Strange oscillation with a gulfstream I

[Modlerbob]

I downloaded this bird a while back ( Carlos Armenteros FS2004 US Coast Guard VC-4A Academe, which is a rework of the Mike Stone Saab-340 Freighter) and I have liked the way it handles especially landings. The other night I wasflying it on auto pilot at 24K ft alt. and 190Kts IAS. I left the room for a couple of minutes after it had been flying steadily for about 15 min. From the other room I heard an alarm and the autopilot had disengaged, the plane was pitched way up and had stalled. After a couple of minutes I had it back under control so I turned the AP back on. Over the next few minutes I watched how the plane was flying and noticed it was picking up a rocking motion with the nose pitching up and down. I first it was very slight but over time it got worse until I disengaged the AP again.

OK, this is only a sim on a home computer but I wonder, if the flight characteristics are correctly modeled, whether the real plane has this problem at certain altitudes and speeds.

[miguelangel623]

Owning a Gulfstream, I can personally vouch that it does NOT have an oscillation problem. Must be some glitch in the program. I also do not have this problem in my FSX here on the computer..

[Hagar]

I downloaded this bird a while back ( Carlos Armenteros FS2004 US Coast Guard VC-4A Academe, which is a rework of the Mike Stone Saab-340 Freighter) and I have liked the way it handles especially landings.

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OK, this is only a sim on a home computer but I wonder, if the flight characteristics are correctly modeled, whether the real plane has this problem at certain altitudes and speeds.

I wouldn't expect it to be too realistic. Mike Stone would be the first to admit that his flight dynamics might not be too accurate. Also, it's an FS9 aircraft which might not perform too well in FSX.

[Modlerbob]

Owning a Gulfstream, I can personally vouch that it does NOT have an oscillation problem. Must be some glitch in the program. I also do not have this problem in my FSX here on the computer..

Hey, the Gulfstream is my hands down favorite medium sized twin turboprop both in the real world and on my computer. Were I to ever win the lottery I would pick it as my personal transport. How likely is that to happen?

[YV1202P]

looks like a problem in the AP cfg

by the way theres a REAL MODEL g159 in progress...
http://www.airdailyx.net/fsnewsbreaker/ ... this-plane

cheers

[pete]

Don't forget about Brett Henderson's 340

Plenty of liveries available for it too ...

[ftldave]

I've had aircraft models in FSX show an unnatural, slow oscillation during cruise, but never one as you described. That said, some things you can try for a fix:

In aircraft.cfg, in the Flight Tuning section, edit the "pitch_stability" entry from 1 to 2. Also, edit the "elevator_trim_effectivness" to 2. Or, combine both variables and test the results in flight.