Originally Posted by
T1032L
This is my first post. I am not a pilot but an aviation geek. I was outside today in the late afternoon in the Chicago area and spotted a 747 overhead at cruise altitude with a contrails from each engine—it was N-NW bound. There appeared to be something unusual with one of the engines which is why i am posting. Every 3 to 5 seconds a large puff of white contrail came out of the left outboard engine. This happened as long as i saw the craft. All the other 3 engines were putting out a steady contrail. The plane of course landed ok at MSP.
Is this abnormal for an engine to do that?
I checked the radar plot and it looks like it was UPS 2560 from Louisville to MSP. N579UP according to RadarBox.
I will leave the driving to you all! thanks
I have had my share of chemtrail fun over the years, but the most likely answer to your question comes from the fact that the inboard and outboard engines on the 74 have a 3 degree difference in their mounting. This can lead to some odd contrail behavior.