Fix the UH-1H's collective.

[Heliflyr]

Many people in DCS say how the UH-1H is the closest sim to the real helicopter. The Huey is a module I regularly use and enjoy. With the recent release of the reworked F-5, the UH-1H also needs a rework. The one thing that bugs me the most is how the collective has a major influence on the huey's pitch in relation to the fuselage. How the collective works in real helicopters is that it controls the increase of all the main rotor blades pitch and allows the helicopter to climb or descent vertically. It does not control the pitch of the fuselage. The cyclic controls the fuselage pitch through forward, aft and side to side movement. In DSC, the player should only need to use collective inputs to increase or decrease height above the ground in a hover or in flight while the cyclic inputs will control the helicopter's pitch and roll. I made a 3:39 video flying around Tbilisi using only the collective and tail rotor inputs. For takeoff and landing is the only time cyclic inputs are used. 

https://youtu.be/Xq4ZSvcwm14

 

Edited April 23 by Heliflyr

[Calabrone]

I watched the video carefully and will try. I will fly with the fixed collective and correct any pecking with the cyclic. Will let you know !

[LuseKofte]

On 4/23/2025 at 8:37 PM, Heliflyr said:

Many people in DCS say how the UH-1H is the closest sim to the real helicopter. The Huey is a module I regularly use and enjoy. With the recent release of the reworked F-5, the UH-1H also needs a rework. The one thing that bugs me the most is how the collective has a major influence on the huey's pitch in relation to the fuselage. How the collective works in real helicopters is that it controls the increase of all the main rotor blades pitch and allows the helicopter to climb or descent vertically. It does not control the pitch of the fuselage. The cyclic controls the fuselage pitch through forward, aft and side to side movement. In DSC, the player should only need to use collective inputs to increase or decrease height above the ground in a hover or in flight while the cyclic inputs will control the helicopter's pitch and roll. I made a 3:39 video flying around Tbilisi using only the collective and tail rotor inputs. For takeoff and landing is the only time cyclic inputs are used. 

https://youtu.be/Xq4ZSvcwm14

 

It would be wrong if it not did have any effect on pitch in the real world. And I don’t quite see the problem either. 
It might be close to reality flying, but if I bother to be bugged by anything, I rather look into its DM. And compare it to MI 8. MI 8 got together with Hind the best DM among all choppers in DCS and Huey got loss of rotor. 
mot is basically dead meat getting fired at, if you don’t fly the rotor off it get shot off. 
It would have been a good module in msfs , it got a lot of reasons for a upgrade , your problem are last of them in my opinion, but could gladly be looked into

[Calabrone]

Dear Heliflyr, the Huey, compared to even more decorated helicopters, has a perfectly implemented flight model and has to fly that way. I suggest you watch this video and you should have the answer to your question! Hi !

 

[Heliflyr]

On 4/27/2025 at 9:11 AM, Calabrone said:

Dear Heliflyr, the Huey, compared to even more decorated helicopters, has a perfectly implemented flight model and has to fly that way. I suggest you watch this video and you should have the answer to your question! Hi !

 

Hey Calabrone, I watched that video. What he is talking about is totally unrelated to what I was saying about the collective having a profound effect on the helicopter's pitch. The collective, in no way has that kind of influence on the vertical pitch of the helicopter irl. Flying the DCS huey is manageable the way it now. but believe me it is a constant fight when making assertive collective inputs, like having to enter an autorotation at high speeds. Most of the time the huey ends up like a lawn dart. I demonstrate a 180 deg auto in another video, but the cyclic was trimmed for the maneuver and I was prepared for the extreme nose down attitude that was going to occur when I bottomed the collective.

