Cyclic - can't maintain attitude?

Rigid, Semi-Rigid or Fully Articulated refer to whether the blades can swing lead lag, flap etc.

A Rigid head has blades designed to flex to provide the flapping action required to address dissymmetry of lift etc in flight rather then having a hinged and or pivoted arrangement to facilitate flapping and lead lag. The angle of the blade is still controlled via rotation at the root for blade pitch control via swash plate.

Rigid Rotor info here.

AFAIK The Gazelle has a semi-rigid design with independent blade flapping and lead/lag movement.

Good picture of 341 Rotor head here.

Rigid, Semi-Rigid or Fully Articulated.

 

AFAIK The Gazelle has a semi-rigid design with independent blade flapping and lead/lag movement.

I’d say the Gazelle has a fully articulated rotorhead.

Semi rigid is two bladed, like Huey, Jetranger and Robinsons.

Its just called semi rigid, they are not “almost” rigid like the Bo.

Ah gotcha. :) :thumbup:

Waiting for Bo 105 I might break it less often. All of a sudden I'm having problems with rolls in the Gazelle broke 2 last night, boom strike I think. :cry: :D

I have a lot to learn about helicopter engineering. What about this Sikorsky X2 Rigid Concept.

Q for those in the know. Does DCS: Gazelle properly simulate rotor inertia. Seems like if there is power loss, while IGE hover, it drops like stone.

Alright clearly not in the know, however there is lower mass in the rotor system so less energy.

I am wondering why you question that does the rotor RPM droop?

In hover you seem to rise up and down but you feel the need to use the collective a lot?

For me I'm hard pressed to get rotor droop, the most that seems to happen is over torque turbine/transmission and I try to stay out of that zone. ;)

Smaller rotor gives you a smaller boundary on the cushioning effect so you may need to keep the rotor attitude more neutral with less (over) correction.

Talking about rotor heads I did well, some googling and check this out, especially the way they do the rotor head and how they tie in the blades. OH-6.

Q for those in the know. Does DCS: Gazelle properly simulate rotor inertia. Seems like if there is power loss, while IGE hover, it drops like stone.

Alright clearly not in the know, however there is lower mass in the rotor system so less energy.

Theres a very big difference depending on the rotor inertia. Two bladed helos with semirigid rotors tend to have quite high inertia. To make a helo with teetering rotor less prone to mast bumping I think that a heavy rotor with lot of gyro effect is needed.

So, for the Bell 206 you can hover at 10 meters and with the correct collective management still land safely without bending the helo if engine quits( done this lot of times in B206).

While not trained on the Huey, I know it has a lot of more mass making it even more forgiving.

On the opposite, the schweizer 300 has a very low inertia rotor. You should’nt be much more than one meter above ground and you have to act immediatly and use all collective stick movement if engine quits. Still the landing wont be very firm. (Done this also lot of times).

Helikopters with fully articulated rotors ( or rigid like the Bo105) are much lighter and Id say, if hovering and loosing the engine(-s) more then 1.5-2m height, the arrival wont be soft and you need to react within half of a second.

I only have the Huey, and I think its somewhere in the ballpark around the real one( yes I did autos from hover with it, not advanced ones, just normal hover).

But I think again, if you didnt do it IRL and you try to think you know from another DCS module

how a helo should react, you might be extremely out.

Think that doing a engine out from hover with a Huey is like catching a shuttlecock/feather ball, then doing the same with a Schweizer 300 is like catching a 10kg kettlebell.

For the Gazelle, it would be like a 2 or 4 kilo kettlebell.

Its extremely different, if you see what I mean.

For much heavier helos the mass of the rotor system isnt that much more compared to the engine power needed to turn the rotors in a hover. The rotors would stop very quickly if you loose both engines at the same time. Dont know the blade weight for the mi-8 but you could think that you have much less time to react compared to the huey.

Theres a very big difference depending on the rotor inertia. Two bladed helos with semirigid rotors tend to have quite high inertia. To make a helo with teetering rotor less prone to mast bumping I think that a heavy rotor with lot of gyro effect is needed.

 

So, for the Bell 206 you can hover at 10 meters and with the correct collective management still land safely without bending the helo if engine quits( done this lot of times in B206).

While not trained on the Huey, I know it has a lot of more mass making it even more forgiving.

 

On the opposite, the schweizer 300 has a very low inertia rotor. You should’nt be much more than one meter above ground and you have to act immediatly and use all collective stick movement if engine quits. Still the landing wont be very firm. (Done this also lot of times).

 

Helikopters with fully articulated rotors ( or rigid like the Bo105) are much lighter and Id say, if hovering and loosing the engine(-s) more then 1.5-2m height, the arrival wont be soft and you need to react within half of a second.

 

I only have the Huey, and I think its somewhere in the ballpark around the real one( yes I did autos from hover with it, not advanced ones, just normal hover).

 

But I think again, if you didnt do it IRL and you try to think you know from another DCS module

how a helo should react, you might be extremely out.

 

Think that doing a engine out from hover with a Huey is like catching a shuttlecock/feather ball, then doing the same with a Schweizer 300 is like catching a 10kg kettlebell.

For the Gazelle, it would be like a 2 or 4 kilo kettlebell.

Its extremely different, if you see what I mean.

 

For much heavier helos the mass of the rotor system isnt that much more compared to the engine power needed to turn the rotors in a hover. The rotors would stop very quickly if you loose both engines at the same time. Dont know the blade weight for the mi-8 but you could think that you have much less time to react compared to the huey.

Yes I have not done power fail at hover but followed through with IP, A second or so is all. :)

Yes I have not done power fail at hover but followed through with IP, A second or so is all. :)

R44?

For reference:

Easy to here the chop off off the throttle.

Yes R44 that's how it was done back throttle off, it's pretty immediate.

Yes R44 that's how it was done back throttle off, it's pretty immediate.

And the R44 teetering rotor should have some mass, making it hangin’ a little better. Not like a Huey, but :)

(Theres another factor that helps: a few long blades with less cord needs less power to be driven, and the other way around will stop less quick).