Author Topic: New category  (Read 16938 times)

Offline Frank N. O.

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Re: New category
« Reply #30 on: June 02, 2006, 06:56:14 PM »
Gulf I must've forgotten to reply to this, last I asked then she said it did have a small enclosure and instruments so it probably wasn't a hang-glider-wing but I'll try to ask her again later.

Fliboye: Thank you very much for that detailed explanation, that was very informative and I like information about vehicle technology :)

Frank
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."
Leonardo da Vinci

Offline ZAIZAI

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Re: New category
« Reply #31 on: July 20, 2006, 09:07:48 PM »
Yes, feathering is used only in real emergencies.

Eh? A diver driver that I have tons of respect for, he is top dog in the Swedish Air force (I could kill for his job, some of the time), anyway he feathers the prop (DHC-Singel Otter, turbo prop) when loading jumpers. Darn the thing turns so slowly you can count the blades!

Have a question(s) about turbines and turbo-props. I know how a gas-generator work but how do you transfere the energy produced to the prop? In thrustor jets I understand the concept, but it gets a bit hazy for me when a prop is involved.

-Helicopters, is the main rotor shaft, power turbine and gas generator physicly connected to each other or is the gas generator rotating freely supplying gas to the power-turbine which via a reduction gearbox supply power to the rotorshaft? Is the gas-generator and powerturbine on the same rotating spindle or are they not joined?

-Turbo-props, same question really?

-Are there any instances where the powerturbine is hanging on the same shaft as the gasgenerator? Not jets...

« Last Edit: July 21, 2006, 07:49:00 PM by ZAIZAI »
...Lurker...
I don't need an engine and a prop for my Skyarrow anymore...but I do need a testpilot for it. Chuck wanna step up?...on second thought, perhaps not.

Offline Mike

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Re: New category
« Reply #32 on: August 12, 2006, 06:54:19 PM »

Eh? A diver driver that I have tons of respect for, he is top dog in the Swedish Air force (I could kill for his job, some of the time), anyway he feathers the prop (DHC-Singel Otter, turbo prop) when loading jumpers. Darn the thing turns so slowly you can count the blades!

Have a question(s) about turbines and turbo-props. I know how a gas-generator work but how do you transfere the energy produced to the prop? In thrustor jets I understand the concept, but it gets a bit hazy for me when a prop is involved.

-Helicopters, is the main rotor shaft, power turbine and gas generator physicly connected to each other or is the gas generator rotating freely supplying gas to the power-turbine which via a reduction gearbox supply power to the rotorshaft? Is the gas-generator and powerturbine on the same rotating spindle or are they not joined?

-Turbo-props, same question really?

-Are there any instances where the powerturbine is hanging on the same shaft as the gasgenerator? Not jets...


I am not a turbo prop of much of a fixed wing guy but our SEAT's here at the base (single engine air tankers) run turbo props and one of them (the one with the Pratt&Whitney engine) puts his props into feather when he is idling and getting loaded with retardant to not blow the ground crews away when they load him. I am assuming that's what your buddy is doing when he is loading jumpers.....
There is no real problem with the feathering since the engine is not direct drive. It might get warm a little because the power turbine might turn a lot slower than the gas producer.

On helicopters the gas producer and the power turbine is not mechanically connected as well (you couldn't start it unless you'd put in a seperate clutch) and they link up later at full speed only by what is called "gas coupling" when the essentially turn the same speed or close to it.
The gas producer and the power turbine are usually two drive shafts with one of them being hollow and the other one turning inside the first one without any mechanical connection between eachother.
That way you don't need a clutch when you start the engine. You speed up the gas generator with its compressor wheels and its turbine wheels and the power turbine is just another wheel you "hang" in there to drive something with it (in case of the helo, the gearbox that drives the rotor).

I hope I explained that ok. ;D
Sorry for responding so late. I can't always check out all the threads. If you have any more questions, fire away!
I am ready!
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Offline Frank N. O.

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Re: New category
« Reply #33 on: August 20, 2006, 02:47:02 PM »
After reading about the ladybug in the pitot-tube then I'd like to ask something (while hoping it hasn't been replied to here before).
In flightsims there's usually a switch named alternate static, is that related to the pitot tube for the instruments relying on vacuum or am I mixing a lot of things together?
And why is the pitot-tube usually on the leading edge on the wing and not the nose, is that so the pilot can check it visually (since I've often seen it placed on the left wing).

Greetings
Frank
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."
Leonardo da Vinci

fireflyr

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Re: New category
« Reply #34 on: August 20, 2006, 03:46:15 PM »
After reading about the ladybug in the pitot-tube then I'd like to ask something (while hoping it hasn't been replied to here before).
In flightsims there's usually a switch named alternate static, is that related to the pitot tube for the instruments relying on vacuum or am I mixing a lot of things together?
And why is the pitot-tube usually on the leading edge on the wing and not the nose, is that so the pilot can check it visually (since I've often seen it placed on the left wing).

