Propeller magic

Most us us are familiar with the "optical"effect when frame rate and frequency and or rotation are in sync with each other.

So here is no mystery,. but i still think it is a interesting and fascinating clip.

The video frame rate and propeller rotation are so much in sync, they almost look like stil.
During they entire take of the props must have had a fairly constant speed. Wich i find remarkable, but i guess it would be because of modern engine control systems.

Anyway, nuf talking , here is the little clip:

a reply to: EartOccupant

The props are just a cover for the antigravity system.

a reply to: Zaphod58

I do find it quit interesting the RPM of the props are so stable during take off.

Are those engines geared? I like the kind of control it seems to have,

a reply to: EartOccupant

It's the engine control unit. Once you set it to takeoff power it keeps the RPMs as stable as possible. A lot of them are moving to digital units that are both better and worse. They're more efficient, but you have to be careful or you end up with a situation like they had with the A400M crash in Spain.

a reply to: Zaphod58

Do I understand it correctly you say they prefer RPM stability (fuel consumption) over perfection?

I would think, as intuition, the more speed the plane in a whole has.. the props would turn faster easier , so with take of you would want more speed, faster props.. ?

originally posted by: EartOccupant
a reply to: Zaphod58

I do find it quit interesting the RPM of the props are so stable during take off.

Are those engines geared? I like the kind of control it seems to have,

Siince the rotation rate of the prop is one of the variables in thrust, it's not really surprising that rpm's are stable. Take off isn't really a phase of flight in which you want large changes in thrust.
In fact, turboprops generally have a variable-pitch prop so that the rpm can remain at an efficient rate for the particular engine, and the thrust can instead be adjusted by changing the "bite" of the prop for a great deal of the flight envelope.


ETA: helicopters are even more exciting with stereoscopic effect. Looks even more unnatural because we are used to seeing planes without propellers, but less so with a helicopter

I had a beanie hat with a propeller when I was a young one.
I was disappointed that I never took flight.

I had a beanie hat with a propeller when I was a young one.
I was disappointed that I never took flight.

I had a beanie hat with a propeller when I was a young one.
I was disappointed that I never took flight.

I had a beanie hat with a propeller when I was a young one.
I was disappointed that I never took flight.

a reply to: EartOccupant

On takeoff you want consistent power. Props tend to create torque that can pull you off the runway if you were to have one engine at a higher setting than the other. So they try to equalize power and keep it consistent.

the video cameras pick the easiest display, that's why they can look curved which is the coolest thing

so cool

originally posted by: EartOccupant
a reply to: Zaphod58

Do I understand it correctly you say they prefer RPM stability (fuel consumption) over perfection?

I would think, as intuition, the more speed the plane in a whole has.. the props would turn faster easier , so with take of you would want more speed, faster props.. ?

yep, at altitude we will blow the cylinder heads clean off if we don't mess with it all, the constant speed prop takes a mind set change...gotta be checked out in every different type of prop or else.

a reply to: Zaphod58

I get the picture now tnx, i guess i was just a little taken by the precision.


a reply to: GBP/JPY

I can imagine that!

a reply to: EartOccupant

Some people on ATS would think this was a holographic projection, or a glitch in the Matrix.

a reply to: Zaphod58

This is how rumors get started.

/smh

a reply to: grey580

If you can't beat them (and you can't, I checked with the police and a lawyer) might as well join them.

a reply to: Zaphod58

well..... depends on how much you have in the bank..

However it is cheaper to just join em.

originally posted by: Zaphod58
a reply to: EartOccupant

The props are just a cover for the antigravity system.

Thanks a pantload Zaph! I just blew my watered down Micky-Ds diet Coke all the way up and out my nose.

a reply to: SonofaSkunk

Glad I could help.