VS problem at cruise

I have always had a problem in most aircraft with the vertical speed at cruise. I make sure my VS isn’t too much when approaching my altitude so it is a smooth level out (usually no greater than 1,000 vs). However usually a minute or two after I level out at cruise, my vs starts to become greater and greater, moving from about +900 to -900 vs and not sure why and then my plane starts to bop up and down. I usually have my trim at 0% or about 0-20%. Any tips?


On what aircraft is this happening?

You may be too heavy for your altitude.

1 Like

Building on the above, it would be helpful to know the following to help diagnose root cause:

  1. Which aircraft you are flying
  2. Typical cruise speed when this occurs (and engine power - normal cruise is typically 80-86% N1 in most situations)
  3. Typical cruise altitude when this occurs
  4. Typical aircraft load when this occurs
  1. It usually occurs on the Crj, 737, and a320 family because is what I fly most
  2. I usually travel at about .78-.82 during cruise
  3. Lower altitudes are better and seems to start about FL300
  4. Aircraft is usually about half full

Very helpful info - thanks for sharing! That seems to rule out most of the “usual” causes, so probably best for a mod / IF staff to weigh in on this one…

Ok thanks for your help anyways!

Hi! I suggest maybe trying a lower altitude as you might be too heavy. Then you can step climb as you proceed with your flight.

Hope that helps!😊


Same problem here dude, i always cruise between FL280 and FL320 with speed of 0.78 on the B738 but when auto pilot reaches to the altitude that i’ve set, aircraft turns into a rolling coaster (btw i always do have a weight of around 67 tons)

1 Like

Sounds weird, it never happens to me.

This topic was automatically closed 3 days after the last reply. New replies are no longer allowed.