Crashing the black shark!

[RvETito]

That's exactly what I did![/QUOTe]

 

;););)

[RvETito]

Hmmn - interesting point, there's got to be a scenario in which that is a problem.

 

IIRC we decided you get yaw in the Ka50 by increasing pitch on one set of rotors and decreasing on the other - so if you increase pitch on the lower rotor and decrease on the upper, while banking and pulling G, the risk of rotor clashing becomes a nice problem . . . .

 

Question now is, which way does each rotor turn and so is this represented by a lower tolerance for errors when throwing the aircraft around in one particular direction?

 

I'll quote myself:

The blades' colision is aslo part of the AFM. This is the major drawback of the coaxial rotor design. The worse combination of control input is to pull hard on the cyclic at high airspeed and to push the right pedal(this increase the collective pitch of the lower rotor and decrease the collective of the upper with the same angle).

 

The upper rotor turns clockwise looked from above.

[Weta43]

AirTito - I read this "Two separately mounted engines at a maximum distance reduce the probability of their simultaneous damage. The powerplant has an operational life of 30 minutes without oil, giving the pilot the opportunity to land in a safe location in the event that the oil system is damaged in combat. The helicopter also has duplicated and stand-by hydraulic and power systems and main control circuits. " & assumed that this included the gearbox.

http://www.military.cz/russia/air/helicopters/Ka_50/ka50_en.htm

[nscode]

I have a video of it!

 

It's so nice that YOU have a video of it.. you can recreate it anytime, and we will be able to when we get our copy, but what would be sooooo nice, now, is that you show that video to US :) ;)

[hitman]

I have a video of it!

What are the chances to see this video???

[Force_Feedback]

What are the chances to see this video???

 

Nil? Close to zero? Not once in your life? Never while you're alive? No way hose? When pigs fly?

[RvETito]

AirTito - I read this "Two separately mounted engines at a maximum distance reduce the probability of their simultaneous damage. The powerplant has an operational life of 30 minutes without oil, giving the pilot the opportunity to land in a safe location in the event that the oil system is damaged in combat. The helicopter also has duplicated and stand-by hydraulic and power systems and main control circuits. " & assumed that this included the gearbox.

http://www.military.cz/russia/air/helicopters/Ka_50/ka50_en.htm

 

Thanks for the link. Look at the table down of this page. See what it says?

 

....Power plant

two TV3-117VMA engines...

 

So these 30mins are concerning the engines, not the gearbox. Although the powerplant is assembly of the three components(each engine and the gearbox has an indipendant oil system), they have had to be more specific in this site. But yes, the engine is capable if running dry.

[Crusty]

I just want to add that if the tail rotor fails in the single main rotor design the result would be a certain crash, even if you disconnect the engine(s) from the main gearbox- i.e. go into autorotation. There won't be anything to balance the torque of the main rotor and the helicopter with jammed tail rotor will start to spin in direction oposite to the rotor's.

 

Sorry but thats wrong when in autoration there is no torque reaction

in fact its something I practice with my model helicopters, ....take engine to idle(drive clutch disengages)...tail rotor slows down and stops and you autorotate down keeping some forward speed and airflow over the rear to weathervane and flare for landing, its standard procedure if you get a tail control failure

the above refers to systems where the tail drive is not mechanicaly connected to the main rotor when engine stops driving, there are also helicopters with a "driven tail", that remains mechanicaly connected to main rotor when engine stops,...these allow a modicum of directional control during autorotation as they are kept spinning by the mains

[hitman]

Nil? Close to zero? Not once in your life? Never while you're alive? No way hose? When pigs fly?

Think we're due for a new video anyways...dont you agree? The one thats posted has been there for a while, while Flaming Cliffs had a new one basically every month.

[Force_Feedback]

Think we're due for a new video anyways...dont you agree? The one thats posted has been there for a while, while Flaming Cliffs had a new one basically every month.

 

But aren't you afraid that we'll get spoiled, I mean so much information in one week, engine management, rotor AFM, damn, I might end up in one of those looney bins. :/

 

Yeh, a vid would be cool, and pick some Rastafarian music for it, with lots of ganja references in it. (I'm making a "Gnaja Farmer" movie BTW:p)

[hitman]

gawd...loony bin? Youd be in a loony bin the instant BS came out, tryin to figure out what all these shiny bells and whistles do. I want some vids, and I think were long overdue for some....

[NEODARK]

Can the Ka-50 pull a 360 loop?

 

(do you remember that old movie blue thunder I think) and it was likea huge feat to aclomplish this?

 

so, can it?

[GGTharos]

Yes.

[Shepski]

It's so nice that YOU have a video of it.. you can recreate it anytime, and we will be able to when we get our copy, but what would be sooooo nice, now, is that you show that video to US :) ;)

 

I'd love to show it to you but it's not up to me... sorry.

[Shepski]

 

Yeh, a vid would be cool, and pick some Rastafarian music for it, with lots of ganja references in it. (I'm making a "Gnaja Farmer" movie BTW:p)

 

The music I used is "One" by metallica.... so not even remotely close. :)

 

I'll upload it for Eagle to see then they can decide but I wouldn't hold my breath!

