Simviation Forum - Help FS2002 planes go up and down.

Jan 27^th, 2004 at 11:52am

Dark Knight Offline
Colonel
I'm hungry
Keene,NH U.S.A.

Gender:
Posts: 25

Ok,So i start a flight from Manchester
with learjet 45 to Logan int.After i get
up to about 8,000 feet my plane wants
to go upwards slightly or it wants to nosedive. Sad

HEEEEEEEEEEEELLLLLLLLLLLLLPPP!!!!!!!!!!!!!!!!!!!!!!!!!!!! Cry

Play that funky music white boy!!!&&&&I'm talking bot the FUNK.

Back to top

IP Logged

Reply #1 - Jan 27^th, 2004 at 5:51pm

Scottler Offline
Colonel
Albany, New York USA

Gender:
Posts: 5989

Aren't planes supposed to go up and down? lol

In all seriousness, I'd try either adjusting the aircraft trim, or re-calibrating your joystick (if present).

Great edit, Bob.&&&&&&Google it. &&&&www.google.com

Back to top

IP Logged

Reply #2 - Jan 27^th, 2004 at 9:50pm

Travis Offline
Colonel
Cannot find REALITY.SYS.
Universe halted.
Dripping Springs, TX

Gender:
Posts: 4515

I've always noticed that FS planes tend to oscillate up and down, no matter what you are flying. It tends to happen more the higher you go in the atmosphere, so it must be something to do with either pressure or temperature, or a combination of both.

I first noticed this when I would fly extended flights across the Atlantic and up the sim rate to 16x to get through those long bits. Almost any aircraft (other than large passenger jets) seems to have this quirk, so don't be alarmed. Just let it happen smoothly, and you won't change more than about 200 ft either way.

Back to top

IP Logged

Reply #3 - Jan 28^th, 2004 at 2:45am

simone_lux Offline
Colonel

Gender:
Posts: 27

Quote:

I've always noticed that FS planes tend to oscillate up and down, no matter what you are flying. It tends to happen more the higher you go in the atmosphere, so it must be something to do with either pressure or temperature, or a combination of both.

I first noticed this when I would fly extended flights across the Atlantic and up the sim rate to 16x to get through those long bits. Almost any aircraft (other than large passenger jets) seems to have this quirk, so don't be alarmed. Just let it happen smoothly, and you won't change more than about 200 ft either way.

Yes, it's right

There is a solution, for this:

1) Disengage for a moment the IAS or MACH Hold Switch (better when the throttle is almost stable).

2) When the plane is at its minimum oscillation "leg" (which is a sinusoidal loop), and trying to rise again, disengage immediately the "altitude hold" switch.

3) The plane should very slowly go up, with increasing v-speed, but nothing fast as the oscillation.

4) When the plane is less than 20 feet from the assigned altitude, re-engage Altitude Hold switch.

5) The plane will remain there, but it will sometimes restart oscillating ! As soon as it reach the altitude is better to re-engage the IAS hold.

6) If the procedure doesn't work, even by increasing the time between altitude and ias hold re-engaging, it means that your IAS setting for that ALTITUDE with that AIRCRAFT is not correct. Increase or decrease IAS by 10-15 kt (if you are near the maximum speed, decrease of course !).

Wink

Meteorologist as hobby,&&Simone Lussardi

Back to top

IP Logged

Reply #4 - Jan 29^th, 2004 at 3:08am

Poseidon Offline
Colonel
Athens, Hellas

Gender:
Posts: 412

The Learjet tends to go up and down as well as the other jets in FS2002. It takes concentration and very fine adjustments in the trim in order to "hit" the exact configuration and yet after some time (minutes) you may need to trim again (wind, pressure conditions). This attitude appears in all airplanes but much less in a Cessna or a Baron.
On the other hand the autothrottle in FS2002 is a bit slow in response which causes the effect untill it balances at a specific configuration. Are you using time warp? If you set it to 16x the autopilot will never be able to balance. Even if you start the time warp from a balanced position the deviation will increase up to an annoying point. I have experienced the last one with all the jets in FS2002.

Back to top

IP Logged

Reply #5 - Jan 30^th, 2004 at 6:31am

microlight Offline
Colonel
It's a bird...
Southern UK

Gender:
Posts: 2236

Good points, all. I do exactly what Simone says to counteract the problem.

The effect is sometimes more noticeable with add-on planes, where the flight dynamics are perhaps not as refined as the could be. I had a 767 that would 'porpoise'as soon as you got over around FL250, whereas of course the real thing doesn't do it. A different 767 model didn't do it, and the difference appeared to be in how the dynamics were configured. Small adjustments in the aeroplane geometry and engine thrust helped to minimise the problem.

BAe ATP for FS9 now available! www.enigmasim.com

Back to top

IP Logged

	Search the archive: