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7/25/2019 44 50 Cloud Flying

2/844 CROSS COUNTRY CLOUDS

HeadClouds

IN

THE

What happens after cloudbase? Te perfect scenario is

you arrive, turn and set off on glide. But its not always sosimple. Some clouds try to suck you in, while others dont

let you near them. Sometimes its cold, dark and disorien-

tating, other times youll float up bathed in sunshine. We

asked three expert pilots for their advice...

7/25/2019 44 50 Cloud Flying

3/8CLOUDS CROSS COUNTRY 45

7/25/2019 44 50 Cloud Flying


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A cloud-filled sky in Araxa Brazil. Ondays like these you might spend quitea lot of your flight close to base and

thinking about avoiding going into cloud.Photo: Marcus King

ABOVE

Cloud depth is key when assessingclouds. One or two turns in a strongclimb in deep cloud is enough to get youcompletely lost, says Olympio.Photo: Fredrik Gustafsson

Olympio, thinking about flatland flying, do you

have any rules of thumb about climbing to base

and avoiding cloud?

Cloud flying in the flats, although less criticalthan in the mountains, is still dangerous because

of the possibility of loss of orientation, deep stall

and collision with other gliders or aircraft. Not

to mention overdevelopment and the associated

death risks.

Before flying I usually look at the forecast

of cloud depth. (Cloud depth also works as an

indicator of potential overdevelopment.) XC Skies

and other weather sites have cloud depth charts.

While flying I look at the clouds to have an idea of

how deep they are. Te deeper they are in a given

day the more conservative is my approach to cloud

flying. It is usually not a problem to fly in shallow

clouds; on the contrary, it can be a lot of fun. Deep

clouds, on the other hand, can become a problem.

If I am climbing under a deep cloud and I am farfrom its edge I usually leave the core I am climbing

in before I get to base so as Im closer to the edge.

Te closer I am to cloudbase the closer I want to

be to the edge of the cloud so as to allow for a safe

escape. (If upon approaching the edge you leave

the climb by accident you can always go back to

it. On the other hand, if you allow yourself to be

sucked in you are left with no option but to look

for an exit.) In most cases, even if you opt for the

edge of the cloud you will still fly into it, but it will

be easier and faster to find your way out. Going

into a deep cloud far from its edge is very likely to

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OUR PANEL OF

EXPERTS

Olympio Faissol

Brazilian flatland expert. On 22

October this year he flew 462km

from Quixada, his second 400km of

the week.

Kelly Farina

An Alpine paragliding guide based

in Austria, Kelly regularly guides

courses in the Zillertal Valley and the

Dolomites (www.austrianarena.com).

Adrian Thomas

A competition pilot and twice British

Paragliding Champion, Adrian is a pro-

fessor at Oxford University where he

researches the biomechanics of flight.

CLOUDS CROSS COUNTRY 47

get you lost, which in turn may lead to a delayed

exit and possibly a scary experience too.

Kelly, youre an Alpine pilot. Whats your rule of

thumb?

A question Im often asked is, How close can you

get? Te simple answer is it depends on the size of

the cloud. Being nervous of big clouds is healthy

and there is limited longevity in taking risks. I

am a big advocate of prevention rather than cure:

thinking ahead instead of needing some funky

ninja move to get out of danger. Tis is especially

true when cloud flying.

One rule I pass on is the Forty Five Degree Rule.

Tat is, keep the edge of cloudbase at 45-degrees

to you. Our airspeed at trim is around 10+m/s,

so if the climbs turn into 10m/s it will give you a

1:1 glide to the edge (10m/s forward and 10m/s

vertical speed). You should kiss the edge of the

cloud as you leave.

Tere is no downside to this rule. If pilots find

the lift gets too weak they can always creep back

under a big cloud. However, the pilot who is too

deep and too close when things get strong will

soon find themselves lost. Not a nice situation. It

works also for streets and clouds up to any size

within reason. Surfing up the 45-degree line and

back down in sink then back under to ride the

45 again is something I call barrel rolling. Way

quicker than any ninja move that will make you fly

at 90-degrees off track to escape the clutches of a

wet, dark and strong thermal top.

A lot of people take a turn or two into cloud. What

do you think about this? Good or bad practice? Or

depends?

Kelly:It depends on the size of cloud and where

you enter. If just at the edge then its not a

problem. I make sure I can always see the sun if

going into a cloud. Sometimes, if the cloud is just

mist and I am alone I will turn many times through

the fog, but only if the sun is always visible above.

Tis lets you know its not that dense. However

once you lose the sun it is very likely youll getdisorientated very quickly.

Olympio:It depends on your position in relation

to the cloud as well as on cloud depth. One or two

turns in a strong climb associated with a deep

cloud is enough to get you completely lost for

several minutes. If you are close to the edge of the

cloud and there are not many gliders around you it

is usually no problem. Obviously, in gaggle flying it

is always dangerous to take extra turns and go into

a cloud, hence the heavy penalties for cloud flying

in competitions.

Tis may be an obvious one, but what are the

problems associated with flying in cloud, or very

close to cloud?

