into slightly chunky wave at 3,300ft above the
airport (4,000MSL) but soon established a solid climb.

The next three hours were some of the most pure fun and enjoyment you
can have. We had a solid climb up to about 9,000MSL averaging probably
3-4kts climb, and I introduced my brother to the basic ideas of wave and
how it all works. The lennies were scarce near the airport but more
solid to the north (northwesterly wind, so the wave bars were running
northeast/southwest) and we headed up that way.

After topping out the climb I got to teach my brother how to jump
forward to the next harmonic. Cranked it up to 90kts to push through the
headwind and the sink. Lost about 2,500ft making the jump but we were
rewarded with another nice climb farther in. (For those of you
unfamiliar with the structure of mountain wave, the wave generating
mountain sets off a series of ripples downwind, getting gradually weaker
as they stretch downwind. Running forward closer to the source will find
stronger lift.)

As the day went on we continued to work our way north and in. I think in
total we jumped in four times, ending up inside West Virginia and about
20nm away from home at the farthest reach. Our last jump also saw our
highest altitude, 11,100ft. Unwilling to keep pushing farther from home
(a Grob 103 is a cast-iron bitch to assemble, and my fellow club members
would have ritually sacrificed me to their god if I had landed it out)
and with the wave seeming to dissipate, I elected to turn for home.

On the way home, we bumped into another area of solid wave lift, with no
marker clouds to indicate where it was, and couldn't resist the
temptation to work it a bit. While we were doing that, we got the
long-awaited call from the ground that other club members were waiting
on the plane, so we hopped out of it, pulled spoilers to burn off the
7,000ft or so of remaining altitude before entering the pattern, and
landed. Total time in the air was 3 hours and 13 minutes.

All it all it was a wonderful confluence of events to have my brother in
town, to have such a great wave day, and to have a club two-seater
available for our use for over three hours (club limit is 1 hour if
anyone else is waiting to use it). I got to show my brother something
he'd never experienced before and give him new motivation to finish his
glider training, and I got to enjoy a wonderful day in wave for myself
as well.

For those interested, pictures can be had he

http://pix.mikeash.com/v/wave1109/

Commentary and constructive criticism are most welcome. Non-constructive
criticism of the type seen recently shall be met with great vengeance
and furious anger.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

On Nov 28, 10:59*pm, Mike Ash wrote:
Forgive the crosspost, but as both groups are low on relevant content at
the moment I thought it might be good to give both of them a boost.

My brother is in town this week for the holidays. He's with his
grandmother some distance away, but the gliderport is between us. He's
taken glider lessons up to solo and I thought that getting together to
fly would be a fun activity.

As chance would have it, the forecast for today was calling for wave. My
brother has done a lot of training, with tons of pattern tows, but very
little actual soaring. I figured that a nice wave flight would really
show him a totally new aspect to the sport.

Driving out to the airport, there were lennies stretching across the
sky, one after the other. Once there, I got everything ready as quickly
as I could. My brother showed up on time and we launched at about 10AM
in the club's Grob 103, hoping to catch the wave before it dissipated.

We towed through some fairly mild but still challenging rotor, then hit
a patch of what looked like wave lift at about 2,000ft above the
airport. Too chicken to try for it, I kept on tow looking to make it to
the next harmonic and a little higher before releasing. We spent what
seemed like a terribly long time barely climbing at all while on tow,
which I took to be a good sign (if air is going down, it must be going
up somewhere else!) and finally pegged the variometer coming out the
other side. Released into slightly chunky wave at 3,300ft above the
airport (4,000MSL) but soon established a solid climb.

The next three hours were some of the most pure fun and enjoyment you
can have. We had a solid climb up to about 9,000MSL averaging probably
3-4kts climb, and I introduced my brother to the basic ideas of wave and
how it all works. The lennies were scarce near the airport but more
solid to the north (northwesterly wind, so the wave bars were running
northeast/southwest) and we headed up that way.

After topping out the climb I got to teach my brother how to jump
forward to the next harmonic. Cranked it up to 90kts to push through the
headwind and the sink. Lost about 2,500ft making the jump but we were
rewarded with another nice climb farther in. (For those of you
unfamiliar with the structure of mountain wave, the wave generating
mountain sets off a series of ripples downwind, getting gradually weaker
as they stretch downwind. Running forward closer to the source will find
stronger lift.)

As the day went on we continued to work our way north and in. I think in
total we jumped in four times, ending up inside West Virginia and about
20nm away from home at the farthest reach. Our last jump also saw our
highest altitude, 11,100ft. Unwilling to keep pushing farther from home
(a Grob 103 is a cast-iron bitch to assemble, and my fellow club members
would have ritually sacrificed me to their god if I had landed it out)
and with the wave seeming to dissipate, I elected to turn for home.

