WARNING: AFM : GC adjustments

[squirel]

Chuck Norris can do it, so shut up.

[OSD]

This post is deleted!

[Shadow]

This post is deleted!

[Shadow]

So GC for the SU-30 is different from its CG with consideration to its 5 fuel tanks position and quantity ??

[A.S]

@Mav-jp:

For your information

i read on the internet people proposing a “Realism Patch for BMS and advertising a GC displacement in the AFM files !!!”

Yes there is a mistake in the F16 - B models where the fuel tanks are misplaced leading to excessive AFT GC and leading to excessive roll departures.
Sorry for that mistake this will be fixed in next update.

All other F16 variants are SPOT ON.

The F16C is designed for a GC positioned at 0.35MAC which corresponds to internal fuel loaded aircraft.
At GC design the F16 is subject to roll departure and during mission the GC is going AFT and is becoming more sensitive to roll departure.

changing GC values would lead to:

1. wrong behavior vs roll departure
2. wrong performance in term of G loading and unloading
3. wrong performance in term of take off capabilities
4. wrong Aerobraking behavior
5. wrong yawing beahavior and bad SAS behavior
6. bad gun compensation
7. wrong deep stall conditions

years of research and real documentations have been used to create those AFM, i strongly advise for full realistic experience to trust only BMS distributed AFM and not trust any “i know F16 is like that” that you could read on the internet.

I use the term “Realism Patch” for Redflag, because ALOT of work has gone into it from many perspectives, BUT i do NEVER EVER touch anything in the sim-data folder, nor do i “displace” stores.
Big no no tabooo here. That much understanding i have.

[Shadow]

I’ll try one more time.
Is there a difference between “CG” & “GC” as used in the xx.dat file and the xx_afm.dat file.

Or is this a inconsistant use of the same parameter wrongly used in the FM ?

The only thing I can think of is that “CG” is a referance to LOD model’s central reference for stores/component placement. And how do the two relate to each other ? (Yes I dont use lod editor but have had look some time ago)

I do realize common referance is from the AC “nose”

Thanks for any usefull informative responce……Shad

[Buzzbomb]

This might be a really good place to ask this question:

Remote controlled scale F-16 models are fairly popular in the RC flying community. I’ve heard of them being made as large as 1/4 scale.

Assuming that those RC scale models are reasonably accurately modeled, it seems to me that they’d have the same relaxed static stability as the real thing. Thus, they should be intrinsically unstable. But as far as I know, no RC model has a FLCS embedded in it to manage that instability.

So they have to be doing SOMETHING to make the model stable enough for manual control. By chance, do you have any idea what modifications the RC builders are making to the design to make it stable enough to be flown manually?

[Blu3wolf]

@Buzzbomb:

This might be a really good place to ask this question:

Remote controlled scale F-16 models are fairly popular in the RC flying community. I’ve heard of them being made as large as 1/4 scale.

Assuming that those RC scale models are reasonably accurately modeled, it seems to me that they’d have the same relaxed static stability as the real thing. Thus, they should be intrinsically unstable. But as far as I know, no RC model has a FLCS embedded in it to manage that instability.

So they have to be doing SOMETHING to make the model stable enough for manual control. By chance, do you have any idea what modifications the RC builders are making to the design to make it stable enough to be flown manually?

I would guess either moving the center of gravity towards the nose, or moving the wings further back than the real deal.

During design of the jet, they were designing the plane at the same time as the FLCS - and they were not actually sure they could get the whole RSS gimmick to work!

So, they hedged their bets.

They planned the airframe so that it would work with the FLCS, if the FLCS worked - and if it didnt, they would move the wings aft and that would make the aircraft stable, though at the cost associated with stability - pitch damping and thus slower nose response.

Turns out, the FLCS worked

EDIT: now wouldnt that be something? a model F-16, with an inbuilt FLCS to manage its instability… would add a whole lot of weight for a model aircraft though… dunno if thats feasible. Cool idea though!

Probably wouldnt do much, other than improve its performance beyond similar models which are statically stable.

[l3crusader]

@Blu3wolf:

I would guess either moving the center of gravity towards the nose, or moving the wings further back than the real deal.

During design of the jet, they were designing the plane at the same time as the FLCS - and they were not actually sure they could get the whole RSS gimmick to work!

So, they hedged their bets.

They planned the airframe so that it would work with the FLCS, if the FLCS worked - and if it didnt, they would move the wings aft and that would make the aircraft stable, though at the cost associated with stability - pitch damping and thus slower nose response.

Turns out, the FLCS worked

EDIT: now wouldnt that be something? a model F-16, with an inbuilt FLCS to manage its instability… would add a whole lot of weight for a model aircraft though… dunno if thats feasible. Cool idea though!

Probably wouldnt do much, other than improve its performance beyond similar models which are statically stable.

IMO they simply have the CG forward and basta. For the FLCS to work, you need AOA probes and Pitot, at the very least….

[TR0UBLE]

I happen to have one of these RC Planes and yes the CG is moved forward… when they make FLCS for RC we can change that