AH-1W SuperCobra

[bell_pilot]

Welcome to the Forum Bell_Pilot.
Best,
IH-COL

Thank you!
What IH-COL stands for?

[bomber]

My next suggestion would be to involve the FGUK team in this as much as possible.

Now I understand these guys don't like me, I don't know why, I've never offended anyone on their forum so I can only assume they've built a general picture of me having argued with Thorsten for a year or two and decided to pick a side. That said they do have some dedicated people interested in helicopters and I think a merger between their 3d/2d and a jsbsim flight model would be a perfect outcome.

Can I also suggest you download the existing Huey and my JSBsim flight model for it. Because if in your opinion it's rubbish you (I) need to know as early as possible where it fails so as to put it right.

[bomber]

Is the pilot in the front seat ?

[bomber]

The first task as I've mentioned is to understand the weight, CoG and the distribution of this weight from the rotation point to establish the inertia values...

Code: Select all

   <mass_balance>                                                         
                                                            
      <!-- inertia values to rotor co-ords -->                                                      
      <ixx unit="SLUG*FT2">12522.6934854718</ixx>                                                      
      <iyy unit="SLUG*FT2">23727.1471711975</iyy>                                                      
      <izz unit="SLUG*FT2">11703.6760803716</izz>                                                      
      <ixy unit="SLUG*FT2">-20.8983301404626</ixy>                                                      
      <iyz unit="SLUG*FT2">-136.621585792705</iyz>                                                      
      <ixz unit="SLUG*FT2">1153.44411436399</ixz>                                                      
      <emptywt unit="LBS">8565.74319991733</emptywt>                                                      
      <location name="AERORP" unit="IN">                                                      
         <x>0</x>                                                   
         <y>0</y>                                                   
         <z>0</z>                                                   
      </location>                                                      
      <location name="CG" unit="IN">                                                      
         <x>2.26378894666849</x>                                                   
         <y>-0.26533512652744</y>                                                   
         <z>-73.3586973376084</z>                                                   
      </location>                                                      
                                                            
   </mass_balance>

Can I suggest using the rotor head as the datum, this is unless the documentation you have has it differently, in which case go with that.

regards

Simon

[bell_pilot]

Is the pilot in the front seat ?

No, both of seats can fly the aircraft but there are some differences.
Front seat is gunner/copilot's
-Fly helicopter with all instruments except variometer. Cyclic is more stiff.
-Has fundamental engine instruments such as torque and rpm ind.
-Can fire gun turret (with TSU/NTS* and HSS**), tow and hellfire,rocket(by pilot-override situation, not practicable, maybe for ultra-emergency situations)
-Cannot start engine but can shut down in emergency

Back seat is pilot's
-Fly helicopter with all instruments.
-Has all engine,cbox and xmsn instruments
-Can fire gun turret(HSS or fixed***), hellfire, rocket
-Full systems control.

*TSU/NTS- telescopic sight unit/night targetting system is used by gunner. Basically gunner will control turret with joystick, by screening on mfd.
**HSS- helmet sight unit: control turret with head movements, basically fire where you look at.
*** Fixed: Pilot selects fixed position for turret. And then turret take position of zero pitch-azimuth wrt. helicopter. Basically fire where the nose of helo towards.

I hope you guys can imagine what i write.

[IAHM-COL]

What IH-COL stands for?

That's my nickname

IH stand for my name's initials. COL stands for my country of origin.

[bomber]

So I guess you're not getting anywhere with FGUK if you use a JSBsim fdm ?

They'd rather continue down the yasim road they've put hours into than accept it's failures and move on.

[bell_pilot]

Can I also suggest you download the existing Huey and my JSBsim flight model for it. Because if in your opinion it's rubbish you (I) need to know as early as possible where it fails so as to put it right.

I did. But i am not sure if i installed your model right.

The first model has lots of errors, it is more alike H-300 rather than Huey.
Governor is not working well. When i give left cyclic input for banking, it is good. But if a add backward cyclic to this maneuver RPM drops suddenly. If i dont collective down, i crash. Is this happen in real? No. You bank 70 degs and pull cyclic towards to your belly, the Huey turns 180 deg backwards in 5 secs.
Helicopters loses its stability in ground-effect and bounce up when above 1ft ground. I tried to approach, everything was quite good until the groundeffect. Especially huey lost its yaw stability, sthng like a lost my tailrotor.

Helicopter slips on the ground when the collective full down. this is a bug i guess.

Engine Gas/Turbine indicator (N1,NG) is not working right. Normally while engine works, NG value is around 89-92, not below. Idle is around 62. While flying, this value waves between 92-101.5 wrt to the power need. But in this sim, it was working like a pitch degree indicator.

The final and the most important thing is the Transmission Torque Indicator was missing.
I couldnt see how much i applied collective input. The torque indicator is everything for huey pilot. It is almost impossible to flight without it. Cos' Ng indicator is not static. You may see 101% with 12 deg collective pitch in a normal day. But some another day, consider it as HOT, you may see %101 with 10 deg collective pitch.

These things must be fixed. Also Huey is not so sensitive as in the simulator.
Aerodynamics control effects are modelled well. When pull collective up, you must give left pedal input with forward cyclic simultaneously. I showed all these effects well but they were somehow exaggerated i guess. More flights needed to consider this well.

What i did with your model is:

I installed default hangar in-game Huey model and copied your huey files into this folder. Then i run the simulator. What i see is the same helo model. The helo was slipping on the ground and i stopped. Could someone give me the instructions for that?

So I guess you're not getting anywhere with FGUK if you use a JSBsim fdm ?

They'd rather continue down the yasim road they've put hours into than accept it's failures and move on.

I would like to test their yasim model first before deciding to a start-over with JSBsim.

[bomber]

Ok sounds like a good start... Plenty to sort out, what to do first ?

Mmmmmmmmm

[bell_pilot]

Ok sounds like a good start... Plenty to sort out, what to do first ?

Mmmmmmmmm

I guess you misunderstood. The first model was not yours. I am not sure if i ve correctly installed your model or havent.