On the way home, we bumped into another area of solid wave lift, with no
marker clouds to indicate where it was, and couldn't resist the
temptation to work it a bit. While we were doing that, we got the
long-awaited call from the ground that other club members were waiting
on the plane, so we hopped out of it, pulled spoilers to burn off the
7,000ft or so of remaining altitude before entering the pattern, and
landed. Total time in the air was 3 hours and 13 minutes.

All it all it was a wonderful confluence of events to have my brother in
town, to have such a great wave day, and to have a club two-seater
available for our use for over three hours (club limit is 1 hour if
anyone else is waiting to use it). I got to show my brother something
he'd never experienced before and give him new motivation to finish his
glider training, and I got to enjoy a wonderful day in wave for myself
as well.

For those interested, pictures can be had he

http://pix.mikeash.com/v/wave1109/

Commentary and constructive criticism are most welcome. Non-constructive
criticism of the type seen recently shall be met with great vengeance
and furious anger.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

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? 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. 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.

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?

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

Nice post.

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.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

On Nov 29, 12:19*am, 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.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

I would have expected the burble that causes the waves had to be
within a couple of thousand feet of the ridge altitude, but you got
rides to much higher than the mountains in WV -- ridge altitude plus
what -- 5 or 6000 feet? Neat stuff. You get to play in what we could
call 'fly through/over' conditions. I guess wave height has also a
lot to do with the ridge to valley distance on the upwind side.

My phone's navigational ability is limited to indicate "this way is
down" or at least "the local acceleration vector is pointing this
way". A ring tone that sounds like the middle marker might be fun:
"Answer or I'll announce the miss!" An ex marine I'm friendly with
somehow has programmed his cell phone to use a voice to announce a
call, but I think at Fort Bragg and elsewhere having a phone say
"Incoming!" would not be a good idea.

On 11/28/2009 7:59 PM, Mike Ash wrote:
Forgive the crosspost, but as both groups are low on relevant content at
the moment I thought it might be good to give both of them a boost.


Thank you, Mike. Relevant content is sorely needed here.

[ snip ]

All it all it was a wonderful confluence of events to have my brother in
town, to have such a great wave day, and to have a club two-seater
available for our use for over three hours (club limit is 1 hour if
anyone else is waiting to use it). I got to show my brother something
he'd never experienced before and give him new motivation to finish his
glider training, and I got to enjoy a wonderful day in wave for myself
as well.

What a great day indeed!

I remember the first flight I provided to a friend who was very afraid
of flying (and was trying to get over it). The conditions combined to
make an extremely smooth flying day (weather-wise) and he enjoyed the
flight a great deal - which made it a terrific flight for me as well.


For those interested, pictures can be had he

http://pix.mikeash.com/v/wave1109/

Commentary and constructive criticism are most welcome. Non-constructive
criticism of the type seen recently shall be met with great vengeance
and furious anger.

Well, or just ignore them :-) I think of them as unruly children who
don't get enough attention from their parents.

On Nov 29, 10:59*am, Mark Hansen wrote:
On 11/28/2009 7:59 PM, Mike Ash wrote:

Forgive the crosspost, but as both groups are low on relevant content at
the moment I thought it might be good to give both of them a boost.

Thank you, Mike. Relevant content is sorely needed here.

[ snip ]

All it all it was a wonderful confluence of events to have my brother in
town, to have such a great wave day, and to have a club two-seater
available for our use for over three hours (club limit is 1 hour if
anyone else is waiting to use it). I got to show my brother something
he'd never experienced before and give him new motivation to finish his
glider training, and I got to enjoy a wonderful day in wave for myself
as well.

What a great day indeed!

I remember the first flight I provided to a friend who was very afraid
of flying (and was trying to get over it). The conditions combined to
make an extremely smooth flying day (weather-wise) and he enjoyed the
flight a great deal - which made it a terrific flight for me as well.



For those interested, pictures can be had he

http://pix.mikeash.com/v/wave1109/

Commentary and constructive criticism are most welcome. Non-constructive
criticism of the type seen recently shall be met with great vengeance
and furious anger.

Well, or just ignore them :-) *I think of them as unruly children who
don't get enough attention from their parents.

The operative word for that class is "ignoranus". It bothers me that
some (supposedly) adults will act that badly to gain attention. It
doesn't say much for their egos, but this is not a forum for the
psychologically needy, it's for pilots.

In article ,
Mark Hansen wrote:

On 11/28/2009 7:59 PM, Mike Ash wrote:
Forgive the crosspost, but as both groups are low on relevant content at
the moment I thought it might be good to give both of them a boost.


Thank you, Mike. Relevant content is sorely needed here.

[ snip ]

All it all it was a wonderful confluence of events to have my brother in
town, to have such a great wave day, and to have a club two-seater
available for our use for over three hours (club limit is 1 hour if
anyone else is waiting to use it). I got to show my brother something
he'd never experienced before and give him new motivation to finish his
glider training, and I got to enjoy a wonderful day in wave for myself
as well.

What a great day indeed!

