DCS: AH-64D Flight Model discussion

[kenbou]

I know after 90 degrees.
I'm looking at the speed at which the main rotor tilts.
For example, referring to this video, what I want to say is
This is the frequency of precession when a torque perpendicular to the axis of rotation is applied.
The higher the torque and the lower the mass or rotation, the higher the frequency.
Compared to applying torque to a non-rotating object,
When a torque is applied to a rotating body in a direction perpendicular to the rotation axis,
If the torque is the same, it will tilt slowly.
Non-rotating and rotating
https://www.youtube.com/watch?v=XPUuF_dECVI&t=1455s
https://www.youtube.com/watch?v=XPUuF_dECVI&t=2150s
Does the DCS AH-64D have a rotor that tilts like this?

[admiki]

7 hours ago, kenbou said:

I know after 90 degrees.
I'm looking at the speed at which the main rotor tilts.
For example, referring to this video, what I want to say is
This is the frequency of precession when a torque perpendicular to the axis of rotation is applied.
The higher the torque and the lower the mass or rotation, the higher the frequency.
Compared to applying torque to a non-rotating object,
When a torque is applied to a rotating body in a direction perpendicular to the rotation axis,
If the torque is the same, it will tilt slowly.
Non-rotating and rotating
https://www.youtube.com/watch?v=XPUuF_dECVI&t=1455s
https://www.youtube.com/watch?v=XPUuF_dECVI&t=2150s
Does the DCS AH-64D have a rotor that tilts like this?

Again, are you flying Apache or MD500 in real life? If you don't, then all your ideas how it should behave are just guesses. Just like when people that have never even seen it in real life made their opinions how autopilot and trim release should work in Mi-24.

If a real life Apache pilot like Brad says that's how it's supposed to be I tend to roll with his opinion.

[Raptor9]

8 hours ago, kenbou said:

I'm looking at the speed at which the main rotor tilts.
For example, referring to this video, what I want to say is
This is the frequency of precession when a torque perpendicular to the axis of rotation is applied.

@kenbou, I believe your confusion lies in the fact that you are equating the AH-64's rotor system to a single rotating body, and thus subjecting it to the same physics.

Some rotation physics apply to the rotor system, like gyroscopic precession, but the main rotor is not a rotating body like a wheel. It is composed of four individual airfoils, not something like a control moment gyro or a reaction wheel like you are describing.

There have been rotor systems that incorporate gyroscopic stability into the design to take advantage of the effect you are describing, but these require a single rotating body to do so, like the Lockheed CL-475. But the AH-64 is not one of these types of helicopters.

[unairspace]

In straight and level flight, pull back the cyclic will cause the vertical speed cue to drop very quickly then rise slowly and vise versa. That's new in the current FM. Is that normal?

[admiki]

1 hour ago, unairspace said:

In straight and level flight, pull back the cyclic will cause the vertical speed cue to drop very quickly then rise slowly and vise versa. That's new in the current FM. Is that normal?

Vertical speed cue? Or are you talking about acceleration cue?

[unairspace]

6 hours ago, admiki said:

Vertical speed cue? Or are you talking about acceleration cue?

Sorry, the vertical speed indicator and flight path vector will both move to the opposite direction first when you pull or push the cyclic in flight, then move back to where they should be.

Edited November 13, 2023 by unairspace

[Floyd1212]

Maybe the radar altimeter is located in/near the tail  and as you yank the stick back the tail drops and briefly shows a reduction in altitude before the aircraft starts to climb?

[bradmick]

The rad alt doesn’t have anything to do with the flight path vector, velocity vector or acceleration cue. The Flight path vector is a full 3D representation of the current aircraft’s velocity. Typically the FPV is controlled via collective, but when you accelerate or decelerate you can also push or pull the FPV because you’re imparting some form of vertical velocity when you pitch forward or aft with the cyclic. It goes back to normal when you adjust the collective to “balance” the forces acting on the helicopter.