Using thermals to climb?

Im surprised Dylan hasnt weighed in yet... He used to talk about doing
it (somewhat) in the Cessna 140 he used to be part owner in. He was a
member at a local soaring club as well as the flying club that I had met
him in

His page, which is not very up to date, is
http://www.alioth.net/flying/soaring/index.html and may have some
information with regards to thermalling. The main concern as I've had
related to me is that to stay in the thermal you need to fly tight and
slow. Remember your stall speeds in steep banks/high G turns go UP.

My best guess would be to try a best angle of climb tactic, with short
field flap settings and give it a go.

As for doing this on a XC trip, I dont see a whole lot of point to it..
unless you are in SLC and need to climb up out of the bowl there.

Dave

Kees Mies wrote:
Hi All,

I need some advise.
The summer is starting and my plane is a rotten climber, certainly on
hot days at MTOW.
The best it can do in these conditions is about 300fpm.

My idea is to use thermals to climb (much)faster like gliders do.
Is this a stupid idea?
If my idea is not that stupid how do I find thermals and how to use
them properly?

Maybe I should have asked this on a soaring site but I think there are
a lot of pilots flying both kinds of planes.

BTW, my plane is a MS880 Rallye.

Thanks,
Kees.
D-EDMB.

Richard,

My advice is to forget about it,


Well, on a hot day in Prescott, AZ, it made my day in a BE35 - so I
wouldn't know why to forget about it.

--
Thomas Borchert (EDDH)

Michael,

That's ALWAYS the safest option.

Not if you drive instead g.


You know, some of us fly entirely without engines - and we fly cross
country.


You know, I hold a glider rating...

--
Thomas Borchert (EDDH)

(Kees Mies) wrote in message . com...

Hi again,

Thanks for the information about using thermals.
I don't think I'm going to try it.

Let me explain.
I asked this question because I've a personal danger zone that goes
from 1000ft AGL to 2000 ft AGL.
Lots of light aircraft use these heights over here, normally I cruise
at 2000ft to 2500ft AGL. I bit quieter and still low enough to see
details on the ground.
I'm one of those (rare???) pilots that solely navigate by watch,
compass and map.
Well, I've to because my plane doesn't have things like VOR or ADF.
The original plan was to stay at 1000ft, find a thermal en route and
soar to my cruising height.

After reading all the replies it means making steep turns close to
stall speed at low altitude.
Sounds too dangerous to me, I'm not going to endanger a passenger,
people on the ground or myself just to climb a bit faster.
Did something like this as a student pilot on a solo XC to another
airfield.
Turned from base to final, to prevent an overshoot I pushed a bit
harder. Hearing a stall warning at 400ft above ground in a 45 deg turn
is something one does not forget easily.
Anyway, I didn't end up as a statistic and I learned from it.

I've to learn to be more patient when climbing.

Happy landings,
Kees.
D-EDMB

In article , Kees Mies wrote:
Hi All,

I need some advise.
The summer is starting and my plane is a rotten climber, certainly on
hot days at MTOW.
The best it can do in these conditions is about 300fpm.

My idea is to use thermals to climb (much)faster like gliders do.
Is this a stupid idea?

No, not at all.

Get some experience in a glider so you know and have felt the various
sources of lift that are available.

I used to own a half share in a Cessna 140. It had an 85hp engine and a
cruise prop. Even at sea level, getting much more than 300fpm climb was
asking a lot in that plane.

I flew that plane coast to coast in the United States. That meant doing
things like crossing the Sierra Nevadas, and taking off from airfields
at nearly 6000' MSL. Knowing what sources of lift were avalable (and as
a corollary, where the sink was likely to be) really helped climb. For
example, coming out of SLC and needing to be above the mountains by
Provo, I used upslope lift to help the climb rate. Doing a photo shoot
over the Wasatch range was a much quicker job because there were some
good thermals, and the C140 can be flown slow enough to take good
advantage of them.

If you are flying a plane without much power, glider experience can come
in very handy indeed especially at high altitude.

--
Dylan Smith, Castletown, Isle of Man
Flying: http://www.dylansmith.net
Frontier Elite Universe: http://www.alioth.net
"Maintain thine airspeed, lest the ground come up and smite thee"

"Richard Hertz" wrote:

It isn't the glide ratio that one is concerned with in thermals - rather the
minimum sink rate and the speed for minimum sink.

You've got too much glider time :-) In a glider, you want
to thermal near min sink speed. In an airplane, you want
max excess power, and that's Vy, max rate of climb.
However, at Vy in most aircraft, your turn radius will be
quite a bit larger than most thermals, so you end up trading
off turn radius for climb rate if you're going to turn in
thermals. You'd probably only want to do that if you're
trying to get over a mountain pass. As others have posted,
most of the time you just want to use the free energy that
thermals give and to do that, you slow way down and spend
time in rising air, dive through sinking air and fly the
cloud streets.