I remember the first flight I provided to a friend who was very afraid
of flying (and was trying to get over it). The conditions combined to
make an extremely smooth flying day (weather-wise) and he enjoyed the
flight a great deal - which made it a terrific flight for me as well.

Being able to share the joy does add so much to the experience. I will
confess that I was mildly annoyed that I wasn't able to take my own
glider (single-seater) instead and have fun on my own, but this was well
outweighed by the joy of sharing the experience.

For those interested, pictures can be had he

http://pix.mikeash.com/v/wave1109/

Commentary and constructive criticism are most welcome. Non-constructive
criticism of the type seen recently shall be met with great vengeance
and furious anger.

Well, or just ignore them :-) I think of them as unruly children who
don't get enough attention from their parents.

Ignoring them is probably what I'd do, but I can't resist the
opportunity to drop in a fun Pulp Fiction reference.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

In article
,
a wrote:

I would have expected the burble that causes the waves had to be
within a couple of thousand feet of the ridge altitude, but you got
rides to much higher than the mountains in WV -- ridge altitude plus
what -- 5 or 6000 feet? Neat stuff. You get to play in what we could
call 'fly through/over' conditions. I guess wave height has also a
lot to do with the ridge to valley distance on the upwind side.

Wave height is mainly related to the atmospheric temperature and wind
profile. I won't claim to understand how it works, but there's not a big
relationship between the mountain height and the wave height. Basically,
when wave is good, each layer of the atmosphere ends up perturbing the
layer above it in the same fashion, causing the wave to just go up and
up. I was up at 10,000ft this past June in wave, and that was about as
high as I was able to take it, but I could see obvious wave clouds at
what looked like 20-30,000ft. I know people who have been to well over
20,000ft in this area, including this fascinating and somewhat
frightening story that I was lucky enough to first hear in person from
that pilot:

http://wave99.info/info/article:the_price_of_a_jewel

The previous world altitude record in gliders was set in northwestern
Nevada, and achieved, I think, 49,000ft. The current record is 50,699ft,
set in the Andes. The Perlan Project (http://www.perlanproject.com/) is
currently constructing a pressurized glider that they hope will take
them to 90,000ft in Andes wave, and they believe that it goes higher
still.

My phone's navigational ability is limited to indicate "this way is
down" or at least "the local acceleration vector is pointing this
way". A ring tone that sounds like the middle marker might be fun:
"Answer or I'll announce the miss!" An ex marine I'm friendly with
somehow has programmed his cell phone to use a voice to announce a
call, but I think at Fort Bragg and elsewhere having a phone say
"Incoming!" would not be a good idea.

I have an iPhone, which has a built-in GPS. A couple of days before the
flight I decided that it would be good to be able to use it in flight,
so I wrote a little web app (which can be stored to the phone, since
there's usually no cell signal in flight) which takes the GPS output and
dumps it to the screen, plus some useful derived information like
distance and bearing to my home field.

Once I tested it in flight I discovered two bugs where I had screwed up
the unit conversions, causing my altitude readout to be off by about a
factor of 10 (showed 800ft when we were at 8,000ft) and my groundspeed
readout to be off by a factor of 4, but it was still handy, particularly
the "distance to home field" which I used quite a bit (with sanity
checks against the chart and local terrain... I don't trust my own
programming that much, especially after seeing those other errors) to
decide whether to press on deeper into the system.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

On Nov 29, 10:40*pm, a wrote:

I would have expected the burble that causes the waves had to be
within a couple of thousand feet of the ridge altitude, but you got
rides to much higher than the mountains in WV -- ridge altitude plus
what -- 5 or 6000 feet? Neat stuff. You get to play in what we could
call 'fly through/over' conditions. *I guess wave height has also a
lot to do with the ridge to valley distance on the upwind side.

The best wave is what we call 'Secondary wave' which is downwind from
the 'primary' wave.
Its more powerful and a lot smoother and can be quite a distance from
the 'primary' wave.
The bit in between is where you don't want to be :-)..

In article
,
george wrote:

On Nov 29, 10:40*pm, a wrote:

I would have expected the burble that causes the waves had to be
within a couple of thousand feet of the ridge altitude, but you got
rides to much higher than the mountains in WV -- ridge altitude plus
what -- 5 or 6000 feet? Neat stuff. You get to play in what we could
call 'fly through/over' conditions. *I guess wave height has also a
lot to do with the ridge to valley distance on the upwind side.

The best wave is what we call 'Secondary wave' which is downwind from
the 'primary' wave.
Its more powerful and a lot smoother and can be quite a distance from
the 'primary' wave.
The bit in between is where you don't want to be :-)..

I may just be revealing my ignorance here (and if so, would be glad to
have it corrected) but I thought the primary was generally the
strongest. Wave tails off as it gets farther from the source, so each
jump in tends to get you into stronger lift, with the best one being the
very first one after the generator.

Is it actually the case that the second one is stronger than the first,
and THEN it begins to fall off? It's possible, I'm certainly no expert,
but it doesn't match my fairly limited experience of wave flying.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon