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Soaring on thermals

Posted: Tue Jul 03, 2007 1:11 pm
by skydiver
I was listening to an American podcast the other day, Ultraflight Radio it's called. A guy on it was talking about how he turns his engine off and rides the thermals for 2 or 3 hours. He is an instructor and maker of trikes and uses a very light machine. Down here, we tend to talk about not going up on bumpy days. do you guys soar in SA?

Posted: Tue Jul 03, 2007 2:14 pm
by nicow
Skydiver
We soar with gliders.A microlight is there for pleasure,and when it gets bumpy,we don't enjoy flying -except Dave Daniels in Natal.
Nicow
ZU-AWA

Posted: Tue Jul 03, 2007 2:35 pm
by Big-D
3 Crazy guys I know of

- Dave Daniels
- Dieselfan
- Tobie from FAAP


They like the rough air :shock: Personally I like it when it is 5degrees C and there is no wind


D

Posted: Tue Jul 03, 2007 3:07 pm
by Hot Stuff
With the wife on the back

Good fun

Posted: Tue Jul 03, 2007 5:48 pm
by ZULU1
It can be bumpy, but generally if you look for burnt cane, hot spots etc. I did Cato- La Mercy in 2 1/2 hrs the other day on 6 litres of fuel..just kept going up. when you get to the top of the "pipe" it can get interesting..

eish Zulu1

Re: Good fun

Posted: Tue Jul 03, 2007 6:15 pm
by DieselFan
ZULU1 wrote:It can be bumpy, but generally if you look for burnt cane, hot spots etc. I did Cato- La Mercy in 2 1/2 hrs the other day on 6 litres of fuel..just kept going up. when you get to the top of the "pipe" it can get interesting..

eish Zulu1
Have you fitted the turbo hks then Zulu1 :wink:

Seatbelts are a must, have only had 3 freakies, one dropping out thermal where seatbelt caught me and felt like I was airborne separately from the plane...and other at 7000 in the GF and climbing to 7500 with NO power and bar in all the way low hours around 35. :oops:

Be careful of flying too low I caught a weird one where my trike literally did a 270 without banking, I went back for the "object and the same happened again - surprise.

It's way fun but cruise control cannot be used as it's a seesaw effect. I haven't soared without engine tho.

Look out for wind conditions and direction, I was caught downwind of a powerstation that wasn't even that close, :roll: it's worse than what nature has thrown thus far and it wasn't even the large silos efforts... Felt fires aren't too bad but can give great boost and lift.

Flying close under clouds has been more bumpy than midday for me.

Proper soaring I've been told is like fuel from God.

Switching off motor..

Posted: Tue Jul 03, 2007 7:07 pm
by ZULU1
I learnt to fly in Swaziland years ago and thermals are a way of life, in tin aeries are not such fun, when I upgraded to trikes it was initially unpleasant and when you get; as Demon states correctly slowly rising broken clouds it gets really fun. Mountain winds (catabatic and anabatic) in early morning are sometimes interesting.

KZN North Coast is also good fun as the sugar cane dark patches and so on give great lift.
Just remember that rising hot air has a "jacket" of cold air moving in to replace the hot air, this gives sink that can bite you. Think of air as water and a river to get some ideas.

With my old 582 I could switch off and not worry. The HKS simply doesn't stop and is really very unpleasant on idle, it just windmills and pre ignites. It feels like some poor bearing is going to fall out. I used to do almost all landings dead stick but the HKS complains far too much. (Yes Diesel fan I am looking at a turbo)

Also really good fun is on the coast early morning such as Sodwana (just south of the lighthouse) which are the best dunes I have found yet, take all the weight out (seats panniers, no fuel etc) and surf the morning offshore up the sand dunes..fly from the ocean from 50 feet, up the dune and hit the lip, offshore wind gives awesome lift and wing over.
Better than thermalling. As a geriatric surfer its second best to the real thing.
Its actually best in a 503 Windlass with a cut down wing as they are a heap lighter, used to fly one out of Ladysmith and its the best yet for "soaring".

Lets be honest chaps nothing yet beats this kind of flying. I am sorry to say that three axis aeries don't have the ability to have this kind of enjoyment

Go experiment slowly and carefully the winds and you will enjoy as we do..

eish Zulu1

Re: Switching off motor..

Posted: Tue Jul 03, 2007 7:31 pm
by Rudix
ZULU1 wrote:I learnt to fly in Swaziland years ago and thermals are a way of life, in tin aeries are not such fun, when I upgraded to trikes it was initially unpleasant and when you get; as Demon states correctly slowly rising broken clouds it gets really fun. Mountain winds (catabatic and anabatic) in early morning are sometimes interesting.

KZN North Coast is also good fun as the sugar cane dark patches and so on give great lift.
Just remember that rising hot air has a "jacket" of cold air moving in to replace the cold air, this gives sink that can bite you. Think of air as water and a river to get some ideas.

With my old 582 I could switch off and not worry. The HKS simply doesn't stop and is really very unpleasant on idle, it just windmills and pre ignites. It feels like some poor bearing is going to fall out. I used to do almost all landings dead stick but the HKS complains far too much. (Yes Diesel fan I am looking at a turbo)

Also really good fun is on the coast early morning such as Sodwana (just south of the lighthouse) which are the best dunes I have found yet, take all the weight out (seats panniers, no fuel etc) and surf the morning offshore up the sand dunes..fly from the ocean from 50 feet, up the dune and hit the lip, offshore wind gives awesome lift and wing over.
Better than thermalling. As a geriatric surfer its second best to the real thing.
Its actually best in a 503 Windlass with a cut down wing as they are a heap lighter, used to fly one out of Ladysmith and its the best yet for "soaring".

