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tooner

AH-1Z Viper helicopter flight model

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Hey Tooner awesome work. I think what the guy meant is that the rotors can only withstand a certain amount of G-forces and flutter. Just like the wings of planes. Imagine diving with a small plane at a high altitude increasing the speed of the small plane until it reaches a really high speed and then trying to do a loop. The G-forces will snap the wings off in the worse case. This means that all planes have a certain speed they must never exceed, because either the flutter or the G-forces will risk destroying to aircraft.

 

The same is valid for helicopters I belive. If you exceed the max velocity of the cobra and do something like rolling, a loop or even more simple things you risk the rotors breaking off due to the G-forces. Even just going too fast will damage the heli due to a thing called flutter.

 

 

 

It all depend on angular acceleration. You can not be over max speed put if you perform a very tight loop ie very high angular acceleration, you can still damage the aircraft. Nowadays all modern aircraft has FBW where flight control surfaces received the pilot input after being analyzed by flight computers and will modify the pilot input if for example it estimate that he will put the aircraft outside the flight enveloppe.

But also all modern fighter has FBW and flight control software not only for protection but for making the aircraft flyable as all modern fighter aircraft is aerodynamically unstable to gain better maneuverability but the flight control computer is there to make it flyable for the pilot, if a failure happens on the flight control computer, the pilot would only be able to eject. If I recall correctly, the f16 was the first aircraft with FBW and full digital control surface ( pilots inputs analysed by the flight control computers and then sent to the actuator to move respectly the flight control surfaces. Bear in mind that in full digital flight control , the pilot by moving the stick ask for a new flight path when stick is released in neutral position, the flight control computer will check if it's possible without going out of the flight enveloppe and if yes, then will ajust the flight control surfaces and trim the elevator accirdingly to meet the pilot demand

 

@ElektroCmbelite-FR - I don't know which would solution would be better in the end, full manual control and allow blade snapping or try to make it FBW-like which would prevent snapping, I have to read more about it in the future.

 

@Xx-RAGING-DEATH-xXRykaneIronComatoseunfrail - thanks! it's really great opportunity for me to work with them :)

 

 

Did you ever get this to a public release state? I would be very interested to mess around with it.

 

Not actually a public release, but it's very playable :) Here's a download link - http://bit.ly/1BJ0oJw 

The key config is in the readme file (same folder as main .exe), be sure to check out TV cam from high altitude F10 (switch cam) and backspace (high/low respawn). I was inspired by this vid and tried to make it look similar - 

 

 

Rotor collision?

 

Otherwise, stop making me so wet.  :wub:

 

Rotor collision is a must have!

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@ toner

Well if the Viper has FBW and flight control computer, then it would be impossible to put the viper outside its designed flight envelope, but if the pilot has full control of the control surfaces ie direc law=> pilot can put the viper outside the flight envelope.

The thing to bear in mind is that with FBW and flight control software is that the pilot by deflecting the joystick to 5 deg will result for example a roll rate of 2deg/sec, 10 deg of deflection will result a roll rate of 4 deg/ sec and this whatever are the speed and altitude of the viper as long as the viper is in its flight envelope

So the pilot by moving the sidestick demands a change in pitch and roll rate and for the same joystick deflection will result the same rate at any speed or altitude, the flight control software will ajust accordingly the flight surfaces.

However in direct law a 10 deg deflection will result in a k*10 deg on the flight surfaces and the K is constant.

So for exemple at 150kts, a 10 deg deflection on the joystick will result on a 12deg roll rate. Now the speed is at 200kts and the pilot use same 10deg deflection on the joystick , the roll rate will be increased at 16 deg per sec for example. The roll rate would have been the same is the aircraft has got FBW and full digital flight control.

I only know this for commercial aircraft and I can't tell you if there is any FBW and full digital flight control on military helicopter

I'm only sure that the new Airbus helicopter NH90 has FBW and full digital......

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Well I googled AH 1Z FBW and find something interesting

With the H1 upgrade, the viper has FBW but nothing mentioned a flight control software , FBW means that the joystick and the flight control surfaces are no longer linked mechanically but electrically with his a huge advantage as weight is drastically decreased.

So you can still have FBW and direct law like the embraer 170-190

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Howdy everyone.

 

Just wanted to put it out there that I am a commercial helicopter pilot and instructor and I would be happy to answer any questions I can regarding helicopter aerodynamics and flight controls. I always loved the helicopters in PR and before that, desert combat (I always thought those were the most real feeling helicopters I had flown in a game). 

 

In regard to mast bumping and rotor separation, the reason you don't see it anymore in military aircraft is because they all have more than two rotors now. Old hueys and cobras used an underslung see-saw type rotor system that allowed rotor flapping around a pivot attached directly to the main rotor mast. Under the right conditions (primarily low-g) the rotors could flap in excess of the maximum range and the rotor head would strike the mast on every revolution. Since the rotors turn around 400rpm, the effect of catastrophic mast bumping occurs nearly instantaneously resulting in main rotor separation. The upshot is that rotor systems with more than two blades have flapping hinges (if they have any at all) arrayed around the outside of a flex-plate so that no amount of flapping will result in striking the main rotor mast. Aircraft like the BO-105 actually have no hinges and all of the flapping and lead/lag forces are absorbed through the rotor blades themselves, resulting in an extremely maneuverable aircraft, which is why red bull uses it as an aerobatic display aircraft.

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Great sounds

 

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Creek,

 

welcome to forums and game!

 

Thx for offering help! I'm sure this will be noted by developers or modder. Developers probably already took a note. Maybe it would be best if you start your own thread so this would get more attention?

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I could post it in a new thread. Do you think I should put it in feedback and suggestions?

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Good question... just put it there and if it's not in proper place, mods will move it.

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