Propeller Pitch On The Twotter

[Benoit 0]

Hi folks,

got the Twotter. So fun to fly. Landings are so cool with it. No any other aircrafts I flown have this cool behavior. Amazing Job Team!!

Just wondering, is only about movement effect. About propeller, what I find pretty cool is that when I move the pitch of it, the blades move, in the Acceleration P-51D by example (maybe the only one which does that). That looks like not simulated in the Twotter. Am I doing something wrong?

If not, if you want to note that for future project, I find that really cool, though we can't see this when the propeller is running, I agree.

Again, thx so much for this outstanding product.

Benoit.

[ross1562 0]

Propellor pitch is not simulated with this product.

[Benoit 0]

Roger!

Thx

Ben.

[Finn 873]

Propellor pitch is not simulated with this product.

More correct: Propeller pitch is not animated with this product !

The reason, apart from saving framerates, is that in the real twotter the props will move into feathered position on engine shutdown (Not on the float version though).

There is no mechanical linkage between the prop levers and the prop blades. Propblades are moved in pitch hydaulical through engine oil pressure. When the engines are shutdown there is no oil pressure and the prop blades moves to feather.

Finn

[twright 7]

More correct: Propeller pitch is not animated with this product !

The reason, apart from saving framerates, is that in the real twotter the props will move into feathered position on engine shutdown (Not on the float version though).

There is no mechanical linkage between the prop levers and the prop blades. Propblades are moved in pitch hydaulical through engine oil pressure. When the engines are shutdown there is no oil pressure and the prop blades moves to feather.

Finn

I've never really understood this about VP props. What does it look like in the feathered position? Is feathered where the prop blades are positioned completely side-on to the air? I noticed this as I boarded a DHC-8 Dash 8 a couple of years ago. Is full fine the opposite, where the blades completely face the air? Also I've travelled on various turboprop airliners and they all intermittantly make a wierd droaning sound during the taxi out - sounds a bit like a power saw - does anyone know what this is?

Thanks for a fine product!

Tom

[metzgergva 210]

Tom you are perfectly right. For the sound this is on taxi often as sounds change on props very much if the just windmil or actually produce thrust. It is interference between the blades depending on their pitch and speed of aircraft.

[Nick - Seria17hri11er 0]

I've never really understood this about VP props. What does it look like in the feathered position? Is feathered where the prop blades are positioned completely side-on to the air? I noticed this as I boarded a DHC-8 Dash 8 a couple of years ago. Is full fine the opposite, where the blades completely face the air? Also I've travelled on various turboprop airliners and they all intermittantly make a wierd droaning sound during the taxi out - sounds a bit like a power saw - does anyone know what this is?

Thanks for a fine product!

Tom

Here's what a feathered prop looks like mate;

http://images.google.com/images?q=feathere...sa=N&tab=wi

[Snave 466]

Tom you are perfectly right. For the sound this is on taxi often as sounds change on props very much if the just windmil or actually produce thrust. It is interference between the blades depending on their pitch and speed of aircraft.

To clarify this a little.

The free turbine as exemplified by the PT-6 family has no direct connection between the gas generator and the power take-off side except by the spinning of a turbine, driven by the gas generating section. It is this turbine that then drives the propellers via a reduction gearbox. This is what enables the turbine section to run at the very high rotation speed it needs, while not placing too much reliance on the gearbox itself which would otherwise have to convert 150,000 rpm to 1,000.

However this does mean that free turbines do show a very high residual thrust setting, even at ground idle. To cope with this the propellers on many turbines have a beta setting, somewhere below fine pitch, but above reverse thrust. This `beats` the fuselage and empennage and generates the characteristic drone, not the interraction between the blades themselves.