Simviation Forums

I just got back into Flight Simulator 2004 after 3-1/2 years away from it; I've forgotten quite a bit about it and am reacquainting myself with much of it and all the extras I used to be into, so it's slow going. Anyway...

I tried to research into this through the forum search, but here goes: I have a few aftermarket aircraft (free- and payware) doing the ol' taxi-bounce: rolling along at 10-15 knots, the nose begins to bob ever so slightly, then it gets worse and worse until the nosegear collapses...and that's it. The worst part of it is that it also affects my one of my favorites, the payware JustFlight Duchess twin...all the time. Frustrating. The PC is a new Core 2 Quad Dell (made in 2007 but never left its box until I got it last month), the FS2004 install is fresh and I also upgraded to the 9.1 patch. No effect.

Like I said, I forgot much of what I knew, would anyone have any insight on what to do to remedy this? JustFlight says they never heard of the issue with their Duchess. I'm intrigued as to why this doesn't happen with the stock aircraft which come with the program.

One more thing I might add: I added on a couple hundred .BGL files of various airports I cleaned up (through AFCAD), that's about it. Any help would be appreciated, thanks!

It's a problem with contact points. The contact points for the nose wheel of that particular aircraft are not right.

If other aircraft taxi with no problems than you have a contact point problem. It could be the nose wheel or it could be the main gear or all of the above . Changing contact points can be a head ache if you do not know what you are doing. You can cause your aircraft to be buried in the ground or float above the ground.
I would suggest you compare it to a similar type aircraft that does not have this problem.
An example a B737-300 should be the same no mater what variation it is Delta Southwest Or what ever. the contact points should be the same as long as the aircraft are similar types
If other aircraft do this as well than your problem is with the runway itself it is not defined correctly or there is interference with some default scenery that can cause this as well.
One other cause is excessive taxi speed can create the bouncing effect. 10 to 15 MPH is the standard with 15 being on the high side I keep mine under 12 MPH.

No more aircraft that you have installed I would do a complete delete and reinstall and see if that might help.

Actually moving back the contact points for the main gear (often by less than a foot) can fix this.

Thanks, I'll go ahead and look into the contact point issue. I've been getting back into CFG files, looking up various XYZ coordinates; I know planes can have different zero references, so I'll pay close attention to that. Much of this thing is slowly coming back, thankfully, just gonna take awhile is all. Thanks to all of you for your input, it helps a great deal!

Okay, did some comparative digging and digesting of the overall contact points format: dug up the Baron 58's points as well as the Duchess' points and what struck me is the datum for the nosegear. What concerns me is the #4 item in each line, the impact damage threshold, on each plane's various points: The Baron's impact damage threshold on all three gear legs is 1600, whereas on the Duchess, a lighter plane (and the plane in question), the impact damage threshold for the three gear legs are varied...the mains have 1200, the nosegear has 5000??? Does that hold any significance? That's a high number in comparison to the Baron, which has no nod-n-crunch tendencies. I might back that 5000 to 1200 to match up, see what happens. Any thoughts on this? Thanks again!

Hi,

The impact values will not affect bouncing on the runway, only the threshold where a crash will occur.

The only time I have suffered from bouncing aeroplanes, (FS 2004), is when I have installed some scenery and/or mesh, where the elevation of the airfield and/or runway is different, higher/lower, than the default elevation.

Easiest cure for me is to delete the problem scenery in the add-on scenery list.

Paul.... ...!

Like Paul, I've only experienced 'bouncing' when there's a glitch in a Scenery pack...

You mention updating .bgl's... could that be where the issue lies?

Alan

ViperPilot wrote:Like Paul, I've only experienced 'bouncing' when there's a glitch in a Scenery pack...

You mention updating .bgl's... could that be where the issue lies?

Alan

..... ....!

I've got no time for Flight Sim "problems" nowadays, Alan.

If something doesn't work in the Sim....I just dump the problem, and carry on with the rest if it!

I'm too old for stress.... ....!

Motorcycling/Sim Flying around Denver, Colorado (You Tube) is a great stress reliever!.... ...!

Paul.... ...!

Paul,

You been watching the Weather lately? Better put that sickle in the carport, and make a pot of Tea, 'cause it's gonna get COLD!

https://weather.com/weather/tenday/l/USCO0105:1:US

Pay particular attention to Saturday & Sunday...

Still think we live in the Desert?

Alan

ViperPilot wrote:Paul,

You been watching the Weather lately? Better put that sickle in the carport, and make a pot of Tea, 'cause it's gonna get COLD!

https://weather.com/weather/tenday/l/USCO0105:1:US

Pay particular attention to Saturday & Sunday...

Still think we live in the Desert?

Alan

Its a funny old do, Alan!

At the moment its freezing in Bakersfield, CA, and a cool 50*F in Florida!

Its all very strange to me!

Wildly varying temperatures in areas which I always assume to be HOT...all the time!

My English temperatures at the moment are similar to North Carolina!

New England is quite cold. and Ontario is up to its ears in deep snow!

I wonder what its like in Phoenix, Arizona?...Nice and warm and cosy?

Paul....I need Warmth....and no Bouncing!.... ...!

I've considered the latest posts, so now after thinking about it: the BGLs I mention are essentially airports modified via AFCAD (I've modified a couple hundred, it's a hobby). I've never had the bounce-crash happen on a runway, only a tarmac or taxiway. Through some trial-and-error on AFCAD, making scenic roads around an airport, I've noticed that off-airport roads tend to cut through any small rolls in the land or elevate low spots, so I do believe the taxiways make anything equal in level to the airport...but just because the terrain appears flattened, is it truly flattened? And I don't know if tarmac octagons have any levelling properties themselves, haven't gone that far yet. If that's the case, is there any way to flatten a larger area without resorting to one of the late, great Opa's Tricks & Tips? Can it be done invisibly?

Finally, regarding the contact points: Ive seen CFGs in which the aircraft vary in where their fuselage station zero-datum occurs: some zero at the firewall, others zero at the factory CG. Any insight there? I'll try the Duchess again later tonight, when the 3 little girls are asleep, see what happens on a taxi run. Thanks again!

I have the same problem with the Justflight Duchess bouncing during taxiing in fs2004 sometimes, I couldn't find a solution either it doesn't seem to do this in FSX. I will have a look at the duchess over christmas and see if I can improve it in Fs9.