Edited April 29 by Heliflyr

[Heliflyr]

On 4/26/2025 at 5:36 PM, LuseKofte said:

It would be wrong if it not did have any effect on pitch in the real world. And I don’t quite see the problem either. 
It might be close to reality flying, but if I bother to be bugged by anything, I rather look into its DM. And compare it to MI 8. MI 8 got together with Hind the best DM among all choppers in DCS and Huey got loss of rotor. 
mot is basically dead meat getting fired at, if you don’t fly the rotor off it get shot off. 
It would have been a good module in msfs , it got a lot of reasons for a upgrade , your problem are last of them in my opinion, but could gladly be looked into

LuseKofte , don't misunderstand when I say "Pitch," that I'm referring to the pitch of the rotor blade, because I'm not. I'm talking about helicopter attitude, nose up and nose down. The cyclic inputs influences the attitude of the helicopter in flight and autorotation. The Huey in DCS, have both the collective and the cyclic controlling the helicopter's attitude. Get that fixed and the Huey will fly like the real thing.

 

[Wrcknbckr]

I think what you are seeing is that increasing collective in hover, is increasing rotor downwash on the horizontal stabilizer resulting in a pitch up attitude. Unlike other manufacturers Bell puts a this stabilizer under the rotor to compensate pitch down at forward speeds. Other helicopters have the horizontal tail further back.

[Heliflyr]

On 4/26/2025 at 10:59 AM, Calabrone said:

I watched the video carefully and will try. I will fly with the fixed collective and correct any pecking with the cyclic. Will let you know !

Putting the collective in a fixed position defeats the problem. What I did was just let go of the flight stick (Cyclic) after getting airborne and used the collective to raise and lower the nose while using the tail rotor pedals to control heading. As you have seen, raising the collective puts the helicopter into a very nose high attitude that I was able to perform hammerhead turns. Once at the top, I lowered the nose with the collective and pushed full right pedal making the turn facing down. Before crashing into the ground, I once again raised the collective to bring the nose up to parallel the ground. This is not the correct function of the collective.

Edited April 29 by Heliflyr

[Heliflyr]

15 minutes ago, Wrcknbckr said:

I think what you are seeing is that increasing collective in hover, is increasing rotor downwash on the horizontal stabilizer resulting in a pitch up attitude. Unlike other manufacturers Bell puts a this stabilizer under the rotor to compensate pitch down at forward speeds. Other helicopters have the horizontal tail further back.

Hey Wrcknbckr, if ED implemented that into the huey's flight model they would be wrong. The helicopter is very sensitive when it comes to loading of passengers and cargo because the cg moves mostly from aft to front during the flight as it burns off fuel. A helicopter that is full of fuel and had a fully loaded baggage compartment along with any passengers in the back seats will put the cg near its aft limits. If downwash had that much influence on pushing the horizontal stabilizer down like you say, that will surely push the cg even farther aft putting the helicopter out of control because the pilot will not have enough forward cyclic to stop the helicopter as to begins to move backwards. Believe me, the downwash has very very little influence pushing the tail boom down in a hover. Otherwise the RFM would warn pilots about the risk of rotor downwash forcing the cg further aft in a hover. 

[Wrcknbckr]

6 minutes ago, Heliflyr said:

Hey Wrcknbckr, if ED implemented that into the huey's flight model they would be wrong. The helicopter is very sensitive when it comes to loading of passengers and cargo because the cg moves mostly from aft to front during the flight as it burns off fuel. A helicopter that is full of fuel and had a fully loaded baggage compartment along with any passengers in the back seats will put the cg near its aft limits. If downwash had that much influence on pushing the horizontal stabilizer down like you say, that will surely push the cg even farther aft putting the helicopter out of control because the pilot will not have enough forward cyclic to stop the helicopter as to begins to move backwards. Believe me, the downwash has very very little influence pushing the tail boom down in a hover. Otherwise the RFM would warn pilots about the risk of rotor downwash forcing the cg further aft in a hover. 

Of course the CG envelope is determined including this effect. It's not that this effect is excluded in the design

[Heliflyr]

3 minutes ago, Wrcknbckr said:

Of course the CG envelope is determined including this effect. It's not that this effect is excluded in the design

Of all the helicopters I've flown, I never experienced a downward force on my horizontal stabilizer that made me worry about raising my collective was going to cause my tail boom to possibly hit the ground when I was near aft cg limits. Also, none of the RFMs or recurrent classes I attended ever mentioned anything about it.