Lets be honest chaps nothing yet beats this kind of flying. I am sorry to say that three axis aeries don't have the ability to have this kind of enjoyment

Go experiment slowly and carefully the winds and you will enjoy as we do..

eish Zulu1
Hi Zulu, interesting subject !

I agree it can be great fun using rising air to climb and extend a flight.

At first the bumps are a bit disconcerting but once you realize you can use it to your advantage it is FUN !

Ok, now I want to know why you say a 3-axis plane can't have this kind of fun ? Most 3-axis planes have better glide ratios and lower sink rates than trikes so in theory they will soar better, where they might lose out would be in "working" weaker lift that is normally smaller and requires tighter turns.

I have found that I can center my Rans quite nicely in even a weak winter high veld thermal by using more rudder than aileron in the tight turn thus keeping the wings more level, it is not strange to see climb rates of 800+ fpm with the engine at idle (1700 rpm) this time of the year. I have also used slope lift when flying upwind of hills with great effect, either to climb or to fly faster at the same throttle setting.

While flying from Kittyhawk to Petit Saturday at about 11am I managed to gain 1000 feet in just 3 circles in a thermal with the engine at low idle, if it was not for the TMA I would have gone a lot higher ! The engine at idle causes a lot more drag (prop disk) than the engine shut down so if you are high enough, and trust your engine enough, shut it down and you will be amazed. On the Rans the difference is more than 200 fpm sink rate.

Give it a try guys, lots of fun once you get over the feeling that the bumps are bad news !

Fly safe,
Rudi

3 Axis thermals

Posted: Tue Jul 03, 2007 7:46 pm
by ZULU1
I still fly and learnt to fly on tin planes...spose that I have had more fun in trikes. Maybe I am still going to buy that "doodlebug" I promised myself..

Any form of flying is still flying though, but cant do sand dunes in a 3 axis !!

I still enjoy a 503 Windlass no instruments and panniers...cut down wing..

eish Zulu1

Re: 3 Axis thermals

Posted: Tue Jul 03, 2007 7:57 pm
by Rudix
ZULU1 wrote: Any form of flying is still flying though, but cant do sand dunes in a 3 axis !!

eish Zulu1
I suppose that depends on the 3-axis, remember most "real" gliders are 3-axis :D

The soaring ability of a plane depends on its glide ratio, min sink rate (talking about LD ratio) and ability to turn tight without much height loss.

I agree the average tin does not have much chance of catching a thermal, or slope soaring a dune, but there are many 3-axis microlights that are good at this and will outperform a trike any day.

The long wing Challenger and Shadow's come to mind, people soar them for hours at a time. They are clean efficient planes with great LD ratios. And we are not even talking about Sambas/Lambadas/Whispers :lol:

Forgot one important thing,,

Posted: Tue Jul 03, 2007 8:01 pm
by ZULU1
You cannot thermal without an iPod...

Zulu1

Re: Forgot one important thing,,

Posted: Tue Jul 03, 2007 8:03 pm
by Rudix
ZULU1 wrote:You cannot thermal without an iPod...

Zulu1
:D I agree 100% :D

That reminds me, must still talk to you about that multi radio intercom !

Posted: Wed Jul 04, 2007 6:09 am
by Fairy Flycatcher
When we flew the Nationals last year, plenty of people had their engines off and flew like that for well over an hour (I think I was around 1hr 40 engine off, and grumpy around 2hours 20 engine idling :twisted: ). It is one of the standard tasks, so you will be surprised how many people are good at it. And there are plenty of people out there who fly the 'bumps'

Trikes can be great little thermal machines, but it also depends on the wing you use. The wing we fly with, the Aeros 14.8, behaves like a baby even down to 35mph, which means you can do much tighter turns and work much smaller thermals than with any light aircraft or glider.

In turbulence, the safest attitude to be in,in a trike, is about a 20degree bank - so using that thermal makes perfect sense. It takes some getting used to, and hard-rock over the i-pod is a definite help 8)

Remember to bank into the wing which gets lifted. This means some very aggressive flying, as the thermal tries to turn you away from the lift all the time. Thermals have a strong core, sometimes a couple of strong cores, with weaker lift around it. You have to constantly adjust your turn-radius to stay in it, until you have 'cored' it. Heaven... :D

Closed cockpits just don't come close. You become a bird, part of the sky. Gliders make me feel claustrophobic (although I will still get over it soon I hope), but there are some 3-axis which are almost as nice as a trike, like the Flightstar. (The Dragonfly glides like a brick :oops: :oops: )

Agree

Posted: Wed Jul 04, 2007 6:59 am
by ZULU1
I must agree Dave is really the best I have seen yet, ex hang glider pilots you see..just for info even in the winter of KZN you can still thermal. I did 4hrs 30mins on just over 20 litres on Saturday !!

As Annie correctly says though some wings are better than others and you have to know them well..

now i am going flying

Zulu1

Posted: Wed Jul 04, 2007 8:31 am
by Henni
Hi Rudi,

Is your Rans based at Kittyhawk? If so, won't you take me for a flip one day? Looks like a stunning microlight to me. Clean, light & full 3-axis!

Won't you please list your performance figures for this aerie?

Henni