Hello I down loaded a third party aircraft but when it is at cruising altitude it bobbs up and down. How do i stop this. Thanks in advance Shaun.

What do you mean by bob up and down? Is it a bounce or slow movement? Is the auto pilot on? We need more info. :)

I'm having the same problem with an Eastern 727 I downloaded. Flies great until you reach FL190. Then after that the aircraft oscilates up and down during the rest of the climb as well as during cruise. Auto pilot is on. The vertical climb gauge will fluctuate between +800 and -800 at cruise. During climb it will go as high as +2500 and as low as -2500. And the aircraft reacts just like a dolphin in the water. Any help is appreciated. Bob

This is what it's called in the real world of flight. I have found that a lot of the addon aircraft that are available, have this problem, which seems to be uncorrectable. However, I have found that after reaching cruise altitude, if a porpoise is evident, just disengage the A/P, stabilize the aircraft, and reengage the A/P, and all will be well. Now, a non A/P porpoise during climb, I have never experienced. Just set the trim for whatever VV you want, and sit back until target altitude is reached.Gheers,Layabout

Found a tip in the database that might help you:http://www.fsgateway.com/tips_read.asp?id=7http://fsgateway.com/images/frank.jpgwww.FSGateway.com

I don't suppose the 3rd party a/c you are referring to is DF734? If so, forget getting rid of the pitch oscillations. I gave up long ago!There are parameters in FSedit that you can play with such as 'pitch stability'. Tho these have had no affect on DF, they may work for other a/c.Good luck ;) Adam