Usually thermals are fairly localized and glider pilots work a lot to stay
in them. Turns are routinely done by banking between 30 and 60 degrees at
slow relatively slow speeds.

To do this right you need to find your minimum sink speed. Take some glider
lessons and you may get good enough to make it worth worrying about, but I
doubt you can make it work well in a power plane.

If on the other hand you can find some nice ridge lift or wave, then you can
save some gas.

The varios on gliders are generally quite sensitive and finding a thermal in
a power plane is not going to be trivial. Especially if you want to go
someplace.

My advice is to forget about it, but if you are curious, take up soaring -
it is a lot of fun and will improve your piloting skills and knowledge.

It's an effective technique for increasing cruise speed,
reducing gas usage and for climbing to cross high terrain.
Todd Pattist
(Remove DONTSPAMME from address to email reply.)
___
Make a commitment to learn something from every flight.
Share what you learn.

(Kees Mies) wrote:

After reading all the replies it means making steep turns close to
stall speed at low altitude.

You don't need to turn in thermals to use them. Just slow
way down when you feel the upward acceleration, speed up as
you enter descending air and follow the cloud streets as you
get higher.

Todd Pattist
(Remove DONTSPAMME from address to email reply.)
___
Make a commitment to learn something from every flight.
Share what you learn.

(Kees Mies) wrote in message . com...
My idea is to use thermals to climb (much)faster like gliders do.
Is this a stupid idea?
If my idea is not that stupid how do I find thermals and how to use
them properly?

To add to the replies already on this interesting thread:

1. As Kees noted in his last post here, efficient thermalling requires
steep banking near stall. If you do that, make sure your ship is
benign in its stall or that you have plenty of altitude to recover and
know how. Playing areas of lift by slowing down and then speeding up
in sink will make for a more efficient flight without thermalling,
though here too "slowing down" can mean approaching stall. I
frequently "commute" between the San Francisco Bay Area and Minden, NV
in a motor glider and have noticed frequent long wave type lift across
the Central Valley. I'll go for about a mile with about 100 fpm (1/2
m/sec) lift -- not enough to climb (engine off), but enough to more
than double my normal glide ratio (50:1) -- followed by the same
distance with about 100 fpm of sink. Slowing down and speeding up
stretches my glide and reduces my engine run times a bit. Plus it's
fun.

2. Someone noted the need for a variometer as opposed to a
rate-of-climb meter. While the faster response time of the vario would
help, I was able to thermal my glider when I first got it (sans vario)
using just the ASI. Watch for a sudden increase in air speed to
indicate entering lift. The seat of the pant feel and which wing
lifts, as already noted, also help.

3. Try to learn where the "house thermals" are. Glider operations,
which fly out of the same airport all year, learn where these are and
convey the info to tow and glider pilots. While there may not be a
glider operation at your airport, there are likely to be house
thermals that you can learn about.

4. A lot depends on where you are. During the summer, lift at Minden
can be over 1000 fpm, but on the same day, there can be almost no lift
at my home base (Hayward, near Oakland and SFO). The marine air in the
Bay Area kills most thermals.

5. Centering a thermal is a skill, though one more easily learned than
most people (myself included) might think before they learn it.
Levelling out for a few seconds when you enter the area of increased
lift is the usual method, but in really small thermals (or if your
stall speed is so high you can't stay in a normal sized one) there is
a seemingly contradictory technique that also works. As soon as you
hit the lift, bank steeply (but don't stall/spin!) and raise the nose
agressively (ditto), much as a swallow might do. This keeps you in the
area of lift longer. And, since you can't stay in it for the whole
circle, you don't want to be centered since that would put you into
reduced lift or, worse, sink. Being centered while going down isn't
the goal.

Hope this helps.

Martin

wrote:

1. As Kees noted in his last post here,
efficient thermalling requires steep
banking near stall.

Almost all replies to this topic have given the impression that the steeper the
better -- that's not *always* true. Depending on the size and strength of the
thermal, sometimes banked a little less makes more effective use of the lift,
exposing more of the surface of the aircraft to the rising air.

--Shirley
Glider Pilot

Yes. But if climbing while making cross country speed and distance is the
objective, the best climb is accomplished with wings level. A powered
glider of *any* sort is capable of exploiting this when going cross country.

Just as any cross country glider pilot strives to 'climb straight ahead' as
much as possible, it is an optimal technique for a powered a/c in cc flight.
In point-to-point flight in a field of thermals, the fastest or most
efficient path is *not* a straight line or is it in level flight.

Go glider pilots!!

"Shirley" wrote in message
...
wrote:

1. As Kees noted in his last post here,
efficient thermalling requires steep
banking near stall.

Almost all replies to this topic have given the impression that the
steeper the
better -- that's not *always* true. Depending on the size and strength of
the
thermal, sometimes banked a little less makes more effective use of the
lift,
exposing more of the surface of the aircraft to the rising air.

--Shirley
Glider Pilot