Centric nature of the cyclic in the Gazelle.

[exil]

Experience from the real world: Fuel quantity no, loadout maybe.

 

As for fuel: Tanks are build within the Center point of gravity to counter the effect that if you burn Fuel, the h/c is running out of cg limits (which totally makes sense when you think about ot from an engeneers perpective).

 

As for loadout: it depends...if you load two hot, one on each side it wont have an significant impact on cg. If you load the same two hot to one side only it will.

[Jester986]

There should be a slight right roll in the Gazelle when picking but not related to the location of the fenestron, but because it takes right cyclic to counter the left translating tendency. I can't speak specifically to the Gazelle but usually a roll associated with a collective input is due to the mixing unit. Its a gadget I cant wrap my head around the combines both the cyclic and collective movements from the control tubes before sending them to the swash plate. Blowback causes a nose up pitch as you accelerate that you have to push through on your take off run because of the disymetry of lift you mentioned.

[FragBum]

There should be a slight right roll in the Gazelle when picking but not related to the location of the fenestron, but because it takes right cyclic to counter the left translating tendency. I can't speak specifically to the Gazelle but usually a roll associated with a collective input is due to the mixing unit. Its a gadget I cant wrap my head around the combines both the cyclic and collective movements from the control tubes before sending them to the swash plate. Blowback causes a nose up pitch as you accelerate that you have to push through on your take off run because of the disymetry of lift you mentioned.

 

Yes I felt that transitioning form hover to climb, set power and as you gain forward speed you really need to push the cyclic more and more forward for the initial part of the climb then it pretty much settles whilst you maintain climb rate and speed. But not so much with the Gazelle.

[borchi_2b]

2: Question: does the gazelle unbalance when there are missiles fired and for example 2 tubes filled on

one side and the opposite side is empty ?

 

ANSWER:

Barely noticable. Only noticable on transitions at low speeds in hover and low speeds

if there are a fat crewchief and 2 Missiles on one side which will unbalance the helicopter a bit.

 

 

just to show you guys one of the direct answers

[myHelljumper]

[...]fat crewchief[...]

 

How do you fit a fat crewchief in a gazelle, look at the guys we have in it, they already fit barely :D.

 

You might need to use a shoehorn :megalol:

[FragBum]

There should be a slight right roll in the Gazelle when picking but not related to the location of the fenestron, but because it takes right cyclic to counter the left translating tendency.

 

Just thinking about this if the aircraft is in balance yes some cyclic and some anti torque and collective input, if its all balanced shouldn't it just pick straight up with no real roll or pitch or yaw?

[Jester986]

A helicopter is inherently out of balance. Left thrust from the tail rotor takes right cyclic to counter. That right cyclic gives you a right skid low hover.

 

 

***Disclaimer I'm happy with the flight model, I just try to correct helicopter misconceptions when I see them.

Edited November 1, 2017 by Jester986
Clarity

[sc_neo]

As i said earlier, i am pretty happy with the Gazelle overall and appreciate the work going into the FM, especially that the devs are inquring with RL pilots flying the version we have in DCS world. So i consider my question about ''no roll'' on lift off answered, as borchi positively stated that he received confirmation that there is no roll on pick up with whatever loadout.

 

What do i take away from this discussion we were having about the FM? First, i myself need to invest more time into reading about helicopter design and flight principles.

 

Second, if i kindly may suggest to borchi_02; simmers come with varying degrees of knowledge about flight principles etc. to the forums and i reckon, its everyones own job to read up on it. But, this is mostly limited to the general case, but more often than not this will not apply to the very module in question. Simply put, we probably cannot read about the Sa-342M in detail unless in the manual that comes with the DCS module.

 

Hence, i would suggest to put a 2 to 3 page description/explanation about the modules fm paritcularities into the manual. Just describe briefly the main forces and important aspects for the different flight states and than contrast this with how the aircraft, the Gazelle in this case, behaves and or differs from the general case. The general stuff would probably be a good deal of condensed copy and paste from a authoritative flight principles book, and then the application or reflection on the Gazelle in particular. For instance, concerning the question about roll on pick up. You could briefly explain the forces responsible for this behaviour, mention the various design principles to counter that tendency and then shortly outline haw the Gazelle is designed to deal with this.

 

I guess this might clear up a lot of misunderstandings and doing this for future aircraft as well, might save a lot of hussle and time spent on us nagging about small stuff on the forums :)

[borchi_2b]

The idea is not a to bad idea, it depends right now if such a reding of 2 pages would end in the desired results.

 

I have a plan for the future module to maybe have the community ask questions on a lifestream event as soon we think we can show something. I already talked to the chief testpilotabout that idea many month ago and since he is a good friend of mine he agreed for such a session. We thought about doing similar suff for the gazelle, but since english is not the nativ language of the french army pilots we scratched that for now.

 

What I will do is at least 2 tutorial videos for the comunity in the coming weeks.

One will be about the new scout functions that were added to the system andow they can be used in a tactical battlefield.

 

2nd will be about the questions asked and raised by us and the comunity and how this effected the flightmodel in the past weeks.

Also I thought about to explain how the real helicopter is flow by the army ilots and why that is that way.

[sc_neo]

''2nd will be about the questions asked and raised by us and the comunity and how this effected the flightmodel in the past weeks.

Also I thought about to explain how the real helicopter is flow by the army ilots and why that is that way. ''

 

Thats great news. Looking forward to that! And i was totally oblivous to 'the new scout functions'....to really keen on getting to know what that is about!

So best of luck!

[exil]

Sounds great Borchi!

[FragBum]

A helicopter is inherently out of balance. Left thrust from the tail rotor takes right cyclic to counter. That right cyclic gives you a right skid low hover.

 

 

***Disclaimer I'm happy with the flight model, I just try to correct helicopter misconceptions when I see them.

 

Yes I do get that and I probably should have added that, after say bringing the aircraft up so it's very light on the lower skid there is no further roll. The point where it's just coming off the ground.

 

I mean it's already adopted it's hanging position there shouldn't be any dissymmetry of lift at this point unless of course there is wind.

 

That's the concept I'm trying to work through.

[FragBum]

@ sc_neo

 

 

Try this you just need to collect all 15 chapters and it's free.:)

 

Just change ch01 for ch02...ch15 in the URL

 

https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/helicopter_flying_handbook/media/hfh_ch01.pdf

[sc_neo]

Yeah....i have a bunch of them FAA documents laying around, including the 200page complete paper you linked. Gotta go through all of that.