[RvETito]

Sorry but thats wrong when in autoration there is no torque reaction

 

Nope, you're wrong. If there's no torque reaction there would be no torque. If there is no torque there would be no rotation. If the rotor RPM in autorotation is the same as in motor fligth the torque that drives the main rotor shaft would be of the same magnitude as the engines can supply but with the opposite direction. Or, when in powered flight the rotor works as a propeller(converting engines' power into thrust), while in autoration it works as a turbine(converting the airflow's energy into mechanical energy). The only differnce is what supplies the torque- the engines or the airflow.

[Guest IguanaKing]

A change in rotor pitch will also cause a change in torque, regarless of whether the engine is running or not. However, I have been told that main rotor torque isn't quite as much of a problem in a helicopter with coaxial main rotors like the Black Shark. That does make sense.

[Honest989]

:confused: I left this thread for like 6 hours and it's turned into this behemoth! Airtito! how do you know so much?!?

 

I guess this means i need to go learn a little something about co-axial helicopters in order to get some decent skill at flying the BS...

 

 

 

Oh... btw.. if anyone is planning on modding for BS when it's out... do an AH-64 D please :p

[Swartz (LT)]

I had a clip i put together of low level flight, Same stuff as Shepski, i did a few tricks in a hanger with dust kicking up. FPS when dust kicks up is really not to much of a problem. It's all up to ED on the next video release.

[RvETito]

A change in rotor pitch will also cause a change in torque, regarless of whether the engine is running or not. However, I have been told that main rotor torque isn't quite as much of a problem in a helicopter with coaxial main rotors like the Black Shark. That does make sense.

 

Yep, the torque is a function of the collective pitch- the bigger the pitch is the greater torque must be applied to maintain rotor's RPM. And in a single rotor design you must also increase T/R pitch to balance the increased torque reaction. Modern helicopters have automatical devices that do that for the pilot so he doesn't need to work with the pedals when increase/decrease collective. Coaxial rotor design don't need such devices and this is one of it's advantages- control indipendancy in each channel.

 

Let me tell you few things about coaxial rotors. The flow from the upper rotor twists downstream and increase both- horizontal and vertical component of the airspeed vector of the lower rotor(both rotates at the same RPM in the opposite direction), so the UR is like a boost stage for the LR. Because of this the LR works in worse conditons and has bigger loads. And because both rotors runs at the same RPM the lower has bigger torque reaction. To equalize torque momentums between the rotors the LR has 1'15"(Ka-32 here, it should be about the same value for the Ka-50) smaller pitch and this difference is kept constant in the entire collective and cyclic pitch ranges.

 

I can talk for hours about Kamov helicopters because that's what I do for living. I'm trying to not go to much in details and heavy theory because this a flight simulator board, not a dedicated tech discussion. And from what I hear about BS I'm getting more and more optimistic about it.

[Crusty]

Nope your way off, WHEN THE ROTOR IS NOT DRIVEN by an engine mounted in the fuselage THERE IS NO TORQUE reaction to the fuselage, go read up you dont have to take my word

Why do you imagine that certain helicopters driven by tip jets dont require an anti torque device?

this is basic physics, guys:rolleyes:

[Crusty]

Nope your way off, WHEN THE ROTOR IS NOT connected to a gearbox or engine mounted in the fuselage THERE IS NO TORQUE reaction to the fuselage, go read up you dont have to take my word

Why do you imagine that certain helicopters driven by tip jets dont require an anti torque device?

this is basic physics, guys:rolleyes:

 

I think the confusion is down to the fact that many full size helos dont fully dissconect the rotor from the drive in such sutuation and are still spinning some on board componants,,, but a true freewheeling rotor does not transmit power (torque) to whatever is hanging below it, autogyros are another example, ever seen one of them with a tail rotor?

[RvETito]

I'll still disagree with you. Neither example you gave(rotary wings and autogyros) has a hard mounted gearbox which transmits engines' power to the the rotor(s). All they need is a bearing junction which if is well lubricated won't transmit almost any torque. The torque reaction in helos occurs exactly in the GB and is transmitted to the fuselage via the GB hard support mounts. Like you said- simple physics- to have a rotation you must apply torque momentum, when you do that a torque reaction at the same magnitude and opposite direction will occur in the rotational body mounts(if there are any)- 3rd Newtons's law of mechanics. In autorotation the rotors don't transmit torque back to the engines since they are disconnected by the freewheel, that's true but the torque reaction is transmitted to the fuselage not by them but the GB.

[Crusty]

Yes if the main rotor is still driving a gearbox, it will have a torque reaction....I think I allready said that, but not all helicopters do this, if the main rotor has a one way bearing (sprag clutch) there will be to all intents and puposes no torque transmission between rotor and fuselage

[RvETito]

Yes if the main rotor is still driving a gearbox, it will have a torque reaction....I think I allready said that, but not all helicopters do this,

 

Ah, we finally found a common language:) To tell you the truth I don't know about gas-turbine helicopter without such design- hard connection between the rotor and the gearbox. I appreciate if you or anybody else could prove me wrong hence I will learn something new. The idea of such design is that the gearbox drives also essential aircraft componets like hydraulic pumps, generators etc. The Ka-50 has two 208V three-phased AC generators, two NP92A-5 multipiston variable displacement hydraulic pumps, oil-cooling fan driveshaft and rotors RPM sensor and all this is driven by the gearbox. So in case of both engines failure you'll have electrical and hydraulic power available to land safely at autorotation.