Olympio: In the flats number one is

overdevelopment. We have all read the horror

stories of pilots who were caught in CBs. In days

in which there is potential for overdevelopment

I usually set a very wide margin of safety when

deciding whether to land, especially as two-liners

do not spiral well.

Deep stalls are also common. I know of a few

cases of pilots who experienced deep stalls because

they went into big clouds, either to stretch the

next (usually final) glide or just for the heck of it.

Getting your glider wet is a dangerous practice,

especially if you are flying two-liners. It should not

be done.

Other potential problems are collision and

loss of orientation, which delays your flight and

compromises effective navigation.

Kelly:he main one is disorientation. If its

a big cloud on a spring day pilots could easily

find themselves climbing in all directions. If

lucky theyll pop out the side a few hundred

metres above base. But if pilots play with fire

in the middle of a Congestus cloud they could

find themselves above 6,000m with iced lines

and terribly cold. Remember that its turbulent

inside a big cloud it can be tricky to even

maintain direction.

Clouds that form lower than the surroundingpeaks are dangerous for an entirely different

reason: crashing into the mountain becomes a

real possibility.

Personally, if the sky is so overdeveloped that

I cant stay out of clouds I will land as I am more

worried about the cold air and rain falling out

of overdeveloped clouds. Alpine valley systems

are perfect funnels for this cold, shallow flow.

Once venturi takes over its anyones guess as to

the wind in the bottom of the valley. here will

always be another day.

Are there safe clouds that you would climb in, and

unsafe clouds that you avoid?

Olympio:Again, cloud depth is key. Deep clouds

are more dangerous, because you are more likely

to have a delayed exit if sucked in and get your

glider very wet in the process. Position in relation

to the cloud is also key: it might be safe, for

example, to climb under an isolated congestus

provided you are close to the edge and have a safe

escape route.

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IN THE THICK OF IT

Sometimes, base is a bit dark. This pilotmight need an umbrella quite soon. Youdont want to get your glider wet as somegliders have a deep stall problem whenwet. If you get rained on or you get wet incloud, get on bar and fly until the gliderhas dried out. Photo: Martin Scheel

If you start to get sucked in, what advice do you

have for getting out quickly?

Olympio:Before you get sucked in it is good to

have a point downwind in your GPS you can fly

to. Unless you have a big compass it is better to

look at the compass page of your GPS and fly

downwind towards that point (use the accelerator

when possible). It is very easy to lose your bearing,so it is important to concentrate on maintaining it

in order to fly straight. Cloud flying without a GPS

can become an agonising experience. Attention to

sunlight may also help as it indicates areas of less

density. Unless the climb is weak always opt for a

horizontal escape as opposed to a vertical escape

like spiralling or B-lining.

Adrian:Spiralling or B-lining or full-stalling all

have you descend in the same place. A thermal

has inflow, particularly close to a sucking cloud

where thermal strength is increasing. If you spiralor B-line or full-stall you will be sucked gently

towards the strongest updraft and will stay there.

Much better to fly in a straight line and get out of

the updraft. Even in the strongest cloud-suck the

updraft region is small, and there is sink nearby. It

is very rare indeed to have an updraft more than

a kilometre across. Even if you head the wrong

way across such a monster updraft you only have

to fly 1km to get to the other edge at the absolute

maximum, and at trim speed that is going to take

you a little less than two minutes, provided you fly

in a straight line.

Tat is the key: fly in a straight line (in any

direction) and you will get to the edge of the

updraft. Obviously it is a good idea to fly towards

the nearest edge of the cloud, but even if you are

totally disorientated if you fly in a straight line you

will exit the cloud.

Flying in a straight line in cloud is hard, since

there are no visual references. You need to haveinstruments you can rely on, and need to believe

what they tell you (its too easy to think the

compass is lying). I find that it is entirely possible

to follow the arrow on a GPS and fly reasonably

straight in cloud, but it is much easier to use a

compass. I use a cheap Silva orienteering compass

big expensive gimballed things are unnecessary.

Even those joke keyring compasses give good

enough information for what you need, which is

just to keep flying in roughly the same direction

for a minute or two. It is very easy to get very

disorientated in cloud. Ive emerged from cloudconvinced I was going straight to find the world

turning below me. You really need an instrument

to guide you out of cloud!

Kelly:If you use the 45 degree rule things have to

get pretty out of hand to get sucked inside. But if

pilots overcook it I would recommend Big Ears,

speed bar and make yourself as big to the airflow

as possible, stand up if necessary. Hold your course

and hope for the best. If deep in then a spiral

may be useful until you can get to the 45 line. It

may take a while and steep spirals have their own

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Why on some days does the lift slow down get-

ting to base, and on others the lift gets stronger

as you get to base?

Generally, if the day is unstable and clouds are

tall it will be easy to get to base and on into

the white-room if you want. On stable days,

blue or with haze-domes or f lat clouds, par-

ticularly with an inversion limiting thermal tops,you may find climbs slow as you get towards

cloudbase.

What happens when the climb goes into the

cloud. What's going on?

