Hi,As the picture explains,when i level out at cruising altitude above 30,000 ft there is a 2-3 degree verticaldeviation.When its less than 30,000 ft the deviation is just a degree.What can be the reason ?While loading the aircraft with fuel and passengers I ensure CG is at the correct level.Please suggest.Ramana V Nandyal

It's not the airflow alone what keeps the aircraft flying, pitch attitude/angle of attack also have something to do. The higher the plane is, the thinner the air is too, so, some degree of more pitch up is needed to compensate the low density of the air.It's normal for airliners to fly with some nose up attitude while in cruise level flight. You can find in airliners.net many cockpit views of the 737NG, and you'll see that 2.5

I wouldn't even call the 2.5-deg attitude a deviation, you are right on according to the FD steering bars. A deviation is when the nose deviates from where it should be such as in turbulence. Your nose is right on the money.Attitude + power = performance. Flying 101, fly around in a C172 at constant altitude and change speed from almost red line to almost stall and watch the nose angle change. The same will happen at constant IAS but varying altitudes.

I wouldn't even call the 2.5-deg attitude a deviation, you are right on according to the FD steering bars. A deviation is when the nose deviates from where it should be such as in turbulence. Your nose is right on the money.Attitude + power = performance. Flying 101, fly around in a C172 at constant altitude and change speed from almost red line to almost stall and watch the nose angle change. The same will happen at constant IAS but varying altitudes.

I am so glad to know that I am not doing anything wrong. Thank you basa and Dan Downs for the replies.Ramana V Nandyal