Aircraft specific runway bounce.

[Meco]

Bounce = excesive G forces or crash even when your doing everything right.

Im sure this has happened to many who use planes other than the default FS9 planes.

When flying with a default plane, take off's and landings go smoothly with regards to runway level / stability.
The problem only seems to occure with some add on planes and at select airports. IE: CYYZ.

I can fly any default plane and I dont get the bounce. But the following add-on planes Bounce on the runway during takeoff, landing, and
even on the taxiway at any speed.

- AC500
- DH8-300 Horizon
- Excalibur
- Concord

I also have many other add on planes that dont bounce at all.

As such I am inclined to think its a contact point problem rather than a scenery problem. otherwise if it was a scenery problem would it
not affect all the planes?

So in trying to find a solution to the problem I am including my contact points for my Concord.

[contact_points]
point.0=1.0, 5.667, 0.0, -16.300, 1181.102, 0.000, 2.100, 100.0, 0.250, 2.000, 3.000, 5.000, 8.0, 0.0, 0.0, 0.0
point.1=1.0, -54.0, -12.7, -17.000, 1850.805, 1.000, 2.700, 0.000, 0.500, 2.500, 0.920, 7.900, 7.9, 2.0, 0.0, 0.0
point.2=1.0, -54.0, 12.7, -17.000, 1850.805, 2.000, 2.700, 0.000, 0.500, 2.500, 0.920, 8.500, 8.5, 3.0, 0.0, 0.0
point.3=2.0, -14.167, -47.33, 0.0, 1388.141, 0.0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 5.0, 0.0, 0.0
point.4=2.0, -14.167, 47.33, 0.0, 1388.141, 0.0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 6.0, 0.0, 0.0
point.5=2.0, -116.667, 0.00, -0.83, 1574.803, 0.0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 9.0, 0.0, 0.0
point.6=2.0, 47.667, 0.0, -6.67, 787.401, 0.0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 4.0, 0.0, 0.0

Now I want to try and fix the problem but I don't know enough about the points and how they work / effect the plane.

So Im asking for anyone that knows what each line is for so I can attempt to modify some of those values.

Each line has 16 number sets seperated by ( , )
What does each set mean? do?

Looking at the first point.0 for example.

What do the following values mean / do?

1.0
5.667
0.0
-16.300
1181.102
0.000
2.100
100.0
0.250
2.000
3.000
5.000
8.0
0.0
0.0
0.0

Any input would be greatly appreciated for a better understanding of how I can work on solving this issue.

[Meco]

Ok I think I got a better idea where I need to test some modification of the contact points.
As above mentioned theres a lot of numbers for each point. here is a break down of what they mean / do.

1.0 – wheel <0=none,1=wheel, 2=scrape, 3=float>
5.667 – Located in front of reference point
0.0 – units to the side of reference point
-16.300 – units below of reference point
1181.102 – crash activation value FPM
0.000 – no brakes (1 = left break, 2 = right break )
2.100 – wheel radius
100.0 – steer angle
0.250 – static compression
2.000 – Max static compression
3.000 – dampening ratio
5.000 – Gear extension time
8.0 – Gear reaction time
0.0 – sound types
0.0 – Airspeed limit for retraction
0.0 – Airspeed that gear gets damage at.


The rear wheels is were the bounce seems to be coming from so Im testing adjustments on:

- static compression
– Max static compression
– dampening ratio

To see if I can smooth out the bounce cause / effect. I found some interesting properties when comparing Add-on planes versus the
default FS9 planes (Aircraft CFG) . and from those differing values, I believe its helping me to see what direction I need to change the
numbers so that the plane acts stable like the Default planes yet still have the intended feel the author of the Add-on plane had in mind.
IE: it wont be very good If I get rid of the bounce but the wheels are rendered 2 feet above. or worse yet 2 feet below the ground.

So Im testing some new numbers for the Concorde Example above and will try a flight to see if my hunch was correct.

I shall reply with my findings for those that are interested in dealing with the Bounce factor of add on planes.



Post Edited ( 06-13-06 01:52 )

[poden]

Meco:

I've been wanting to fix some of the bounce problems I've encountered too; it'll be interesting to hear back.

[Meco]

Still working on it.

There seems to be a needed balance of those numbers. its not just as simple as setting only one new variable and it's fixed.. at least not
yet.

But I am continuing to try some new stuff. I should have results soon.

I was able to smooth out the concord by quite a bit.

I use to bounce when trying to take off with it, which resulted in an excessive G penalty almost every time. usualy greater than 5 G and
screeming pax for good mesure... but I got it down to 3 G and no more screeming about it. So improving.

I been in contact with a couple other testers regarding this problem. and collectively were narowing down the formula to smooth it out
almost to no bounce at all. as it turns out the CG height seems to be playing a big role in the problem beyond the contact points.

IE:

static_pitch=-0.20
static_cg_height=16.025 <-- (this one)
gear_system_type=1

Small adjustments in this one alone is proving to be a good fix. but not perfect.

So once we get it to no bounce at all, or at the very least an absorbable lump with no G penalty. then we will try to arrive at a general
formula based on those adjustments. Then I will try to apply it the other bouncing planes in hopes that the % formula we are making for
3 of the needed number changes will be a step in the right direction.

The long part is the testing itself after each little change. because to just start FS9 and try the change does not reflect a full blown flight
with Active sky 6, AIsmooth, FS Real Time & FSP loaded flight all running at the same time. I made the mistake of thinking I had it solved
with a quick start of FS9 only. Then I loaded a regular flight and " Boing"... So the testing needs to take place at full flight status and under
different weight loads and CG balances.

At least it's starting to make more sense than when I first started.

Ill keep at it



Post Edited ( 06-14-06 08:09 )

[Joeflyer]

It seems the only airplane I seem to bounce at all is the Captain Sim B727-200. It's hard to nail the landing on that airplane in real time or
in the sim