[Wrcknbckr]

33 minutes ago, Heliflyr said:

Of all the helicopters I've flown, I never experienced a downward force on my horizontal stabilizer that made me worry about raising my collective was going to cause my tail boom to possibly hit the ground when I was near aft cg limits. Also, none of the RFMs or recurrent classes I attended ever mentioned anything about it.

Exactly, because that aft limit was based also on pulling collective, so no need address that specifically in a manual. Since you have flown helicopters (Bell included?), can you say something about pulling collective and notice a pitch up (I supposed OP is referring to pitch up...), are you then compensating automatically?

[Heliflyr]

3 minutes ago, Wrcknbckr said:

Exactly, because that aft limit was based also on pulling collective, so no need address that specifically in a manual. Since you have flown helicopters (Bell included?), can you say something about pulling collective and notice a pitch up (I supposed OP is referring to pitch up...), are you then compensating automatically?

First, the horizontal stabilizer surface area is small when you compare it to diameter of the main rotor disc. Downwash will flow over and around it just as it flows down and around the forward deck and along the nose. Most of my career was in Bell helicopters. When you preform a maximum performance takeoff from a hover, you don't have to push forward cyclic to maintain your position in the climb because again the horizontal stabilizer surface area is too small to cause the helicopter to pitch nose up. when you look at eh Uh-60 horizontal tail, it is huge. I would imagine it is angled down to prevent the helicopter from pitching because of downwash. But I never read the RFM on it, so idk.

[Heliflyr]

It seems that most of the replies have not been about the root of the problem that I see and would like to be fixed. And that is that in DCS the UH-1H can pull out of a nose dive using only the collective with no input from the cyclic. Which in the real world, is totally impossible. If you break your cyclic in the real thing in a dive, pray that your life insurance is paid up so your family will be taken care of. As it is now, flying the DCS huey has 2 controls that will influence the helicopter's attitude which are the cyclic and the collective. The collective being the incorrect input device to control helicopter attitude needs to be fixed. I have a feeling that because the collective is modeled incorrectly, it may also be causing some of the mast bumping problems that a lot of players are complaining about.

[Wrcknbckr]

That's good to know from your operational experience!

I'm still looking for a physics-based explanation. Let's stick to a hover case. It's not that the stabilizer area is too small. It's the moment it creates with a down force on it. Assuming the lateral moment caused by fuselage to be zero (forward deck equals out with backward engine deck) than with increasing collective it should lead to a pitch up. 

Which leads us to the fuselage. Fuselage aerodynamic characteristics may come into play when the airflow comes from above creating a pitch up moment. I wonder to which extend that is modelled in DCS.

UH60 horizontal surface is huge indeed, but is placed outside of the rotor disk, with a scheduled angle depending on forward speed, the Huey's stabilizer is placed inside the rotor disk. 

[Heliflyr]

Keep looking, there are studies out there about the effects of downwash. Because manufacturers need to know the dangers that can destroy their helicopter. I'm sure you will find that by design the amount of degrees of nose up is very marginal and not noticeable to the pilot. There are so many aerodynamic forces acting on a helicopter that is noticeable that pilots are taught about it, such as dissymmetry of lift, transverse flow effect, blowback (flapback) and others. Again this is off topic from my original post and need to be on its own thread. And if you seen the video I posted, I'm demonstrating the collective's effect on helicopter pitch in forward flight that is extremely noticeable. So pronounced that I have hands off my joystick control during the flight. 

[Wrcknbckr]

I just flew the DCS Huey after a long time and indeed the pitch up and down in forward flight raising collective is clearly noticeable. My initial line of thinking was with hover in mind but raising collective for a vertical climb did not lead to a perceivable pitch up/down. So I  guess it's something within the flight model that's off for forward flight.