As the water vapour condenses to droplets it

releases heat (we are more familiar with the

opposite movement of heat when sweat

evaporates it cools you down the same

process going in opposite directions). That heat

warms the air, which can re-energise the thermal

increasing the climb rate. It is not unusual forthe climb rate in a thermal to double once you

go into cloud.

I've often heard people say lift gets turbulent

inside clouds. Why is this?

Because of the extra energy being released by

water vapour condensing to cloud droplets.

Technically, is there a difference between strong

lift and cloudsuck?

Fundamentally, there is no difference.

Clouds are wet. What should I be aware of

about flying with a wet glider?

The issue is that some gliders have a deep stall

problem when they get wet. Deep stall is difficult to

recognise if you are not used to it, and can be hard to

recover from. If you get your glider wet then it is re-

ally important to keep the airspeed high. Get on the

bar, and stay on the bar until it has dried out again. Ifthat means until you land, stay on the bar all the way

down the last thing you want is to get a deep stall

close to the ground. Don't muck about with this one:

two people threw their reserves during the practice

days at the Europeans this year after their gliders got

only slightly moist.

Climbing up cloud on the outside is amazing...

Climbing up the side of a cloud is an absolute

privilege, so make the most of it. The trick is to

maintain constant awareness of what the cloud

is doing, and always move to clear air as soon ascloud starts to build around you. Sometimes you

can surf up the upwind sides of clouds because

the thermal forming the cloud is blocking the wind

to some degree, so the cloud behaves like a giant

hill. Sometimes wave is involved. In the Alps there

is generally some sort of convergence going on,

with drier air on one side and moister air on the

other like sea breezes and then the trick is to

stay in the dry air.

WHAT DO THE CLOUDS FEEL LIKE?

Adrian Thomas on the technicalities of clouds

7/25/2019 44 50 Cloud Flying


ON THE EDGE

Staying well clear of the white stuff.

Photograph: Fredrik Gustafsson

dangers. B line stall is an outdated method it will

be too slow and you have no real control.

When climbing under a cloud, how do you work

out where the strongest part of the cloud is?

Wheres the sweet spot, wheres the danger zone?

Kelly:Te danger zone is anywhere within the 45

degree cone (single cloud) or 45 degree edge if a

street. Upwind edges are usually the best, and youcan sometimes see from underneath where the

cloud is darker, as that is the deeper part of the

cloud. (Clouds are always white, it is just dark due

to height and/or density.) When close you can also

see tendrils, with experience these even tell you

how strong the climb will be.

If there is a street along a ridge it is sometimes

unwise to be trapped between the wall of rising

air and the peaks themselves, as you have to go

through the climb again to reach the safety of the

valley floor.

At base it can be easy to get confused about

direction. How do you tell where the next cloud is

and which way you should leave?

Olympio:Looking at the cloud shadows is

an option. I usually decide where I want to

head before reaching base. If I get sucked

in, I concentrate on maintaining my bearing

unchanged, unless I see sunlight on one of my

sides (which may be an indication of an exit).

Kelly:Again, thinking and planning on the climb

is king here. Making your next chess move whilst

climbing is infinitely better than being spat out of a

climb high up with no idea where to head for next.

Finally, can you tell us what your personal rule is

for flying and cloud and why?

Olympio:I for my part fear big clouds. Luckily

I never had any really bad experiences because I

always managed to escape before it got too hairy.

All of my experiences of cloud flying were verygood ones, surfing their edges, getting out safely

and not fearing the worst. But as a general rule, I

avoid it.

Kelly:When the air is strong and deep and large

cumulus are over the peaks I tend to always avoid

flying in cloud as I just dont like it. In the early

years I got sucked in a few times but in strong air it

can be quite unnerving. If in doubt, I leave earlier

rather than later.

Adrian:I have played a lot with cloud-flying in theUK (where it is, according to the NAC, legal), and

have come to the conclusion that it really doesnt

help with XC flying unless the distance between

clouds is beyond glide-range, and even then its

marginal. Te problem is that while you are in

cloud you have no idea what is going on around

you, so you emerge from cloud and have to make

an instant decision about where to go. Better to

keep an eye on the next route options as you

approach cloudbase, and kiss the wispies as you

leave. Of course, playing with cloud for the sake of

playing with cloud is just magic.

SUCKED IN

I followed a bunch of Turkey vulturestowards a cloud once, and watchedthem go straight under the dome ofthe cloudsuck, and straight up intocloud. Never seen birds do that before.I was a little behind and below so Iheaded for the edge of the cloud, andI could see by the ground shadow thatI was only a few hundred metres fromthe edge. Didnt make it. Got suckedin. Picked a compass direction andheaded that way, steadily climbing at4m/s with Big Ears and half bar star-ing at the compass. Fifteen minuteslater I emerged into a cloud-canyon,some 900m higher than I had gonein, having done 12km in a straightline. I surfed down the canyon in theclouds and popped out into the bluevery relieved. When I looked back thatcloud had gone from the little roundcumulus Id followed the birds into to amassive CuNimb. I glided straight onuntil I landed, then sat and watched the

lightning show. Adrian Thomas

44 50 cloud flying

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