Greetings
Frank
[/quote
Good question Frank, |:)\
The pitot tube is generally located on the wing on single engine aircraft so as not to be affected by propeller wash---it supplies ram air, the pressure of which expands a bellows device which in turn operates the airspeed indicator needle so it needs to be in an area of undisturbed airflow to give an accurate reading. Multi engine airplanes generally have the pitot mounted on the nose.  The static side of the A/S indicator, rate of climb indicator, and the altimeter are routed to an outside area of the aircraft where the pressure is neutral and the alternate static source (which vents the instruments to the cabin) is to be used if the static port becomes plugged.   On aircraft without an alternate static source, the glass on the rate of climb instrument can be broken as a field expedient if the static port becomes plugged.   In 40 plus years of flying, I have never experienced a plugged source of either, but it can happen and a pilot should be aware of the potential and be able to fly the airplane (VFR) in that condition.   That's another good reason why instructors should teach with the panel covered (again VFR).
Hope this helps and I'm sure some sharp instructor will correct my simplistic explanation. 8)
Jim

fireflyr

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Re: New category
« Reply #35 on: August 20, 2006, 03:48:05 PM »
How the heck did I quote myself in the previous post----DUH!!!! :-\

Offline Frank N. O.

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Re: New category
« Reply #36 on: August 20, 2006, 03:49:56 PM »
LOL thanks for the reply. I think the problem is that there's one (quote) too many in the text.

Frank
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."
Leonardo da Vinci

Offline spacer

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Re: New category
« Reply #37 on: August 21, 2006, 02:40:37 AM »
If the chambered wing spelling is correct, and it is a powered 'chute, they do have some really
elaborate chassis for those things nowadays. A windscreen isn't farfetched at all, and a bunch of 'em
look kinda like brightly painted flying dune-buggies. Some have bodywork, though I've never seen an
entirely closed cabin, but I wouldn't put it past some folks to try it. I guess it'd take the open-air charm
out of it, and at 30mph or so, that's really what it's all about.

fireflyr

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Re: New category
« Reply #38 on: August 21, 2006, 11:02:59 PM »
If the chambered wing spelling is correct, and it is a powered 'chute, they do have some really
elaborate chassis for those things nowadays. A windscreen isn't farfetched at all, and a bunch of 'em
look kinda like brightly painted flying dune-buggies. Some have bodywork, though I've never seen an
entirely closed cabin, but I wouldn't put it past some folks to try it. I guess it'd take the open-air charm
out of it, and at 30mph or so, that's really what it's all about.

HUH ??? ???

Offline Frank N. O.

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Re: New category
« Reply #39 on: August 22, 2006, 12:20:34 AM »
Thanks for the info :)

Jim: In case the ?-mark was why he typed this then I'm sure he's replying to a question I asked a while ago in this thread about the flying machine my best friend Chey had solo'ed in but the description she could remember kind-of contradicted the std. types of ultralights but he could now say that there were all kinds of variations on the types.

Frank
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."
Leonardo da Vinci

Offline spacer

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Re: New category
« Reply #40 on: August 22, 2006, 03:47:44 AM »
Chamber-wing... a parafoil with chambers which inflate when you get a little airflow into them.
The term may not be 100% accurate, but IIRC it was.

fireflyr

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Re: New category
« Reply #41 on: August 22, 2006, 12:51:35 PM »
I gotcha!!!, thanks ;D

Offline happylanding

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Re: New category
« Reply #42 on: August 23, 2006, 04:25:05 PM »
What the hell is that?!?!? A kind of redbull strange things flying competition winner????????????????????????
I give that landing a 9 . . . on the Richter scale.

fireflyr

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Re: New category
« Reply #43 on: August 25, 2006, 02:33:22 AM »
What the hell is that?!?!? A kind of redbull strange things flying competition winner????????????????????????
No my little Alpine Alice---it's merely a way some folks get thier kicks in the air (not me though) ;D

Offline Frank N. O.

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Re: New category
« Reply #44 on: August 25, 2006, 06:05:12 AM »
LOL Alpine Alice. I got a reply from Chey on the subject when I asked if it looked like the above picture:
"No, two-seater, side-by-side, high-wing pusher. No body, just framed, except for a small windscreen above the instrument panel since Turlock has lots of insect activity :D
very much like this, except for the single seat and no windscreen"
http://web.mit.edu/dtan/www/Quicksilver.jpg

Frank
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."
Leonardo da Vinci